background image

In some measurement situations, however, it would be nice to remove the
need for an ice bath (or other fixed external reference). To do this, an

isothermal block

 is used to make the connections. An isothermal block is

an electrical insulator, but a good heat conductor. The additional
thermocouples created at J1 and J2 now held at the same temperature by
the isothermal block. 

Once the temperature of the isothermal block is known, accurate
temperature measurements can be made. Typically, a thermistor is
mounted to the isothermal block and used to measure the temperature.

Thermocouples come in a variety of types. The type is specified by a
single letter. The following table shows the most commonly used
thermocouple types and some key characteristics of each

MEASUREMENT
THERMOCOUPLE

REFERENCE
THERMISTOR

ISOTHERMAL BLOCK

REFERENCE
TEMPERATURE

METER

Chapter 7  Measurement Tutorial

Measurement Techniques and Sources of Error  

268

Summary of Contents for 34420A

Page 1: ......

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Page 3: ...ermistor thermocouple and RTD temperature measurements Two channel input allows ratio and difference functions for voltage measurements Highly visible vacuum fluorescent display Portable ruggedized case with non skid feet Flexible system features HP IB IEEE 488 interface and RS 232 interface are standard SCPI Standard Commands for Programmable Instruments and Keithley 181 compatibility Readings at...

Page 4: ...lance 1 Input channel select 5 Menu operation keys 2 Measurement function keys 6 Range number of digits displayed keys 3 Math operation keys 7 Single trigger autotrigger auto hold key 4 Filter select key 8 Shift local key 2 ...

Page 5: ...AD HOLD Ø2 TRIG DELAY Ø3 N SAMPLES E SYStem MENU 1 RDGS STORE Ø2 SAVED RDGS Ø3 ERROR Ø4 TEST Ø5 CHART OUT Ø6 CHART SPAN Ø 7 CHART NULL Ø8 DISPLAY Ø9 COMMA Ø10 PRESET Ø11 REVISION F Input Output MENU 1 HP IB ADDR Ø2 INTERFACE Ø3 BAUD RATE Ø4 PARITY Ø5 LANGUAGE G CALibration MENU 1 UNSECURED Ø 1 SECURED Ø 2 CALIBRATE Ø 3 CHART ZERO Ø 4 CHART GAIN Ø 5 INJECTED I Ø6 CAL COUNT Ø7 MESSAGE NOTE The comma...

Page 6: ...mmand error s detected Shift Shift key has been pressed Ch1 Meter input is on Channel 1 Ch2 Meter input is on Channel 2 Ch1 Ch2 Meter is indicating the difference between inputs on channel 1 and channel 2 Ch1 Ch2 Meter is indicating the ratio of the inputs on channel 1 and channel 2 Ω Meter is measuring resistance Ohms LP Meter is using low power Ohms 2W Meter is using 2 wire Ohms annunciator off ...

Page 7: ...ly 6 External trigger input terminal 3 Power line voltage setting 7 GPIB IEEE 488 interface connector 4 Chart recorder output terminal Analog out 8 RS 232 interface connector Use the front panel Input Output Menu to Select the GPIB or RS 232 interface Set the GPIB bus address Set the RS 232 baud rate and parity 5 ...

Page 8: ...mote interface Error Messages Chapter 5 lists the error messages that may appear as you are working with the meter Each listing contains enough information to help you diagnose and solve the problem Application Programs Chapter 6 contains several remote interface application programs to help you develop programs for your measurement application Measurement Tutorial Chapter 7 discusses measurement ...

Page 9: ... an Input Channel 41 To Select a Range 42 To Set or Change the Number of Digits 43 To Set the Integration Time 44 To Make Null Relative Measurements 45 To Store Minimum and Maximum Readings Stats 46 To Trigger the Meter 47 To Use Reading Hold 48 To Make Voltage Ratio and Difference Measurements 49 To Use Reading Memory 50 Chapter 3 Features and Functions General Measurement Configuration 55 Input ...

Page 10: ...tion 101 Remote Interface Selection 101 HP IB Address 102 Baud Rate Selection RS 232 103 Parity Selection RS 232 104 Programming Language Selection 105 Connection to a Terminal or Printer RS 232 106 Calibration 107 Calibration Security 107 Calibration Count 110 Calibration Message 111 Defaults Power On and Reset States 112 Chapter 4 Remote Interface Reference Command Summary 117 Simplified Program...

Page 11: ...s in the Output Buffer 164 The Standard Event Register 165 The Questionable Data Register 167 The Operational Status and Condition Registers 169 Status Reporting Commands 171 Calibration Commands 174 RS 232 Interface Configuration 176 RS 232 Configuration Overview 176 RS 232 Data Frame Format 177 Connection to a Computer or Terminal 177 Connection to a Printer 179 DTR DSR Handshake Protocol 179 RS...

Page 12: ...nts 244 Chapter 7 Measurement Tutorial Measurement Techniques and Sources of Error 249 Voltage Measurements 249 Resistance Measurements 258 Temperature Measurements 263 Cleaning the Connector Contacts 271 Input Connector 272 Obtaining Parts For the Input Connector 273 Chapter 8 Specifications Accuracy Specifications Measurement Characteristics Operating Characteristics Dimensions To Calculate Tota...

Page 13: ...1 Quick Start ...

Page 14: ...o perform a shifted function press Shift the Shift display annunciator will turn on Then press the key that has the desired label above it For example to select the temperature measurement function press Shift DCV If you accidentally press Shift just press it again to turn off the Shift annunciator The rear cover of this book is a fold out Quick Reference Guide On this cover you will find a quick ...

Page 15: ...e meter is left in 61 2 digit resolution channel 1 input and digital filter on To view the display with all annunciators turned on hold down Shift as you turn on the meter 3 Perform a complete self test The complete self test performs a more extensive series of tests than those performed at power on Hold down Shift as you press the power switch to turn on the meter continue to hold Shift for more ...

Page 16: ...dule on the meter s rear panel Verify that the power source is energized 2 Verify the power line voltage setting The line voltage is set to the proper value for your country when the meter is shipped from the factory Change the voltage setting if it is not correct The settings are 100 120 220 or 240 Vac for 230 Vac operation use the 220 Vac setting See the diagram on the next page to verify or cha...

Page 17: ...ssembly 250 mAT fuse 250V 3 Rotate the line voltage selector until the correct voltage appears in the window 100 120 220 230 or 240 Vac 4 Replace the fuse holder assembly in the rear panel Install the correct fuse and verify that the correct line voltage appears in the window 1 Chapter 1 Quick Start If the Meter Does Not Turn On 15 ...

Page 18: ...Handle To adjust the position grasp the handle by the sides and pull outward Then rotate the handle to the desired position Bench top viewing positions Carrying Position Chapter 1 Quick Start To Adjust the Carrying Handle 16 ...

Page 19: ...ighest accuracy use the copper cable and connectors supplied by Hewlett Packard The conductors may require occasional cleaning to remove oxides Cleaning the conductors is described on page 271 W a r n i n g The connector body and cable shield are connected to earth ground RED HI CH1 BLACK LO HI CH2 GREEN WHITE LO Torque to 20 in lb maximum 1 Chapter 1 Quick Start To Make Input Connections 17 Agile...

Page 20: ...lding custom input cables Channel 1 HI LO DCV 4 WireΩ Source Source 2 WireΩ Source and Sense Source and Sense Thermistor Source and Sense Source and Sense Channel 2 HI LO DCV 4 WireΩ Sense Sense Thermocouple Earth Ground shell Chapter 1 Quick Start To Make Input Connections 18 ...

Page 21: ... mV range Independent NULL for each channel Channel 1 LO to Channel 2 LO isolated to 150 Vpeak Scan mode alternates between input channels every 3 seconds or every measurement whichever is longer RED BLACK CH1 CH2 GREEN WHITE DC Voltage DC Voltage DIFFERENCE RATIO VOLTAGE TOGGLES MEASUREMENT CHANNEL SCAN ALTERNATING MEASUREMENT CHANNELS 1 Chapter 1 Quick Start To Measure Voltage 19 ...

Page 22: ...e also Resistance Measurements on page 68 Resistance measurements use offset compensation Offset compensation can be disabled if desired see page 69 RED SOURCE CH1 GREEN CH2 SENSE WHITED 4 WIRE BLACK RED SOURCE BLACK GREEN 2 WIRE NOT CONNECTED WHITE OR 4 WIRE 2 WIRE Chapter 1 Quick Start To Measure Resistance 20 ...

Page 23: ...tor type 5 kΩ To Measure Temperature With RTDs 4 wire type α 00385 DIN IEC 751 or α 00391 R0 4 9 Ω to 2 1 kΩ RED CH1 BLACK GREEN OPEN WHITE RED SOURCE CH1 GREEN CH2 SENSE WHITE BLACK 1 Chapter 1 Quick Start To Measure Temperature With Thermistors 21 ...

Page 24: ...he internal thermistor as the temperature reference you should make a custom cable to connect the thermocouple wire directly to the input terminals see page 272 ISOTHERMAL BLOCK RED REFERENCE CH1 BLACK THERMISTOR GREEN CH2 WHITE EXTERNAL RED CH1 OPEN BLACK GREEN CH2 WHITE ICE BATH FIXED VALUE OR INTERNAL CH2 OR Chapter 1 Quick Start To Measure Temperature With Thermocouples 22 ...

Page 25: ...or ratio measurements an overload on either channel will give an overload indication OVLD For voltage measurements ranging is local to the selected channel This means that you can select the ranging method auto or manual for each channel independently When manually ranging the selected range is local to the active channel the meter remembers the range when you switch between channels Man annunciat...

Page 26: ...The number of digits is set to 61 2 digits at power on and after a remote interface reset The number of digits shown is dependent upon integration time and filter settings The meter will not allow you to show more digits than the practical measurement capability of the meter You can however reduce the number of digits shown Press the Shift key Selects 51 2 digits 1 PLC Selects 61 2 digits 10 PLC S...

Page 27: ...ed to the maximum number of digits the meter will display NPLC Filter Off Max Digits Shown Filter On Max Digits Shown 0 02 41 2 51 2 0 2 51 2 61 2 1 61 2 71 2 2 61 2 71 2 10 61 2 71 2 20 71 2 71 2 100 71 2 71 2 200 71 2 71 2 You can always show fewer digits than the maximum allowed the minimum number of digits shown is 41 2 Integration Time is local to the selected function This means that you can...

Page 28: ...30 mV This is the 100 mV range 51 2 digits are displayed 1 2 digit 7 digits 0 133 256 7 Ω This is the 1 ohm range 71 2 digits are displayed 1 2 digit O VLD mV This is an overload indication on the 1 mV range Negative sign or blank positive H 1 2 digit 0 or 1 D Numeric Digits E Exponent m k M F Measurement units Chapter 1 Quick Start Front Panel Display Formats 26 ...

Page 29: ...unting kit Any System II instrument of the same size can be rack mounted beside the 34420A meter Remove the carrying handle and the front and rear rubber bumpers before rack mounting the meter To remove the handle rotate it to the vertical position and pull the ends outward To remove the rubber bumper stretch a corner and then slide it off 1 Chapter 1 Quick Start To Rack Mount the Meter 27 ...

Page 30: ...ments side by side order lock link kit 5061 9694 and flange kit 5063 9212 To install one or two instruments in a sliding support shelf order shelf 5063 9255 and slide kit 1494 0015 for a single instrument also order filler panel 5002 3999 Chapter 1 Quick Start To Rack Mount the Meter 28 ...

Page 31: ...2 Front Panel Operation ...

Page 32: ...ar with this information please read chapter 1 Quick Start starting on page 11 This chapter does not give a detailed description of every front panel key or menu operation It does however give you a good overview of the front panel menu and the most common front panel operations See chapter 3 Features and Functions starting on page 53 for a complete discussion of the meter s capabilities and opera...

Page 33: ...s 3 RTD TYPE Sets the type of RTD in use 4 RTD Ro Sets the nominal 0 C value for the RTD in use 5 T C TYPE Selects the type of thermocouple in use 6 COLD JUNCT Sets the source of the temperature reference junction 7 JUNCT TEMP Allows direct entry of reference junction temperature C MATH MENU 1 STATS Ø 2 NULL VALUE Ø 3 SCALE GAIN Ø 4 SCALE OFST 1 STATS Recalls the values of minimum maximum standard...

Page 34: ... default 22 2 INTERFACE Selects either the GPIB or RS 232 remote interface 3 BAUD RATE Sets the baud rate for RS 232 operation 4 PARITY Selects even odd or no parity for RS 232 operation 5 LANGUAGE Selects interface language either SCPI or Keithley 181 G CALibration MENU 1 SECURED Ø 1 UNSECURED Ø 2 CALIBRATE Ø 3 CHART ZERO Ø 4 CHART GAIN Ø 5 INJECTED I Ø6 CAL COUNT Ø 7 MESSAGE 1 SECURED The meter ...

Page 35: ...ntal choices which you can view by moving left or right Menus Commands Parameters To turn on the menu press Shift Menu On Off To turn off the menu press Shift Menu On Off or press any of the function or math keys on the top row of front panel keys To execute a menu command press Auto Man To recall the last menu command that was executed press Shift Menu Recall To turn off the menu at any time with...

Page 36: ...Man Menu Enter to execute the command MIN VALUE The value you specified on the parameter level is too small for the selected command The minimum value allowed is displayed for you to edit MAX VALUE The value you specified on the parameter level is too large for the selected command The maximum value allowed is displayed for you to edit EXITING You will see this message if you turn off the menu by ...

Page 37: ...53 V With comma separator Without comma separator factory setting On Off Shift 1 Turn on the menu You enter the menu on the menus level The MEAS MENU is your first choice on this level A MEAS MENU 2 Move across to the SYS MENU choice on this level There are six menu group choices available on the menus level Each choice has a letter prefix for easy identification A B etc E SYS MENU 3 Move down to ...

Page 38: ... is ON for the COMMA command the comma setting is stored in non volatile memory and ON is the factory setting ON 6 Move across to the OFF choice There are two parameter choices for COMMA OFF Auto Man ENTER 7 Save the change and turn off the menu The meter beeps and displays a message to show that the change is now in effect You are then exited from the menu The meter will no longer show commas in ...

Page 39: ...and which was the last command used before you exited the menu in the Example 1 9 COMMA v 2 Move down to the COMMA parameter choices The first parameter choice is OFF the current setting from Example 1 OFF 3 Move across to the ON choice Set the parameter back to its original value ON Auto Man ENTER 4 Save the change and turn off the menu The meter beeps and displays a message to show that the chan...

Page 40: ... Connect the four wire short to the meter input On Off Shift 1 Turn on the menu You enter the menu on the menus level The MEAS MENU is your first choice on this level A MEAS MENU 2 Move across to the MATH MENU choice on this level There are six menu group choices available on this level C MATH MENU v 3 Move down to the commands level within the MATH MENU The STATS command is your first choice on t...

Page 41: ... edit and return to the commands level by pressing v v 6 Make the number negative The left most character on the display toggles between and 0 000 000 0 V 7 Move the flashing cursor over to edit the second digit Notice that the digit to the right of the decimal point is flashing 0 000 000 0 V 8 Increment the digit until 3 is displayed You decrement or increment each digit independently Neighboring...

Page 42: ... short the display will show a positive measurement in the approximate amount of the null value just entered The Null annunciator is on in the display Keep in mind that null is turned on and 0 03 volts is used as the null value for measurements To clear the null value press Null Hint You can use the menu recall feature to save steps when entering the null value First press Null on the front panel ...

Page 43: ...l 2 display Press Channel again to cancel Scan mode alternates between input channels every 3 seconds or every measurement whichever is longer If you are using the scan mode turn off all the input filters both digital and analog see page 55 RED DC Voltage BLACK GREEN DC Voltage WHITE TOGGLES MEASUREMENT CHANNEL SCAN ALTERNATING MEASUREMENT CHANNELS Channel 2 Channel 1 2 Chapter 2 Front Panel Opera...

Page 44: ...atio measurements an overload on either channel will give an overload indication OVLD For voltage measurements ranging is local to the selected channel This means that you can select the ranging method auto or manual for each channel independently When manually ranging the selected range is local to the active channel the meter remembers the range when you switch between channels Man annunciator i...

Page 45: ...mber of digits is set to 61 2 digits at power on and after a remote interface reset The number of digits shown is dependent upon integration time and filter settings The meter will not allow you to show more digits than the practical measurement capability of the meter You can however reduce the number of digits shown Fewer More Digits Digits Press the Shift key Selects 51 2 digits 1 PLC Selects 6...

Page 46: ...ted to the maximum number of digits the meter will display NPLC Digital Filter Off Max Digits Shown Digital Filter On Max Digits Shown 0 02 41 2 51 2 0 2 51 2 61 2 1 61 2 71 2 2 61 2 71 2 10 61 2 71 2 20 71 2 71 2 100 71 2 71 2 200 71 2 71 2 You can always select to show fewer digits than the maximum allowed the minimum number of digits shown is 41 2 Integration Time is local to the selected funct...

Page 47: ...e two wire ohms measurements short the ends of the test leads together and then press Null The first reading taken after you press Null is stored as the null value in the Null Register Any previously stored value is replaced with the new value After enabling null you can edit the stored null value by pressing Shift Menu Recall This takes you to the NULL VALUE command in the MATH MENU only if null ...

Page 48: ...u Recall This takes you to the STATS command in the MATH MENU only if stats is enabled Go down to the parameter level and then read the values by pressing or After reading the stored value pressing Shift Menu On Off returns to the measurement display and continues stats operations The stored values are cleared when you turn stats on turn off the power or perform either a remote interface reset or ...

Page 49: ...ternal Trigger The external trigger mode is also enabled by pressing Single It is like the single trigger mode except that you apply a trigger pulse to the rear panel Ext Trig terminal The meter is triggered on the negative edge of a TTL pulse The front panel Single key is disabled when in remote Enables single trigger and triggers the meter Toggles between autotrigger and reading hold sample annu...

Page 50: ...ter three consecutive readings are within the band The default band is 0 10 of reading After enabling reading hold you can choose a different band by pressing Shift Menu Recall This takes you to the READ HOLD command in the TRIG MENU only if reading hold is enabled Go down to the parameter level and then select a value 0 01 0 10 1 00 or 10 00 of reading The sensitivity band is stored in volatile m...

Page 51: ...al on Channel 2 is 12 Vdc the meter will autorange on the actual input or can be manually set Maximum voltage difference between Channel 1 LO and Channel 2 LO is 150 Vdc Null if used is independent for each channel An additional null of the difference can also be made If null is used on either input channel the Null annunciator will flash when the difference function is selected If you null the di...

Page 52: ...ct the single trigger mode Notice that the Trig annunciator turns on When reading memory is enabled readings are stored when you trigger the meter For this example single triggering is used to store readings You can also use auto triggering or reading hold On Off Shift 3 Turn on the menu A MEAS MENU 4 Move across to the SYS MENU choice on this level E SYS MENU v 5 Move down to a level to the RDGS ...

Page 53: ...O order When memory is full the Mem annunciator will turn off Readings are preserved until you re enable reading memory at another time turn off the power or perform a remote interface reset Single Single Single 8 Trigger the meter three times This stores three readings in memory Recall Shift 9 Use menu recall to retrieve the stored readings This takes you to the SAVED RDGS command in the SYS MENU...

Page 54: ...ief pause the reading number is removed and all reading digits are shown The stored readings are displayed with their units µ m k etc when appropriate For example Reading number 10 31607K 11 Units 10 316076 K 11 Move across to view the two remaining stored readings The readings are stored horizontally on the parameter level If you press when you first get to the parameter level you will see the la...

Page 55: ...3 Features and Functions ...

Page 56: ... page 98 Remote Interface Configuration page 101 Calibration page 107 Defaults Power On and Reset States page 112 Some knowledge of the front panel menu will be helpful before you read this chapter If you have not already read chapter 2 Front Panel Menu Operation starting on page 29 you may want to read it now Chapter 4 Remote Interface Reference starting on page 115 lists the syntax for the SCPI ...

Page 57: ...need Input Filters Two input filters are available a digital filter and an analog filter You can enable the digital filter the analog filter or both The digital filter may be used for any measurement type The analog filter is only available for thermocouple temperature measurements and voltage measurements on the 1 mV 10 mV or 100 mV ranges TURN FILTERS ON OR OFF DIGITAL Ø ANALOG Ø ANA DIG 3 Chapt...

Page 58: ...chapter 6 If you attempt to use the digital filter in remote operations be aware of the following special conditions The digital filter requires a number of readings to settle 10 50 or 100 The digital filter readings only occur when the meter is triggered to take a reading In remote operation a reading is only taken when requested For example if you have set the digital filter to MEDIUM 50 reading...

Page 59: ... time or channel is changed The filter count resets if a reading is outside a set range of the average The amount of input reading change required to reset the filter count is 1mV Range All Other Ranges FAST 400 ppm of range 100 ppm of range MEDIUM 700 ppm of range 300 ppm of range SLOW 2000 ppm of range 1000 ppm of range Analog Filter The analog filter is an 11 Hz two pole low pass filter Use thi...

Page 60: ...ntegration time is stored in volatile memory the meter selects 10 NPLC when power has been off or after an interface reset Only the integer number of power line cycles 1 2 10 20 100 or 200 NPLC provide normal mode line frequency noise rejection Integration time is related to the maximum number of digits the meter will display You can always choose to show fewer digits than the maximum allowed the ...

Page 61: ...20 100 200 MIN MAX FRES RES NPLC 0 02 0 2 1 2 10 20 100 200 MIN MAX TEMP NPLC 0 02 0 2 1 2 10 20 100 200 MIN MAX Integration time and resolution are related The CONFigure and MEASure commands can also set the integration time see page 129 Integration Time is local to the selected function This means that you can select the integration time for each function independently The meter remembers the in...

Page 62: ...eter by using either the digital filter or by using the statistics Stats mode of operation Measurement noise characteristics of the meter closely match theoretical gaussian noise distributions The graph on the next page shows typical input noise measurements for the 1 mV range with the low thermal shorting plug applied to the input terminals Other functions and ranges will exhibit similar noise re...

Page 63: ...time for the measurement function If possible use NPLC 200 If you use the CONFigure or MEASure commands refer to the table on page 129 Use the math operations AVERage to average the readings or average the readings in your program An example program that uses the math operations to average readings is shown on page 221 in Chapter 6 Do not use the digital filter to average readings see page 56 Equi...

Page 64: ...s displayed without disturbing the Integration Time settings by pressing the or keys see page 43 The number of digits is set to 61 2 digits at power on and after either a remote interface reset or preset The number of digits shown is dependent upon integration time and filter settings The meter will not allow you to show more digits than the practical measurement capability of the meter You can ho...

Page 65: ...s are displayed 1 2 digit 6 digits 0 216 569 mV This is the 1 mV range 61 2 digits are displayed 1 2 digit 5 digits 045 231 mV This is the 100 mV range 51 2 digits are displayed 1 2 digit 3 Chapter 3 Features and Functions General Measurement Configuration 63 ...

Page 66: ...ter than the present range can measure the meter gives an overload indication OVLD from the front panel or 9 90000000E 37 from the remote interface For ratio and difference measurements the specified range is independent for both Channel 1 and Channel 2 v Auto Man Front Panel operation Press a front panel RANGE key to set manual ranging and to up or down range Press the Auto Man key to return to a...

Page 67: ...t amplifier If signals large enough to overload the input amplifier are detected the display will read OVLD The comparators detect signals greater than 140 of the range setting If an overload occurs two solutions are possible Setting the meter to the next higher range will provide 10 times improvement in the overload signal handling capability For example if you are measuring on the 1 mV range and...

Page 68: ... 1 LO and Channel 2 LO is 150 V For either channel the maximum non destructive input is 150 V If you enable input filters the filters are active for both input channels Switching between the channels will reset the digital filter reading count see page 57 Channel Front Panel operation Toggle the input channel by pressing the Channel key on the front panel The CH1 or CH2 annunciator will light in t...

Page 69: ...oltage Ch 2 Null Null Shift Ch1 Ch2 Ratio measurements First set the range and null value for each input channel Then select ratio measurements Ratio Ch 1 voltage Ch 1 Null Ch 2 voltage Ch 2 Null Remote operation use the following commands to measure or configure a difference or ratio measurement Set each channel to the appropriate range and null conditions using SENSe1 SENSe2 VOLTage DC RANGE ran...

Page 70: ...The test current sourced by the meter depends upon the range and conditions as shown below Range Test current 2 wire or 4 wire measurements 4 wire measurements Low Power Voltage Limited 1Ω 10 mA 10 mA Not Available 10 Ω 10 mA 10 mA 1 mA 100 Ω 10 mA 1 mA 100 µA 1 kΩ 1 mA 100 µA Not Available 10 kΩ 100 µA 10 µA Not Available 100 kΩ 10 µA 5 µA Not Available 1 MΩ 5 µA 5 µA Not Available Offset Compens...

Page 71: ...and to change the state of offset compensation SENSe FRESistance OCOMpensated OFF ON RESistance OCOMpensated OFF ON Low Power Measurements Low Power measurements use a reduced output measurement current to limit the power dissipation in the circuit being measured Low Power measurements apply only to 4 wire ohms measurements When the low power measurement mode is enabled the LP annunciator is on in...

Page 72: ...r 10 Ω or 100 Ω The open circuit voltage can be limited to 20 mV 100 mV or 500 mV Setting the Low Power measurement mode will cancel the Voltage Limited mode Front panel operation Enable or disable the voltage limit under the 5 LOW VOLT Ω command in the MEASure menu Set the voltage limit under the 6 LoV LIMIT Ω command in the MEASure menu Remote operation the following command enables or disable t...

Page 73: ...tegory RTD s R0 4 9 Ω to 2 1 kΩ Thermistor Thermocouples α 0 00385 DIN IEC 751 α 0 00391 5k Ω B E J K N R S T Once you set the measurement units probe type and transducer type the setting is stored in non volatile memory This makes the last probe type used the default probe type Measurement Units The meter can report temperature in C Celsius F Fahrenheit or K Kelvins The measurement units set are ...

Page 74: ...EMPerature FRTD 85 91 1 resolution MEASure TEMPerature FRTD 85 91 1 resolution SENSe FUNCtion TEMPerature SENSe TEMPerature TRANsducer TYPE FRTD SENSe TEMPerature TRANsducer FRTD TYPE 85 91 SENSe TEMPerature TRANsducer FRTD RESistance value Thermistor Measurements Only the 5 kΩ thermistor type is supported Thermistor connections are shown on page 21 The thermistor must be connected to the Channel ...

Page 75: ...temperature measurements Front Panel operation Set T C as the probe type under the 1 PROBE TYPE command in the TEMPerature menu Select the thermocouple type under the 4 T C TYPE command in the Temperature menu Set the reference junction temperature source under the 5 COLD JUNCT command in the TEMPerature menu If you used a FIXed reference junction temperature set the reference temperature under th...

Page 76: ...Scale Shift Stats Front Panel operation Set the values of gain and offset in the MATH menu Enable scaling by pressing the scale key The Stats annunciator will light in the display Remote operation the math operations and registers are controlled using commands within the CALCulate command subsystem First select the math operation you want to use CALCulate FUNCtion SCALe Then set the values for gai...

Page 77: ...face reset or preset When enabled the following statistics are available MIN minimum reading MAX maximum reading AVER arithmetic average of all readings STD DEV standard deviation of all readings PEAK PEAK peak to peak value of minimum and maximum COUNT the total number of readings Front Panel operation Enable the statistics by pressing the Stats key Read the statistics gathered in the MATH menu u...

Page 78: ...upply another trigger to continue taking measurements and collecting statistics Measurements are not taken while reading the results If you are interested in the statistics on a number of readings but not the readings themselves you can use the following command DATA FEED RDG_STORE The null value parameter in the command tells the meter not to store the individual readings The meter does however a...

Page 79: ...ll value is stored in the meter s Null Register There are two ways you can specify the null value First you can enter a specific number into the register from the front panel menu or from the remote interface Any previously stored value is replaced with the new value If you are operating the meter from the front panel entering a null value also turns on the null function The second way to enter th...

Page 80: ...ot flash Remote interface operation You can use the following commands to make null measurements Null must be enabled before you can store a value in the Null Register SENSe1 SENSe2 VOLTage DC NULL OFF ON NULL value MIN MAX SENSe FRESistance RESistance NULL OFF ON NULL value MIN MAX TEMPerature NULL OFF ON NULL value MIN MAX To enable null and set a null value 0 10 for the 2 wire resistance functi...

Page 81: ...capture and display a new value only after three consecutive readings are within the band Select one of these values 0 01 0 10 default 1 00 or 10 0 of reading For example assume that the 1 00 band is selected and a 5 volt signal is applied to the meter If three consecutive readings are between 4 95 volts and 5 05 volts the meter will beep and display a new reading The sensitivity band is stored in...

Page 82: ... the present configuration See also To Trigger the Meter on page 47 Press Shift Auto Hold to return the meter to auto triggering Triggering the meter from the remote interface is a multi step process that offers triggering flexibility First you must configure the meter for the measurement by selecting the function range integration time etc Then you must specify the source from which the meter wil...

Page 83: ...EASure READ INITiate Trigger Source TRIGger SOURce IMMediate TRIGger SOURce EXTernal TRIGger SOURce BUS front panel Single key Trigger Delay TRIGger DELay Sample Annunciator Trigger Count 1 Triggering the meter is a multi step process No Yes Yes No 3 Chapter 3 Features and Functions Triggering 81 ...

Page 84: ...g terminal or an immediate internal trigger See Triggering on page 80 for more information Autotriggering In the autotrigger mode front panel only the meter continuously takes readings at the fastest rate possible for the present configuration This is the power on trigger source for front panel operation Single Triggering In the single trigger mode front panel only you can manually trigger the met...

Page 85: ...nored error is not reported After the reading in progress is complete the stored trigger satisfies the trigger source and then the trigger is issued Front panel operation The external trigger mode is like the single trigger mode except that you apply the trigger to the Ext Trig terminal Pressing Single to enable the single trigger mode also enables the external trigger mode The Trig annunciator tu...

Page 86: ...gger mode is available only from the remote interface This mode is similar to the single trigger mode from the front panel but you trigger the meter by sending a bus trigger command To select the bus trigger source send the following command TRIGger SOURce BUS To trigger the meter from the remote interface HP IB or RS 232 send the TRG trigger command The TRG command will not be accepted unless the...

Page 87: ...ny of the following commands from the remote interface MEASure READ INITiate Halting a Measurement in Progress You can send a device clear at any time to halt a measurement in progress and place the meter in the idle state The following statement shows how to send a device clear from a Hewlett Packard controller if you are using the HP IB interface See also page 187 CLEAR 722 device clear For oper...

Page 88: ...nly one trigger before returning to the idle trigger state You can however instruct the meter to accept multiple triggers This feature is available only from the remote interface If you set the trigger count and then go to local front panel the meter ignores the trigger count setting when you return to remote the trigger count returns to the value you selected The selected number of triggers is st...

Page 89: ... an automatic trigger delay when power has been off or after a remote interface reset The CONFigure and MEASure commands set the trigger delay to automatic If you specify a delay other than automatic that same delay is used for all functions and ranges If you have configured the meter to take more than one reading per trigger sample count 1 the specified trigger delay is inserted between the trigg...

Page 90: ...the automatic trigger delay select the parameter level of the TRIG DELAY command Move the flashing cursor to the units location on the right side of the display Press until AUTO DELAY is reached then press Enter AUTO DELAY Remote operation You can use the following command to set the trigger delay TRIGger DELay seconds MIN MAX You can use the following command to set an automatic trigger delay TRI...

Page 91: ...ay 1 mV 10 mV to 120 V 15 ms 1 0 ms 15 ms 1 5 ms Resistance 2 wire and 4 wire Range NPLC 1 Trigger Delay NPLC 1 Trigger Delay 1 Ω 10 Ω 100 Ω 1 kΩ 10 kΩ 100 kΩ 1 MΩ 1 0 ms 1 0 ms 1 0 ms 1 0 ms 1 0 ms 4 ms 40 ms 1 5 ms 1 5 ms 1 5 ms 1 5 ms 1 5 ms 6 ms 60 ms Temperature NPLC 1 Trigger Delay NPLC 1 Trigger Delay RTD THERmistor ThermoCouple 1 0 ms 1 0 ms 1 0 ms 1 5 ms 1 5 ms 1 5 ms 3 Chapter 3 Features...

Page 92: ...and also reading hold After you have enabled reading memory you can change the function or input channel Be aware however that the function labels and channel labels V OHM etc are not stored with the reading Readings taken while reading memory is enabled are stored in volatile memory the meter clears the stored readings when reading memory is turned on again when power has been off after a self te...

Page 93: ...ading memory to quickly go to the Saved Readings command Reading memory is automatically turned off when you go to the parameter level in the menu to recall the readings Remote interface operation The INITiate command uses reading memory to store readings prior to a FETCh command You can query the number of stored readings in memory by sending the DATA POINts command from the remote interface 3 Ch...

Page 94: ...tored until you remove errors from the queue If no errors have occurred and you read the error queue the meter responds with 0 No error The error queue is cleared when power has been off or after a CLS clear status command has been executed Front panel operation read the errors under the 3 ERROR command in the SYStem menu If the ERROR annunciator is on press Shift Menu Recall to read the errors st...

Page 95: ... test is successful PASS is displayed on the front panel If the self test fails FAIL is displayed and the ERROR annunciator turns on See the 34420A Service Guide for instructions on returning the meter to Hewlett Packard for service Front Panel operation You can perform some of the tests individually or you can perform all tests together at once Scroll through the parameters under the 4 TEST comma...

Page 96: ...e truncated Commas periods and semicolons share a display space with the preceding character and are not considered individual characters When a message is displayed readings are not sent to the display Sending a message to the display from the remote interface overrides the display state this means that you can display a message even if the display is turned off Front panel operation set the disp...

Page 97: ...e SYStem menu Firmware Revision Query The meter has three microprocessors for control of various internal systems You can query the meter to determine which revision of firmware is installed for each microprocessor The meter returns three numbers The first number is the firmware revision number for the measurement processor the second is for the input output processor and the third is for the fron...

Page 98: ...eter is in compliance by sending a command from the remote interface You cannot query the SCPI version from the front panel The following command returns the SCPI version SYSTem VERSion Returns a string in the form YYYY V where the Y s represent the year of the version and the V represents a version number for that year for example 1994 0 Chapter 3 Features and Functions System Related Operations ...

Page 99: ...d switching devices External Trigger Terminal You can trigger the meter by applying a low true pulse to the rear panel Ext Trig external trigger terminal To use this terminal from the remote interface you must select the external trigger source TRIGger SOURce EXTernal You can use a simple switch to generate an external trigger using the Ext Trig input as shown below Output Approximately 2µs Input ...

Page 100: ...ing includes the results of measurement unit conversion filtering null and any math operation performed on the measurement The chart output state including the span and null values is stored in non volatile memory span cannot have a negative value The chart output has a voltage rollover to prevent the loss of data see page 100 Examples See page 38 for a menu procedure to enter a number 1 To set th...

Page 101: ...art offset under the 7 CHART NULL command in the SYStem menu You can also press Shift Null Chart Null to null the chart output voltage based upon the displayed reading This action places a null value in the Chart Offset register Pressing Shift Menu Recall will take you to the 7 CHART NULL command where you can manually edit the null value Remote operation use the following commands to enable and s...

Page 102: ...ffectively shifting the chart range and center values By counting the steps and noting their direction the actual measurement values can be deduced Example The chart output voltage is set to 3 V to correspond to an input temperature range of 5 C to 45 C with the 0 V output at 25 C span 6 66 and chart null 25 If the actual measured temperatures ranged from 20 C to 100 C a strip chart recorder might...

Page 103: ... you must select a unique address for the meter The HP IB address is displayed when you turn on the meter If you select the RS 232 interface you must set the baud rate and parity for the meter RS 232 is displayed when you turn on the meter If you select the RS 232 interface and then set the HP IB address to the talk only address 31 the meter will send readings over the RS 232 interface when in the...

Page 104: ...rinter without being addressed by a bus controller Address 31 is not a valid address if you are operating the multimeter from the HP IB interface with a bus controller If you select the RS 232 interface and then set the HP IB address to the talk only address 31 the meter will send readings over the RS 232 interface when in the local mode Your HP IB bus controller has its own address Be sure to avo...

Page 105: ...volatile memory and does not change when power has been off or after a remote interface reset Front Panel operation set the baud rate under the 3 BAUD RATE command in the I O menu See also To Set the Baud Rate on page 190 Remote operation use the following commands to set the baud rate SYStem COMMunicate SERial BAUD baud If you change the baud rate over the remote interface you may lose control of...

Page 106: ...s The parity selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset Front Panel operation set the parity under the 4 PARITY command in the I O menu See also To Set the Parity on page 191 Remote operation use the following commands to set the parity SYStem COMMunicate SERial PARity EVEN ODD NONE If you change the parity over the remo...

Page 107: ...or after a remote interface reset There are certain restrictions to be aware of when you are selecting the interface language see also Remote Interface Selection on page 101 The Keithley 181 language is not supported on the RS 232 interface Front Panel operation set the programming language under the 5 LANGUAGE command in the I O menu See also To Select The Programming Language on page 192 Remote ...

Page 108: ...connections Additional information about the interface is given on page 176 Pin Number Input Output Description 1 2 3 4 5 6 9 Input Output Output Input Receive Data RxD Transmit Data RxD Data Terminal Ready DTR Signal Ground SG Data Set Ready DSR If you are using the RS 232 interface for connection to a printer you may wish to use the Talk Only mode This mode is enabled by setting the HP IB addres...

Page 109: ... characters as shown below The first character must be a letter but the remaining characters can be letters or numbers You do not have to use all 11 characters but the first character must always be a letter A _ _ _ _ _ _ _ _ _ _ _ 11 characters To secure the meter from the remote interface so that it can be unsecured from the front panel use the eight character format shown below The first two ch...

Page 110: ...ommand is hidden if the meter is secured To unsecure the meter select the parameter level of the SECURED command enter the security code then press Enter 000000 CODE When you go to the commands level in the CAL MENU again you will notice that the meter is unsecured Notice also that the 2 CALIBRATE command is no longer hidden and you can perform a calibration 1 UNSECURED Remote operation use the fo...

Page 111: ... when you go into the CAL MENU To secure the meter select the parameter level of the UNSECURED command enter the security code then press Menu Enter 000000 CODE When you go to the commands level in the CAL MENU again you will notice that the meter is secured Notice also that the 2 CALIBRATE command is now hidden and you cannot perform a calibration 1 UNSECURED Remote interface operation CALibratio...

Page 112: ...or example CAL SEC STAT OFF HP034420 CAL SEC CODE HP010495 unsecure with old code enter new code Calibration Count You can determine the number of times that your meter has been calibrated Since the value increments by one for each calibration point a complete calibration increases the value by several counts The calibration count is stored in non volatile memory and does not change when power has...

Page 113: ...calibration message may contain up to 40 characters The meter can display up to 11 characters of the message on the front panel any additional characters are truncated The calibration message is stored in non volatile memory and does not change when power has been off or after a remote interface reset Front Panel operation read the calibration message if any under the 4 MESSAGE command in the CALi...

Page 114: ...er Off Off Offset Compensation On Off N Samples 1 1 Display On or Off On On Trigger Autotrigger Autotrigger Math Off Off Readings Hold Off Off Readings Store Off Off Trigger Delay Auto Auto Integration Time NPLC 3 10 plc 10 plc Null 3 Off Off Range 3 Autorange Autorange 1 Remote defaults are used following reset RST preset SYSTem PRESet CONFigure or MEASure commands 2 You should ensure the digital...

Page 115: ...ory settings and their factory defaults Setting Factory Default Digital Filter1 MEDium 50 rdgs Digital Filter Precharge On Low Power Ω Off Low Volt Ω Off LoV Limit Ω 20 mV Probe Type RTD RTD Type α 00385 RTD R0 100 Ω Temperature Units C Chart Out Off Chart Span 1 mV Chart Offset 0 00 V Comma On 1 The digital filter is ON following a Front Panel PRESET The digital filter is OFF following a Remote I...

Page 116: ... Range Integration Time Integration Time Integration Time Number of Digits Number of Digits Number of Digits Math Stats or Scale Digital Filter On Off Analog Filter On Off 2 Trigger Readings Hold Readings Store 1 The meter may change the set resistance measurement range when voltage limited measurements are enabled 2 Analog filter available for voltage and thermocouple measurements on the 1 mV 10 ...

Page 117: ...4 Remote Interface Reference ...

Page 118: ...odel page 159 Status Reporting Commands page 171 Calibration Commands page 174 RS 232 Interface Configuration page 176 RS 232 Interface Commands page 182 An Introduction to the SCPI Language page 183 Input Message Terminators page 186 Output Data Formats page 186 Using Device Clear to Halt Measurements page 187 TALK ONLY for Printers page 187 To Set the HP IB Address page 188 To Select the Remote ...

Page 119: ...s are used for SCPI command syntax Square brackets indicate optional keywords or parameters Braces enclose a list of parameters separated with a vertical bar use only one of the values Triangle brackets indicate that you must substitute a value for the enclosed parameter The actual command string you send to the meter should not include any of the conventions indicated above First time SCPI users ...

Page 120: ...Ction VOLTage DC FUNCtion VOLTage DC RATio FUNCtion VOLTage DC DIFFerence FUNCtion SENSe SENSe1 SENSe2 VOLTage DC RANGe range MIN MAX VOLTage DC RANGe MIN MAX VOLTage DC RANGe AUTO OFF ON VOLTage DC RANGe AUTO SENSe SENSe1 SENSe2 VOLTage DC RESolution resolution MIN MAX VOLTage DC RESolution MIN MAX SENSe SENSe1 SENSe2 VOLTage DC NPLCycles 0 02 0 2 1 2 10 20 100 200 MIN MAX VOLTage DC NPLCycles MI...

Page 121: ...Ge MIN MAX RANGe AUTO OFF ON RANGe AUTO SENSe FRESistance RESistance RESolution resolution MIN MAX RESolution MIN MAX SENSe FRESistance RESistance NPLCycles 0 02 0 2 1 2 10 20 100 200 MIN MAX NPLCycles MIN MAX SENSe FRESistance RESistance NULL STATe OFF ON NULL STATe NULL VALue value MIN MAX NULL VALue SENSe FRESistance RESistance OCOMpensated OFF ON OCOMpensated SENSe FRESistance POWer LIMit STAT...

Page 122: ...e MIN MAX TEMPerature TRANsducer TCouple RJUNction MIN MAX TEMPerature TRANsducer TCouple RJUNction TYPE FIX INT THER TEMPerature TRANsducer TCouple RJUNction TYPE SENSe TEMPerature TRANsducer FRTD TYPE 85 91 TEMPerature TRANsducer FRTD TYPE TEMPerature TRANsducer FRTD RESistance REFerence value TEMPerature TRANsducer FRTD RESistance REFerence SENSe TEMPerature NULL STATe OFF ON TEMPerature NULL S...

Page 123: ...ECharge AUTO ROUTe TERMinals FRONt FRONt1 FRONt2 ROUTe TERMinals Math Operation Commands CALCulate FUNCtion AVERage SCALe FUNCtion STATe OFF ON STATe CALCulate AVERage MINimum AVERage MAXimum AVERage AVERage AVERage COUNt AVERage PTPeak AVERage SDEViation CALCulate SCALe GAIN gain SCALe GAIN SCALe OFFSet offset SCALe OFFSet DATA FEED RDG_STORE CALC FEED RDG_STORE POINts 4 Chapter 4 Remote Interfac...

Page 124: ...SAMPle COUNt value MIN MAX COUNt MIN MAX Chart Output Commands OUTPut STATe OFF ON STATe REFerence OFFSet number MIN MAX REFerence OFFSet MIN MAX REFerence OFFSet NULL REFerence SPAN number MIN MAX REFerence SPAN MIN MAX REFerence GAIN REFerence VALue value MIN MAX System Related Commands FETCh READ DATA FEED RDG_STORE CALC FEED RDG_STORE POINts Chapter 4 Remote Interface Reference Command Summary...

Page 125: ...us Reporting Commands SYSTem ERRor STATus OPERation CONDition OPERation ENABle enable value OPERation ENABle OPERation EVENt QUEStionable CONDition QUEStionable ENABle enable value QUEStionable ENABle QUEStionable EVENt STATus PRESet CLS STB ESE enable value PSC 0 1 ESE PSC ESR SRE enable value SRE OPC OPC 4 Chapter 4 Remote Interface Reference Command Summary 123 ...

Page 126: ...ion STRing quoted string STRing CALibration VALue value VALue Remote Interface Commands SYSTem INTerface HPIB RS232 INTerface SYSTem COMMunicate SERial BAUD baud COMMunicate SERial BAUD COMMunicate SERial PARity EVEN ODD NONE COMMunicate SERial PARity SYSTem LANGuage SCPI 181 LOCal REMote RWLock L1X SCPI language L2X 181 language Chapter 4 Remote Interface Reference Command Summary 124 ...

Page 127: ...IEEE 488 2 Common Commands CLS ESE enable value ESE ESR IDN OPC OPC PSC 0 1 PSC RST SRE enable value SRE STB TRG TST WAI 4 Chapter 4 Remote Interface Reference Command Summary 125 ...

Page 128: ...red data into your bus controller The MEASure and CONFigure commands provide the most straight forward method to program the meter for measurements You can select the measurement function range and resolution all in one command The meter uses defaults for other measurement parameters Integration time range and resolution are local to the function or channel used in the MEASure and CONFigure comman...

Page 129: ...cific Offset Compensated Ω SOURce FRESistance OCOMPensated Off Voltage Limited Ω SOURce FRESistance VOLTage LIMit Last value set Low Power Ω SOURce FRESistance POWer LIMit Last value set Temperature Specific Transducer SENSe TEMPerature TRANsducer Last probe set Probe Type SENSe TEMPerature TRANsducer Last type set RTD type and resistance SENSe TEMPerature TRANsducer Last type set The MEASure and ...

Page 130: ...g the CONFigure Command For a little more programming flexibility use the CONFigure command When you execute the command the meter sets the defaults for the requested configuration like the MEASure command However the measurement is not automatically started and you can change measurement parameters before making measurements This allows you to incrementally change the meter s configuration from t...

Page 131: ...eter The resolution parameter can be set to any number but the resulting integration time NPLC is one of the following resolution Parameter Integration Time NPLC 0 0001 x Range 0 02 0 00001 x Range 2 0 000003 x Range 1 0 0000022 x Range 2 0 000001 x Range 10 0 0000008 x Range 20 0 0000003 x Range 100 0 00000022 x Range 200 Specify the resolution in the same units as the measurement function not in...

Page 132: ...ter s internal memory when using the READ command Sending the READ command is like sending the INITiate command followed immediately by the FETCh command except readings are not buffered internally C a u t i o n If you send two query commands without reading the response from the first and then attempt to read the second response you may receive some data from the first response followed by the co...

Page 133: ...ings can be stored Readings are stored in memory until you are able to retrieve them Use the FETCh command to transfer the readings from the meter s internal memory to the meter s output buffer where you can read them into your bus controller Configure the meter using the SENSe commands For voltage measurements on two channels you can configure each channel independently by specifying either SENSe...

Page 134: ...igger count sample count trigger delay etc All measurement parameters except function range and resolution are preset for you automatically see the table on page 127 CONFigure Example 1 The following program segment shows how to use the READ command with CONFigure to make an externally triggered measurement The program configures the meter for dc voltage measurements CONFigure does not place the m...

Page 135: ...ry error is generated After you execute an INITiate command no further commands are accepted until the measurement sequence is completed However if you select TRIGger SOURce BUS the meter will accept the TRG command bus trigger or an IEEE 488 Group Execute Trigger message You can stop a measurement started with an INITiate command by sending a device clear see page 187 CONFigure Example 3 The foll...

Page 136: ...range to use the resolution parameter For voltage measurements you can also specify the input channel The parameter channel can be set to FRONt1 FRONt2 1 or 2 In the command the channel must be preceded by the symbol and enclosed in parenthesis MEASure VOLTage DC range AUTO MIN MAX DEF resolution MIN MAX DEF channel This command presets and makes a voltage measurement with the specified range reso...

Page 137: ...solution MIN MAX DEF This command presets and configures the meter for temperature measurements using the specified probe type and resolution The reading is sent to the output buffer DEF defaults to the last probe type set CONFigure VOLTage DC range AUTO MIN MAX DEF resolution MIN MAX DEF channel This command presets and configures the meter for dc voltage measurements with the specified range res...

Page 138: ... DEF This command presets and configures the meter for 2 wire or 4 wire ohms measurements with the specified range and resolution This command does not initiate the measurement CONFigure TEMPerature TC DEF B E J K N R S T DEF 1 resolution MIN MAX DEF THER DEF DEF 1 resolution MIN MAX DEF FRTD DEF 85 91 DEF 1 resolution MIN MAX DEF This command presets and configures the meter for temperature measu...

Page 139: ...e 4 wire ohms VOLTage DC DIFFerence TEMPerature SENSe FUNCtion This command queries the measurement function and return a quoted string SENSe1 SENSe2 VOLTage DC RANGe range MIN MAX SENSe FRESistance RESistance RANGe range MIN MAX This command sets the range for the function specified MIN selects the lowest range MAX selects the highest range volatile memory SENSe1 SENSe2 VOLTage DC RANGe MIN MAX S...

Page 140: ...ESolution resolution MIN MAX SENSe FRESistance RESistance RESolution resolution MIN MAX This command sets the resolution for the specified function Specify the resolution in the same units as the measurement function not in number of digits MIN selects the smallest value accepted which gives the most resolution MAX selects the largest value accepted which gives the least resolution volatile memory...

Page 141: ...d selects the integration time in number of power line cycles for the present function the default is 10 PLC MIN 0 02 MAX 200 volatile memory SENSe1 SENSe2 VOLTage DC NPLCycles MIN MAX SENSe FRESistance RESistance NPLCycles MIN MAX SENSe TEMPerature NPLCycles MIN MAX This command queries the integration time for the selected function 4 Chapter 4 Remote Interface Reference Setting the Function Rang...

Page 142: ...e RANGe 10 Channel 1 range setting SENSe2 VOLTage RANGe 10 Channel 2 range setting For increased flexibility and to take advantage of the independant null and range settings for each input channel you can set each input channel as desired and switch between the input channels using the ROUTe TERMinals command For example SENSe1 VOLTage RANGe 10 Channel 1 range 10 V SENSe2 VOLTage RANGe 1 Channel 2...

Page 143: ...tance measurements SENSe FRESistance POWer LIMit STATe OFF ON POWer LIMit STATe This command enables or disable the 4 wire low power resistance mode see page 69 SENSe FRESistance VOLTage LIMit STATe OFF ON VOLTage LIMit STATe VOLTage LIMit VALue value MIN MAX VOLTage LIMit VALue MIN MAX This command enables or disables the 4 wire voltage limited resistance mode see page 70 The voltage limit value ...

Page 144: ...type and resolution The reading is sent to the output buffer Set the measurement probe type in the first parameter either TC thermocouple THER Thermistor or FRTD four wire RTD The DEF default option sets the last probe type used Set the thermocouple or RTD type in the second parameter Set to DEF for thermistors The optional parameter 1 is a place holder to allow you to set the resolution CONFigure...

Page 145: ...erature for thermocouple measurements when using a fixed temperature reference MIN sets 0 C MAX sets 55 C SENSe TEMPerature TRANsducer TCouple RJUNction MIN MAX This command queries for the reference junction temperature if set when using a fixed temperature reference MIN returns 0 C MAX returns 55 C SENSe TEMPerature TRANsducer TCouple RJUNction TYPE FIX INT THER This command sets the reference j...

Page 146: ...FRTD RESistance REFerence value This command sets the four wire RTD R0 value The value is in the range of 4 9 Ω to 2 1 kΩ SENSe TEMPerature TRANsducer FRTD RESistance REFerence This command queries for the RTD R0 value being used UNIT TEMPerature C CEL F FAR K This command sets the measurement and reporting units for temperature measurements UNIT TEMPerature This command queries the temperature me...

Page 147: ...ed before the null value can be set The null value set must be within 1 2 MΩ Null is common to both 2 wire and 4 wire resistance measurements that is enabling null on 4 wire ohms measurements also enables null on 2 wire ohms measurements SENSe TEMPerature NULL STATe OFF ON NULL STATe NULL VALue value MIN MAX NULL VALue These commands enable or disable the null state for temperature measurements Nu...

Page 148: ...ly enough triggers to fill up the average before the filter will settle If your measurement requires averaging readings use the math operations Stats instead of the digital filter see page 148 The digital filter average may reset based upon the measurement value see page 57 You must use the STATus OPERation CONDition register to determine if the filter is settled with each reading taken The analog...

Page 149: ... set the averaging for the digital filter and query the digital filter setting SLOW sets a 100 reading average MEDium sets a 50 reading average and FAST sets a 10 reading average INPut FILTer DIGital PRECharge OFF ON DIGital PRECharge These commands enable or disable the digital filter precharge and query the digital filter precharge setting Disabling the digital filter precharge prevents the filt...

Page 150: ...u disable it change functions turn off the power or perform a remote interface reset CALCulate FUNCtion AVERage SCALe This command selects the main math function Only one function can be enabled at a time volatile memory CALCulate FUNCtion This command queries the present math function Returns SCAL or AVER CALCulate STATe OFF ON This command disables or enables the selected math function volatile ...

Page 151: ...ars the value when math is turned on when power has been off or after a remote interface reset volatile memory CALCulate AVERage COUNt This command returns the number of readings taken since math average was enabled The meter clears the value when math is turned on when power has been off or after a remote interface reset volatile memory CALCulate AVERage PTPeak This command returns the peak to pe...

Page 152: ...rated if you attempt to transfer readings to the output buffer using the FETCh command DATA FEED This command queries the reading memory state Returns CALC or DATA POINts This comand queries the number of readings in memory Scale operation commands You must have set CALC FUNC SCAL and CALC ON to use these commands CALCulate SCALe GAIN gain This comand sets the slope of the readings scale according...

Page 153: ...ffers triggering flexibility First you must configure the meter for the measurement by selecting the function range resolution etc Then you must specify the source from which the meter will accept the trigger The meter will accept a software bus trigger from the remote interface a hardware trigger from the rear panel Ext Trig external trigger terminal or an immediate internal trigger Then you must...

Page 154: ...Sure READ INITiate Trigger Source TRIGger SOURce IMMediate TRIGger SOURce EXTernal TRIGger SOURce BUS front panel Single key Trigger Delay TRIGger DELay Sample Annunciator Trigger Count 1 Triggering the meter is a multi step process No Yes Yes No Chapter 4 Remote Interface Reference Triggering 152 ...

Page 155: ... used primarily for remote interface operation From the front panel the meter is always in the wait for trigger state and will accept triggers at any time unless a measurement is already in progress You can place the meter in the wait for trigger state by executing any of the following commands from the remote interface MEASure READ INITiate The meter requires approximately 20 ms of set up time af...

Page 156: ...tate to the wait for trigger state Measurements will begin when the specified trigger conditions are satisfied following the receipt of the READ command Readings are sent immediately to the output buffer TRIGger SOURce BUS IMMediate EXTernal This command selects the source from which the meter will accept a trigger The meter will accept a software bus trigger an immediate internal trigger this is ...

Page 157: ...ic trigger delay setting Returns 0 OFF or 1 ON SAMPle COUNt value MIN MAX This command sets the number of readings samples the meter takes per trigger Select from 1 to 50 000 readings per trigger MIN 1 and MAX 50 000 volatile memory SAMPle COUNt MIN MAX This command queries the sample count TRIGger COUNt value MIN MAX INFinity This command sets the number of triggers the meter will accept before r...

Page 158: ...MIN sets 1 0E9 V and MAX sets 1 0E9 V The NULL form of this command makes the next measurement value the null value OUTPut REFerence SPAN number MIN MAX REFerence SPAN MIN MAX REFerence GAIN These commands set or query the span value The span can be set in the range of 5E 9 to 1 0E9 MIN sets 5E 9 and MAX sets 1 0E9 The GAIN query returns the reciprocal of the span value OUTPut REFerence VALue valu...

Page 159: ...e receipt of the READ command Readings are sent immediately to the output buffer DISPlay OFF ON This command turns the front panel display off or on volatile memory DISPlay This command queries the front panel display setting Returns 0 OFF or 1 ON DISPlay TEXT quoted string This command displays a message on the front panel The meter will display up to 11 characters in a message any additional cha...

Page 160: ...s the meter to determine the present SCPI version Returns 1994 0 RST This command resets the meter to its power on configuration TST This command performs a complete self test of the meter Returns 0 if the self test is successful or 1 if the test fails IDN This command reads the meter s identification string be sure to dimension a string variable with at least 40 characters Chapter 4 Remote Interf...

Page 161: ... that register such as ESR or STAT QUES EVEN or by sending the CLS clear status command A reset RST or device clear will not clear bits in event registers Querying an event register returns a decimal value which corresponds to the binary weighted sum of all bits set in the register What is an Enable Register An enable register defines which bits in the corresponding event register are logically OR...

Page 162: ...SCPI Status System See page 169 for information on the use of this bit Chapter 4 Remote Interface Reference The SCPI Status Model 160 ...

Page 163: ... Register Bit Decimal Value Definition 0 Not Used 1 Always set to 0 1 Not Used 2 Always set to 0 2 Not Used 4 Always set to 0 3 Questionable Data 8 One or more bits are set in the Questionable Data register bits must be enabled in the enable register 4 Message Available 16 Data is available in the meter output buffer 5 Standard Event 32 One or more bits are set in the Standard Event register bits ...

Page 164: ... bus controller may then poll the instruments on the bus to identify which one requested service the one with bit 6 set in its status byte The request service bit is only cleared by reading the status byte using an IEEE 488 serial poll or by reading the event register whose summary bit is causing the service request To read the status byte summary register send the IEEE 488 serial poll message Que...

Page 165: ...able masks Send the OPC operation complete query command and enter the result to assure synchronization Enable your bus controller s IEEE 488 SRQ interrupt To Determine When a Command Sequence is Completed Either Send the OPC operation complete query command and enter the result to assure synchronization Or to prevent holding the interface bus for commands that take longer to execute such as CALib...

Page 166: ... s internal memory when using INITiate Sending the FETCh command transfers readings stored in internal memory by the INITiate command to the meter s output buffer Therefore the MAV bit can only be set after all measurements have been completed Using OPC to Signal When Data is in the Output Buffer Generally it is best to use the operation complete bit bit 0 in the standard event register to signal ...

Page 167: ... However no error message is recorded in the meter s error queue Read the error queue using SYSTem ERRor Bit Definitions Standard Event Register Bit Decimal Value Definition 0 Operation Complete 1 All commands prior to and including an OPC command have been executed 1 Not Used 2 Always set to 0 2 Query Error 4 The meter tried to read the output buffer but it was empty Or a new command line was rec...

Page 168: ...The standard event enable register is cleared when You turn on the power and you have previously configured the meter using the PSC 1 command You execute a ESE 0 command The standard event enable register will not be cleared at power on if you have previously configured the meter using PSC 0 Chapter 4 Remote Interface Reference The SCPI Status Model 166 ...

Page 169: ...eter s error queue Bit Definitions Questionable Data Register Bit Decimal Value Definition 0 Voltage Overload 1 Range overload on dc volts 1 Not Used 2 Always set to 0 2 Not Used 4 Always set to 0 3 Not Used 8 Always set to 0 4 Temperature Overload 16 Range overload on temperature measurements 5 Not Used 32 Always set to 0 6 Not Used 64 Always set to 0 7 Not Used 128 Always set to 0 8 Not Used 256...

Page 170: ...y the event register using STATus QUEStionable EVENt The questionable data enable register is cleared when You turn on the power PSC does not apply You execute the STATus PRESet command You execute the STATus QUEStionable ENABle 0 command Chapter 4 Remote Interface Reference The SCPI Status Model 168 ...

Page 171: ...e operation of the digital filter You can read the operational status condition register to determine the digital filter state on a per measurement basis You can read the operational status event register to determined if the digital filter ever settled The digital filter count can be reset based upon input signal levels See page 57 If you need to know the digital filter state for a given measurem...

Page 172: ...rational status event register is cleared when You execute a CLS clear status command You query the event register using STATus OPERation EVENt The operational status enable register is cleared when You turn on the power PSC does not apply You execute the STATus PRESet command You execute the STATus OPERation ENABle 0 command Chapter 4 Remote Interface Reference The SCPI Status Model 170 ...

Page 173: ...imal representing the bits set in the enable register STATus QUEStionable EVENt This command queries the Questionable Data event register The meter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register STATus OPERation CONDition This command queries the operational status condition register The meter returns a decimal value which corresponds to the bi...

Page 174: ...s command enables bits in the Standard Event enable register The selected bits are then reported to the Status Byte ESE This command queries the Standard Event enable register The meter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register ESR This command queries the Standard event register The meter returns a decimal value which corresponds to the b...

Page 175: ... power is turned on non volatile memory PSC This command queries the power on status clear setting Returns 0 PSC 0 or 1 PSC 1 SRE enable value This command enables bits in the Status Byte enable register SRE This command queries the Status Byte enable register The meter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register 4 Chapter 4 Remote Interface...

Page 176: ...ut ZERO GAIN This command sets the Chart Output Analog Output to either 0V or 1V output for calibration purposes Use the CALibration VALue and CALibration commands to set the values and perform the calibration CALibration OUTPut This command query returns ZERO or GAIN CALibration SECure CODE new code This command enters a new security code To change the security code first unsecure the meter using...

Page 177: ...ation message may contain up to 40 characters non volatile memory CALibration STRing This command queries the calibration message and return a quoted string CALibration VALue value This command specifies the value of the known calibration signal used by the calibration procedure CALibration VALue This command queries the present calibration value 4 Chapter 4 Remote Interface Reference Calibration ...

Page 178: ...tain information to help you use the meter over the RS 232 interface The programming commands for RS 232 are listed beginning on page 182 RS 232 Configuration Overview Configure the RS 232 interface using the parameters shown below Use the front panel I O MENU to select the baud rate parity and number of data bits see page 101 for more information Baud Rate 300 600 1200 2400 4800 or 9600 baud fact...

Page 179: ...must use a DTE to DTE interface cable These cables are also called null modem modem eliminator or crossover cables The interface cable must also have the proper connector on each end and the internal wiring must be correct Connectors typically have 9 pins DB 9 connector or 25 pins DB 25 connector with a male or female pin configuration A male connector has pins inside the connector shell and a fem...

Page 180: ... 9 Serial Connection If your computer or terminal has a 9 pin serial port with a male connector use the null modem cable included with the 34398A Cable Kit This cable has a 9 pin female connector on each end The cable pin diagram is shownbelow DB 25 Serial Connection If your computer or terminal has a 25 pin serial port with a male connector use the null modem cable and 25 pin adapter included wit...

Page 181: ...l Ready and DSR Data Set Ready lines of the RS 232 interface to handshake The meter uses the DTR line to send a hold off signal The DTR line must be TRUE before the meter will accept data from the interface When the meter sets the DTR line FALSE the data must cease within 10 characters To disable the DTR DSR handshake do not connect the DTR line and tie the DSR line to logic TRUE If you disable th...

Page 182: ...terminate the command string After the response has been output the meter sets the DTR line TRUE again unless the first case see above prevents this The meter monitors the DSR line to determine when the controller is ready to accept data over the interface The meter monitors the DSR line pin 6 on the RS 232 connector before each character is sent The output is suspended if the DSR line is FALSE Wh...

Page 183: ...p bits these values are fixed on the meter Make sure to execute the SYSTEM REMOTE command to place the meter in the REMOTE mode Verify that you have connected the correct interface cable and adapters Even if the cable has the proper connectors for your system the internal wiring may not be correct The 34398A Cable Kit can be used to connect the meter to most computers or terminals Verify that you ...

Page 184: ... send this command before any other RS 232 command can be received SYSTem RWLock This command places the meter in the remote mode during RS 232 operation All keys on the front panel are disabled including the LOCAL key C a u t i o n Sending or receiving data over the RS 232 interface when not configured for REMOTE operation can cause unpredictable results Always make sure the meter is configured f...

Page 185: ...s the colon moves the path down one level in the present path for the specified root level command of the command tree You must separate command mnemonics from each other using a colon You can omit the leading colon if the command is the first of a new program line Using a Semicolon Use a semicolon to separate two commands within the same command string The semicolon does not change the present pa...

Page 186: ...he second response you may receive some data from the first response followed by the complete second response To avoid this do not send a query command without reading the response When you cannot avoid this situation send a device clear before sending the second query command Using Commands Commands starting with a are called common commands They are required to perform the identical function for...

Page 187: ...nput numeric parameters Discrete Parameters Discrete parameters are used to program settings that have a limited number of values like BUS IMMediate EXTernal They have a short form and a long form just like command keywords You can mix upper case and lower case letters Query responses will always return the short form in upper case letters Boolean Parameters Boolean parameters represent a single b...

Page 188: ...y sent with each bus transaction Message termination will always set the current path back to the root level Output Data Formats Output data will be in one of formats shown in the table below Type of Output Data Output Data Format Non reading queries 80 ASCII character string Single reading IEEE 488 SD DDDDDDDDESDD nl Multiple readings IEEE 488 SD DDDDDDDDESDD nl Single reading RS 232 SD DDDDDDDDE...

Page 189: ...nding the control C character will perform the equivalent operations of the IEEE 488 device clear message The meter s DTR data terminal ready handshake line will be true following a device clear message See DTR DSR Handshake Protocol on page 179 for further details TALK ONLY for Printers You can set the meter s HP IB address to 31 which is the talk only mode In this mode the meter can output readi...

Page 190: ...ront panel menu A MEAS MENU 2 Move across to the I O MENU choice on this level F I O MENU 3 Move down a level to the HP IB ADDR command 1 HP IB ADDR 4 Move down to the parameter level to set the address Use the left right and down up arrow keys to change the address 22 ADDR Auto Man 5 Save the change and turn off the menu ENTER The address is stored in non volatile memory and does not change when ...

Page 191: ... and then across to the INTERFACE command 2 INTERFACE 4 Move down to the parameter level to select the interface Use the left right arrow keys to see the interface choices Choose from the following HP IB 488 or RS 232 HP IB 488 Auto Man 5 Save the change and turn off the menu ENTER The interface selection is stored in non volatile memory and does not change when power has been off or after a remot...

Page 192: ...AUD RATE 4 Move down to the parameter level to select the baud rate Use the left right arrow keys to see the baud rate choices Choose from one of the following 300 600 1200 2400 4800 or 9600 baud 9600 BAUD Auto Man 5 Save the change and exit the menu ENTER The baud rate selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset Remote I...

Page 193: ...ct the parity Use the left right arrow keys to see the parity choices Choose from one of the following None 8 data bits Even 7 data bits or Odd 7 data bits When you set parity you are indirectly setting the number of data bits EVEN 7 BITS Auto Man 5 Save the change and turn off the menu ENTER The parity selection is stored in non volatile memory and does not change when power has been off or after...

Page 194: ...MENU choice on this level F I O MENU 3 Move down a level and then across to the LANGUAGE command 5 LANGUAGE 4 Move down to the parameter level to select the language Choose from one of the following SCPI or KEITHLEY 181 SCPI Auto Man 5 Save the change and turn off the menu ENTER The language selection is stored in non volatile memory and does not change when power has been off or after a remote in...

Page 195: ...thley 181 language has been selected you must append the Keithley end of message terminator X to any commands Be aware that measurement timing may be different in the alternate language compatibility modes Specific Issues You should be aware of the following differences when using the Keithley 181 language Unlike the Keithley 181 the status byte is not cleared when read unless the SRQ bit was set ...

Page 196: ...d in this manual for simplicity or clarity Most of these non documented commands duplicate the functionality of a command already described in this chapter CALibration COUNt OUTPut ZERO GAIN OUTPut SECure CODE code string SECure STATe OFF ON 0 1 code SECure STATe returns 0 or 1 STRing string STRing CALCulate FUNCtion SCALe AVERage FUNCtion AVERage MINimum AVERage MAXimum AVERage AVERage AVERage SD...

Page 197: ...mum MAXimum REFerence GAIN REFerence VALue value SAMPle COUNt count MINimum MAXimum COUNt MINimum MAXimum SENSe CURRent BIAS ZERO IMMediate NULL ONCE NULL STATe OFF ON 0 1 NULL STATe NULL VALue value MINimum MAXimum NULL VALue SENSe FRESistance RESistance NULL STATe OFF ON 0 1 NULL STATe NULL VALue value MINimum MAXimum NULL VALue VOLTage LIMit STATe OFF ON 0 1 VOLTage LIMit STATe POWer LIMit STAT...

Page 198: ... TYPE TRANsducer TCouple RJUNction VALue value MIN MAX TRANsducer TCouple RJUNction VALue MINimum MAXimum TRANsducer TCouple RJUNction TYPE FIXed INTernal THERmistor TRANsducer TCouple RJUNction TYPE TRANsducer FRTD TYPE type TRANsducer FRTD TYPE SENSe VOLTage DC NULL STATe OFF ON 0 1 NULL STATe NULL VALue value MINimum MAXimum NULL VALue SYSTem INTerface TYPE HPIB RS232 INTerface TYPE REMote RWLo...

Page 199: ...ble GET Group Execute Trigger SRQ Service Request Interrupt GTL Go to Local LLO Local Lock Out SDC Selected Device Clear SPD Derial Poll disable SPE Serial Poll Enable IEEE 488 2 Common Commands CLS ESE enable value ESE ESR IDN OPC OPC PSC 0 1 PSC RST SRE enable value SRE STB TRG TST WAI 4 Chapter 4 Remote Interface Reference IEEE 488 Compliance Information 197 ...

Page 200: ...5 Error Messages ...

Page 201: ... Front Panel operation Use the SYStem menu command 3 ERROR If the ERROR annunciator is on press Shift Menu Recall to read the errors stored in the queue The errors are listed horizontally on the parameter level The error queue is cleared when power has been off or after a CLS clear status command has been executed To read the error queue from the remote interface SYSTem ERRor Errors have the follo...

Page 202: ...k space instead of a comma Example TRIG COUN 1 or CONF TEMP 1000 0 1 104 Data type error The wrong parameter type was found in the command string You may have specified a number where a string was expected or vice versa Example DISP TEXT 5 0 105 GET not allowed A Group Execute Trigger GET is not allowed within a command string 108 Parameter not allowed More parameters were received than expected f...

Page 203: ...umeric overflow A numeric parameter was found whose exponent was larger than 32 000 Example TRIG COUN 1E34000 124 Too many digits A numeric parameter was found whose mantissa contained more than 255 digits excluding leading zeros 128 Numeric data not allowed A numeric parameter was found when a string or discrete parameter was expected 131 Invalid suffix A suffix was incorrectly specified for a nu...

Page 204: ...arameter type Example CALC STAT ON 160 to 168 Block data errors The meter does not accept block data 170 to 178 Expression errors An incorrect expression for the channel specifier was received The meter does not accept mathematical expressions 211 Trigger ignored A Group Execute Trigger GET or TRG was received but the trigger was ignored Make sure the meter is in the wait for trigger state before ...

Page 205: ...e the string length was more than 11 characters This error can be generated by the CALibration STRing and DISPlay TEXT commands 224 Illegal parameter value A discrete parameter was received which was not a valid choice for the command You may have used an invalid parameter choice Example CALC FUNC SCALE SCALE is not a valid choice 230 Data corrupt or stale A FETCh command was received but internal...

Page 206: ... UNTERMINATED The meter was addressed to talk i e to send data over the interface but a command has not been received which sends data to the output buffer For example you may have executed a CONFigure command which does not generate data and then attempted an ENTER statement to read data from the remote interface 430 Query DEADLOCKED A command was received which generates too much data to fit in ...

Page 207: ...t exceed 1024 readings 532 Cannot achieve requested resolution The meter cannot achieve the requested measurement resolution You may have specified an invalid resolution in the CONFigure or MEASure command 540 Cannot use overload as math reference The meter cannot store an overload reading 9 90000000E 37 as the math reference for null measurements The math state is turned off as a result of this c...

Page 208: ...as been disabled After being set to the voltage limited resistance mode the meter received a command that changed the settings to an mode or range not allowed 1001 Settings conflict power limit mode has been disabled After being set to the low power resistance mode the meter received a command that changed the settings to an mode or range not allowed For example after the low power mode has been e...

Page 209: ...ont panel does not respond 602 RAM read write failed 603 A D sync stuck 604 A D slope convergence failed 605 Cannot calibrate rundown gain 606 Rundown gain out of range 607 Rundown too noisy 608 Serial configuration readback failed 609 DC gain x1 failed 610 DC gain x10 failed 611 DC gain x100 failed Chapter 5 Error Messages Self Test Errors 208 ...

Page 210: ...mV voltage clamp failed 620 Ohms 500 mV voltage clamp failed 621 Low Impedance DC gain X100 failed 622 High Impedance DC gain X100 failed 623 Cannot calibrate precharge 624 Unable to sense line frequency 625 I O processor does not respond 626 I O processor failed self test 627 Hardware overload comparator failed 630 Bias current DAC test failed 5 Chapter 5 Error Messages Self Test Errors 209 ...

Page 211: ...as used to secure it and vice versa The security code may contain up to 11 alphanumeric characters The first character must be a letter 704 Secure code too long A security code was received which contained more than 11 characters 705 Cal aborted A calibration in progress is aborted when you press any front panel key send a device clear or change the local remote state of the meter 706 Cal value ou...

Page 212: ...jected current selfcal failed 740 Cal checksum failed secure state 741 Cal checksum failed string data 742 Cal checksum failed DCV corrections 743 Cal checksum failed Low Power FRES corrections 744 Cal checksum failed RES corrections 745 Cal checksum failed FRES corrections 746 Cal checksum failed Low Voltage FRES corrections 747 Cal checksum failed HP IB address 748 Cal checksum failed internal d...

Page 213: ...6 Application Programs ...

Page 214: ...e starting on page 115 lists the syntax for the SCPI Standard Commands for Programmable Instruments commands available to program the the meter This chapter is divided into the following sections HP BASIC Language Programs page 215 RS 232 Operations with QuickBASIC page 222 Microsoft Visual Basic Programs page 223 C Language Programs page 230 Microsoft Excel Macro Example page 242 214 ...

Page 215: ...of 7 the combination is 722 HP BASIC HP IB Program Example 1 This example demonstrates the general sequence of programming and the use of the MEASure command to set and obtain a 4 wire Ohms measurement 10 20 This program configures the meter for a 4 wire ohms measurement on 30 Channel 1 using the MEAS command 40 50 REAL Value Rdg Dimension real variables 60 CLEAR 7 Clear interface send device clea...

Page 216: ... Send 1 to output buffer when complete 110 ENTER Meter Value Enter value 120 130 Configure channel 1 for dc volts 1 volt range with 10 mV resolution 140 Configure channel 2 for dc volts 1 mV range with least resolution 150 OUTPUT Meter CONF VOLT DC 1 0 01 FRON1 CONF VOLT DC 0 001 MAX FRON2 160 170 OUTPUT Meter ROUT TERM FRON1 Select channel 1 180 OUTPUT Meter READ Take reading send to output buffe...

Page 217: ...2 Enter reading 310 320 OUTPUT Meter SENS2 VOLT DC NULL ON Enable null on channel 2 330 OUTPUT Meter SENS2 VOLT DC NULL VAL Rdg_ch2 Store value in register 340 350 OUTPUT Meter READ Take nulled reading send to output buffer 360 ENTER Meter Null_ch2 Enter nulled reading 370 PRINT Null_ch2 Print nulled reading 380 390 END 6 Chapter 6 Application Programs HP BASIC Language Programs 217 ...

Page 218: ...variables 80 CLEAR 7 Clear interface send device clear 90 ASSIGN Meter TO 722 Assign I O path to address 722 100 COM Meter Use same address in subprogram 110 OUTPUT Meter RST Reset the meter 120 OUTPUT Meter CLS Clear status registers 130 OUTPUT Meter OPC Send 1 to output buffer when reset complete 140 ENTER Meter Value Enter value 150 160 Configure the Status Register system to generate an SRQ wh...

Page 219: ...lect 10 power line cycles 340 OUTPUT Meter CALC FUNC SCAL Select math scaling function 350 OUTPUT Meter CALC STAT ON Turn math scaling on 360 OUTPUT Meter CALC SCAL GAIN 0 001 Set the gain value 1 mV 370 OUTPUT Meter CALC SCAL OFFS 0 5 Set the offset value 50 mV 380 390 OUTPUT Meter SAMP COUN 5 Take 5 reading per trigger 400 OUTPUT Meter TRIG SOUR EXT Select external trigger source 410 OUTPUT Mete...

Page 220: ...the readings to the output buffer and print 600 610 SUB Read_data Subprogram is called after INIT complete and trigger is received 620 DIM Rdgs 1 5 Dimension array for readings 630 COM Meter Use same address as in main program 640 OUTPUT Meter FETC Transfer readings to output buffer 650 ENTER Meter Rdgs Enter readings 660 PRINT Rdgs Print readings 670 STOP 680 SUBEND Chapter 6 Application Programs...

Page 221: ...s 25 How many measurements rows in file 100 Address 722 34420A HPIB address 110 Range 1 E 3 34420A Range 120 Nplc 1 34420A Integration time 130 Num_samples 20 How many samples per measurement 140 ALLOCATE Results 1 Num_points 80 Filename 80 150 Filename B EXAMP_DAT 160 Setup_meter Address Range Nplc Num_samples 170 FOR I 1 TO Num_points 180 DISP Getting VAL I of VAL Num_points measurements 190 OUT...

Page 222: ...tup_meter SUB Setup_meter Address Range Nplc Num_samples 420 OUTPUT Address CLS Clear Status 430 OUTPUT Address SENSE VOLTAGE RANGE VAL Range 440 OUTPUT Address INPUT FILTER STATE OFF 450 OUTPUT Address SENSE VOLTAGE DC NPLC VAL Nplc 460 OUTPUT Address CALC FUNC AVER Take average of 470 OUTPUT Address CALC STATE ON Num_samples 480 OUTPUT Address SAMPLE COUNT VAL Num_samples 490 OUTPUT Address TRIG...

Page 223: ...ut the meter into remote operation mode PRINT 1 SYST REM Query the meter s id string PRINT 1 IDN LINE INPUT 1 resp PRINT IDN returned resp Get the SCPI revision number PRINT 1 SYST VERS LINE INPUT 1 resp PRINT SYST VERS returned resp Send a message to the meter s display PRINT 1 DISP TEXT HP 34420A Configure the meter for dc voltage measurements 10 V range 0 1 V resolution take 4 readings PRINT 1 ...

Page 224: ...2 When sending a remote interface command you append this address to the HP IB interface s select code normally 7 Therefore with an address of 22 and a select code of 7 the combination is 722 Sub Command1_Click Rem Set up interface variables isc 7 device isc 100 22 swap 2 max 4000 swap act 0 max1 50 TimeVal 10 Rem Clear out text boxes Text1 Text Text2 Text Text3 Text Text4 Text Rem Set up the mete...

Page 225: ...nt route ROUT TERM FRONT2 errnum HpibOutputS hHpib device route Len route Call check_srq Take the reading and check for errors errnum HpibOutputS hHpib device reed Len reed errnum HpibEnter hHpib device reading2 Text2 Text Str reading2 Call check_srq Rem Nulled Channel 1 Measurement null_stmt SENS1 VOLT DC NULL ON errnum HpibOutputS hHpib device null_stmt Len null_stmt Call check_srq null_stmt SEN...

Page 226: ...ice reading Text4 Text Str reading Call check_srq Rem Close the instrument errnum HpibClose hHpib End Sub Sub Command2_Click End End Sub Sub Command3_Click Rem Set up interface variables isc 7 device isc 100 22 swap 2 max 4000 swap act 0 max1 50 TimeVal 10 Rem Set up Measurement variables Funct SCAL Trig_src EXT range 10 nplc 100 Gain 001 Offset 5 samp_count 100 ReDim Readings samp_count Rem Clear...

Page 227: ...rq cmd SENS VOLT DC NPLC Str nplc errnum HpibOutputS hHpib device cmd Len cmd Call check_srq cmd CALC FUNC Funct errnum HpibOutputS hHpib device cmd Len cmd Call check_srq cmd CALC STAT ON errnum HpibOutputS hHpib device cmd Len cmd Call check_srq cmd CALC SCAL GAIN Str Gain errnum HpibOutputS hHpib device cmd Len cmd Call check_srq cmd CALC SCAL OFFS Str Offset errnum HpibOutputS hHpib device cmd...

Page 228: ... initiate measurement and read back Rem results into an array cmd INIT errnum HpibOutputS hHpib device cmd Len cmd Call check_srq reed FETC errnum HpibOutputS hHpib device reed Len reed errnum HpibEnterA hHpib device Readings 0 samp_count Text1 Text Str Readings 0 Call check_srq Rem Close the instrument errnum HpibClose hHpib End Sub Sub Command5_Click form1 PrintForm End Sub Chapter 6 Application...

Page 229: ...Enter hHpib device done If there is an error bit set obtain the error errnum HpibSpoll hHpib device response If response And 32 Then syst_err SYST ERR errnum HpibOutPutS hHpib device syst_err Len syst_err errnum HpibEnter hHpib device errx actual 80 MsgBox Error Str errx errnum HpibOutPutS hHpib device CLS 4 End If Obtain other HPIB errors errnum HpibStatus hHpib isc condition Status If errnum NOE...

Page 230: ...se ETIME Msg Timeout Case ECTRL Msg HP IB must be controller Case EPASS Msg Pass control not permitted Case EFILE Msg File I O Error Case ENUMB Msg Invalid Number Case EADDR Msg Improper addressing Case EOPEN Msg Cannot Open This Card Case ENOOPEN Msg Card is not open Case ECLOSE Msg Cannot close card Case EHANDLE Msg Invalid handle for this ISC Case Else Msg What End Select HpibErrStr Msg End Fun...

Page 231: ...program Make sure the necessary PATH statements have been added to your AUTOEXEC BAT file to enable the compiler to find the library and header files see your C language manual to specify the proper paths Link the appropriate HP IB C library file for your compiler the file is located on the HP IB Command Library disk that came with the HP IB Interface Card Use the appropriate library file clhpib l...

Page 232: ... stack size using the F parameter To compile Borland Turbo C programs from the DOS command line using the large memory model execute the following tcc ml path program C path tchhpib lib For example tcc ml b meter c c tc lib tchhpib lib Change the ml parameter to the appropriate setting when compiling in smaller memory models see you C Language manual for more information Once compiled and linked a...

Page 233: ...from GPIB Command Library define ADDR 722L Set GPIB address for meter Function Prototypes void rst_clear void void meter_meas void void check_error char func_name void main void Start of main rst_clear Reset the instrument and clear error queue meter_meas Set up meter for measurement void rst_clear void Reset the meter clear the error queue and wait for commands to complete A 1 is sent to the outp...

Page 234: ...hm_rdg Display reading Call the function to check for errors check_error meter_meas void check_error char func_name Read error queue to determine if errors have occurred char message 80 int length 80 IOOUTPUTS ADDR SYST ERR 9 Read the error queue IOENTERS ADDR message length Enter error string while atoi message 0 Loop until all errors are read printf Error s in function s n n message func_name IO...

Page 235: ...nd Library define ISC 7L Assign GPIB select code define ADDR 722L Set GPIB address for meter Function Prototypes void rst_clear void void meter_meas void void command_exe char commands int length void check_error char func_name void main void Start of main rst_clear Reset the instrument and clear error queue meter_meas Set up meter for measurement void rst_clear void Reset the meter clear the erro...

Page 236: ... IOOUTPUTS ADDR READ 5 IOENTER ADDR rdg_ch1 Channel 1 Turn null on IOOUTPUTS ADDR SENS1 VOLT DC NULL ON 21 Place the null reading into the Null Register To do this suppress the carriage return CR and line feed LF before sending the null reading First disable EOI End or Identify and EOL End of Line IOEOI ISC 0 IOEOL ISC 0 Send SENS header and suppress CR LF IOOUTPUTS ADDR SENS1 VOLT DC NULL VAL 23 ...

Page 237: ...eration and send data IOEOI ISC 1 IOEOL ISC state 2 IOOUTPUT ADDR rdg_ch2 Channel 1 Take nulled reading transfer reading to output buffer and print nulled reading IOOUTPUTS ADDR ROUT TERM FRON1 15 IOOUTPUTS ADDR READ 5 IOENTER ADDR null_ch1 printf Nulled Reading Chan 1 f n null_ch1 Channel 2 Take nulled reading transfer reading to output buffer and print nulled reading IOOUTPUTS ADDR ROUT TERM FRO...

Page 238: ... char func_name Read error queue to determine if errors have occurred char message 80 int length 80 IOOUTPUTS ADDR SYST ERR 9 Read the error queue IOENTERS ADDR message length Enter error string while atoi message 0 Loop until all errors are read printf Error s in function s n n message func_name IOOUTPUTS ADDR SYST ERR 9 IOENTERS ADDR message length Chapter 6 Application Programs C Language Progr...

Page 239: ... shows the use of math scaling include stdio h Used for printf include stdlib h Used for atoi include string h Used for strlen include cfunc h Header file from GPIB Command Library define ISC 7L Assign GPIB select code define ADDR 722L Set GPIB address for meter Function Prototypes void rst_clear void void setup_status void void meter_meas void void command_exe char commands int length void check_...

Page 240: ...s received and readings are available in internal memory To enable the status registers to generate an interrupt you must enable bits in the Status Byte and Standard Event Register Enable bit 5 Standard Event in the Status Byte to recognize activity from the Standard Event Register 2 5 32 IOOUTPUTS ADDR SRE 32 7 Enable bit 0 in the Standard Event Register to interrupt the Status Byte 2 0 1 IOOUTPU...

Page 241: ...FFS 0 5 Set the offset value 50 mV SAMP COUN 5 Take 5 readings per trigger TRIG SOUR EXT Select external trigger source Call the function to execute the command strings shown above command_exe cmd_string sizeof cmd_string sizeof char Initiate the measurement wait for the trigger and then set bit 0 Operation Complete in the Standard Event Register when complete IOOUTPUTS ADDR INIT OPC 9 Loop until ...

Page 242: ... loop IOOUTPUTS ADDR commands loop strlen commands loop void check_error char func_name Read error queue to determine if errors have occurred char message 80 int length 80 IOOUTPUTS ADDR SYST ERR 9 Read the error queue IOENTERS ADDR message length Enter error string while atoi message 0 Loop until all errors are read printf Error s in function s n n message func_name IOOUTPUTS ADDR SYST ERR 9 IOEN...

Page 243: ...ure EOI is disabled and EOL is set to include the lf character Refer to the Instrument Tools for Windows User s Manual for procedures and descriptions of creating a configuration IBC file You can test your interface connection in the Interactive HP IB program by sending an output string of IDN and entering the results A typical response is shown in the example in cell F4 3 Start the HP IB DDE serv...

Page 244: ...nd F G contains the returned data The macro takes temperature measurements every 15 minutes for a 12 hour duration and enters the resulting statistics Individual temperature readings are not stored This macro uses the DATA FEED command to overcome the 1024 memory reading maximum The macro uses the CALCulate STATe OFF and CALCulate STATE ON commands to reset the stats for each 15 minute interval Wi...

Page 245: ...6 Chapter 6 Application Programs Microsoft Excel Macro Example 245 ...

Page 246: ...Chapter 6 Application Programs Microsoft Excel Macro Example 246 ...

Page 247: ...7 Measurement Tutorial ...

Page 248: ...ions The first section discusses the causes of measurement errors The second section describes specific ways to use the meter to minimize measurement errors This chapter is divided into the following sections Measurement Techniques and Sources of Error page 249 Voltage Measurements page 249 Resistance Measurements page 258 Temperature Measurements page263 Cleaning Connector Contacts page 271 Input...

Page 249: ... to reduce problem magnetic field sources Use NPLC 1 if the pickup is power line related 251 Power Line Rejection NMR Set the integration time to 1 or more PLCs 252 Ground Loops The best way to eliminate ground loops is to maintain the meter s isolation from earth do not connect the input terminals to ground If the meter must be earth referenced be sure to connect it and the device under test to t...

Page 250: ...e into the meter on the input leads or cables connected to the rear of the instrument Keeping the test leads and rear panel cables as far removed as possible from high frequency sources will minimize the RFI inteference RFI emissions from the meter meet international standards If your application is extremely sensitive to RFI radiated from the meter use a common mode choke in the input cable as sh...

Page 251: ...est connections are formed using copper to copper crimped connections The table below shows common thermoelectric voltages for connections between dissimilar metals Copper to Approx µV C Copper 0 3 Gold 0 5 Silver 0 5 Brass 3 Beryllium Copper 5 Aluminum 5 Kovar or Alloy 42 40 Silicon 500 Copper Oxide 1000 Cadmium Tin Solder 0 2 Tin Lead Solder 5 Noise Caused by Magnetic Fields If you are making me...

Page 252: ...f the spurious input these errors and their harmonics will average out to approximately zero When you apply power to the meter it measures the power line frequency 50 Hz or 60 Hz and uses this measurement to determine the integration time The table below shows the noise rejection achieved with various configurations For better resolution and increased noise rejection select a longer integration ti...

Page 253: ...voltage VL which is added to the measured voltage To minimize ground loop errors If Vground is a dc voltage keep RL small compared to Ri If Vground is an ac voltage keep RL small compared to Z and set the meter s integration time NPLC to 1 or greater See page 58 RL Lead Resistance Ri Multimeter Isolation Resistance Ci Multimeter Isolation Capacitance V ground Ground Noise Voltage I Vground caused ...

Page 254: ...n below Any resulting voltage VL will appear as an input to the meter As the value of RS approaches 0 so does the error Additionally if Vf is at the power line frequency 50 Hz or 60 Hz the noise can be greatly reduced by setting the meter s integration time NPLC to 1 or greater See page 252 Vf Common Mode Float voltage RS LO Lead Resistance Ri Meter Isolation Resistance Ci Meter Isolation Capacita...

Page 255: ...er test DUT is an appreciable percentage of the meter s own input resistance The diagram below shows this error source Vs Ideal DUT voltage RS DUT source resistance Ri Meter input resistance 10 MΩ or 10 GΩ Error 100 x RS RS Ri Ideal Meter 7 Chapter 7 Measurement Tutorial Measurement Techniques and Sources of Error 255 ...

Page 256: ...blem much more apparent at higher temperatures You can adjust the input bias current to remove these errors The bias current is automatically minimized during the zero calibration procedure see chapter 4 in the 34420A Service Guide You should perform the zero calibration procedure if you are operating the meter at a temperature more than 5 C from the calibration temperature ib meter biascurrent RS...

Page 257: ... is shown In the circuit below with connection A the injected current flows from the earth connection provided by the circuit to the LO terminal of the voltmeter and no noise is added to the measurement However with connection B the injected current flows through the resistor R adding noise to the measurement With connection B larger values of R will make the problem worse The noise caused by inje...

Page 258: ...nections for resistance measurements are shown below See also Resistance Measurement Configuration on page 68 Removing 2 wire Ohm Test Lead Resistance To eliminate offset errors associated with the test lead resistance in 2 wire ohms measurements follow the steps below 1 Short the ends of the test leads together The meter displays the test lead resistance 2 Press Null from the front panel The mete...

Page 259: ...e measured and so the resistance calculated is in error by VEMF Using offset compensation can reduce the errors caused by VEMF To make an offset compensated measurement the meter makes two voltage measurements one with the current source on and one with the current source off and subtracts the two measurements The actual voltage drop across the resistor and the calculated resistance are obtained b...

Page 260: ...ents or other resistive devices with large temperature coefficients be aware that the meter will dissipate some power in the device under test The effects of this power dissipation can affect the measurement accuracy If power dissipation is a problem there are two actions you can take you can select a higher measurement range to reduce the errors to acceptable levels or you can set the meter to th...

Page 261: ...ide layer may be punctured resulting in a lower resistance reading The meter provides a programmable level of open circuit clamping called voltage limited measurements see page 70 This feature is available on the 10 and 100 ohm ranges The open circuit voltage can be clamped at one of three levels 20 mV 100 mV or 500 mV The table below shows the current and voltage levels used Range Test Current Me...

Page 262: ...cted just by RC time constants Errors will be measured when settling after the initial connection and after a range change You may need to increase the delay time before a measurement in these situations see page 87 Errors in High Resistance Measurements When you are measuring large resistances significant errors can occur due to insulation resistance and surface cleanliness You should take the ne...

Page 263: ...rmine which temperature transducer type to use Each transducer type has a particular temperature range accuracy and cost Each type of transducer is described in more detail in the following subsections The table below summarizes some general specifications for each type of transducer Use the table to help select the general type of transducer to use transducer manufacturers can provide you with ex...

Page 264: ...1 kΩ The meter always makes a 4 wire measurement of RTDs to preserve their accuracy Thermistors Thermistors use materials that change resistance with changes in temperature Your meter can measure this resistance and by knowing the characteristics of the thermistor calculates the temperature Thermistors have a higher sensitivity than thermocouples or RTDs This makes thermistors the transducer to us...

Page 265: ...ce however that the connections made between the thermocouple wire and the meter make another thermocouple where the thermocouple s constantan C lead connects to the meter s copper Cu input terminal The voltage generated by this second thermocouple affects the voltage measurement of the type T thermocouple If the temperature of the thermocouple created at J2 the LO input terminal is known the temp...

Page 266: ...sed two additional thermocouples are created For example the connections with a type J thermocouple iron and constantan Two additional thermocouples have been created where the iron lead connects to the meter s copper input terminals Since these two junctions will generate opposing voltages their effect will be to cancel each other However if the input terminals are not at the same temperature the...

Page 267: ... Intermediate Metals eliminates the need for the extra connection This empirical law states that a third metal iron Fe in the example inserted between two dissimilar metals will have no effect upon the output voltage provided the junctions formed are at the same temperature Removing the reference thermocouple makes the connections much easier This circuit is the best solution for accurate thermoco...

Page 268: ...mal block Once the temperature of the isothermal block is known accurate temperature measurements can be made Typically a thermistor is mounted to the isothermal block and used to measure the temperature Thermocouples come in a variety of types The type is specified by a single letter The following table shows the most commonly used thermocouple types and some key characteristics of each MEASUREME...

Page 269: ...a copper lead Low temperature applications E U S British DIN Japanese French Nickel Chromium Purple Brown Red Red Yellow Constantan Red Blue Black White Blue 200 to 1000 C 1 to 1 7 C Highest output voltage Highest resolution N U S British DIN Japanese French Nicrosil Orange N A N A N A N A Nisil Red N A N A N A N A 200 to 1300 C 1 1 to 2 2 C Superior stability to type K at high temperatures R U S ...

Page 270: ... meter The thermistor is then mounted to the isothermal block The meter measures the temperature of the isothermal block and uses the measurement in the temperature calculation Internal Reference value internal thermistor The meter contains an internal thermistor mounted just behind the input connector The internal thermistor is the least accurate way to measure temperature If you use the internal...

Page 271: ... the meter on a smooth level surface so that the front panel is up 4 Apply one drop of DeoxIT to each connector pin in the input connector A convenient method to apply a single drop is to use a clean piece of wire to transfer the liquid from the container provided to the connector 5 Remove any excess DeoxIT from the connector by wiping with a clean soft cloth 6 Engage and disengage the input cable...

Page 272: ...e Source and Sense Thermistor Source and Sense Source and Sense Channel 2 HI LO DCV 4 WireΩ Sense Sense Thermocouple Align keys Wrap cable shield makes earth ground WIRE 22 28 guage copper Rubber Grommet Torque 5 to 7 in lb NOTE key Chapter 7 Measurement Tutorial Input Connector 272 ...

Page 273: ...e with spade lugs You can obtain additional DeoxITÔ part number D100L2 from CAIG Laboratories Inc 16744 West Bernardo Drive San Diego CA 92172 1904 7 Chapter 7 Measurement Tutorial Obtaining Parts For the Input Connector 273 Use the following Agilent Technologies part numbers to obtain replacement input connectors and cables Contact your nearest Agilent Technologies Sales Office for replacement ...

Page 274: ...8 Specifications ...

Page 275: ...002 0 0060 0002 0 0060 0002 0 0060 0002 0 0060 0004 0 0060 0015 0 0070 0004 0 0005 00002 0 0005 00001 0 0005 00001 0 0005 00001 0 0005 00003 0 0005 00003 0 0006 00003 1 Ω 1 Ω 10 Ω 100 Ω 1 KΩ 1 KΩ 1 KΩ Voltage Limited Resistance 5 6 10 000000 Ω 100 00000 Ω 1 mA 100 µA 0 0020 0002 0 0025 0002 0 0050 0002 0 0050 0002 0 0070 0002 0 0070 0002 0 0005 00002 0 0005 00002 1 Ω 5 Ω Channel 1 Channel 2 DCV Ra...

Page 276: ...ENT CHARACTERISTICS DC Voltage Measurement Method Continuously Integrating Multi slope III A D Converter A D Linearity 0 00008 of reading 0 00005 of range Input Resistance 100V Ch1 only 1mV through 10V 10 MΩ 1 10 GΩ in parallel with 3 6 nF Input Bias Current 50 pA at 25 C Injected Current 50 nA pp at 50 or 60 Hz Input Protection 150 V peak any input terminal to Channel 1 LO continuous Channel Isol...

Page 277: ...Resistance 71 2 200 plc 075 062 DCV1 DCV2 71 2 100 plc 15 125 DCV 1 2 61 2 20 plc 75 625 RTD 61 2 10 plc 1 5 1 25 Thermistor 51 2 1 plc 12 5 10 4 51 2 0 2 plc 50 50 41 2 0 02 plc 125 125 System Speeds 6 Configuration Rates 26 s to 50 s Autorange Rate DC Volts 30 s ASCII reading to RS 232 55 s ASCII reading to GPIB 250 s Max Internal Trigger Rate 250 s Max Ext Trig Rate to Memory 250 s 1 For 1 kΩ u...

Page 278: ...utput 1 mV Output Resistance 1 kΩ 5 Update rate once per reading Span and Offset Adjustable Standard Programming Languages SCPI IEEE 488 2 Keithley 181 Accessories Included 4 ft low thermal cable with copper spade lugs 4 wire shorting plug user s manual service manual contact cleaner test report and power cord General Specifications Front Panel Connection shielded low thermal 99 copper contacts Po...

Page 279: ...Dimensions Chapter 8 Specifications 34420A Nano Volt Micro Ohm Meter 280 ...

Page 280: ...onditions as described in the footnotes on the specification pages If you are operating the meter outside the 23 C 5 C temperature range specified apply an additional temperature coefficient error Understanding the of reading Error The reading error compensates for inaccuracies that result from the function and range you select as well as the input signal level The reading error varies according t...

Page 281: ...ding error and range error You can then convert the total measurement error to a percent of input error or a ppm part per million of input error as shown below of input error Total Measurement Error Input Signal Level 100 ppm of input error Total Measurement Error Input Signal Level 1 000 000 Total Measurement Error Example Assume that a 5 Vdc signal is input to the meter on the 10 Vdc range To co...

Page 282: ...or 0 0020 1 2 V 24 µV Channel 2 Range Error 0 0004 10 V 40 µV Total Error 25 µV 4 µV 24 µV 40 µV 93 µV Difference 1 V 1 2 V 0 2 V 93 µV For difference measurements if both channel 1 and channel 2 are using the same range the of reading error can be applied directly to to the voltage difference In the example if both channels are using the 1 V range the total reading error can be computed as Readin...

Page 283: ...ions Ratio Error Channel 1 accuracy in Channel 2 accuracy in Channel 1 Reading Error 0 0020 Channel 1 Range Error 0 0004 Range Reading 0004 10 5 0008 Total Channel 1 Error 0 0020 0 0008 0028 Channel 2 Reading Error 0 0040 Channel 2 Range Error 0 0002 Range Reading 0002 10 mV 10 mV 0002 Total Channel 2 Error 0 0040 0 0002 0042 Ratio Error 0 0028 0 0042 0070 Ratio 5 V 10 mV 500 0 0070 500 0 035 For ...

Page 284: ...s represents seven full digits of resolution The meter can also overrange on the 10 V range and measure up to a maximum of 12 000000 V This corresponds to a 7 1 2 digit measurement with 20 overrange capability Sensitivity Sensitivity is the minimum level that the meter can detect for a given measurement Sensitivity defines the ability of the meter to respond to small changes in the input level For...

Page 285: ...s the U S National Institute of Standards and Technology To be meaningful the accuracy specifications must be accompanied with the conditions under which they are valid These conditions should include temperature humidity and time There is no standard convention among meter manufacturers for the confidence limits at which specifications are set The table below shows the probability of non conforma...

Page 286: ...ication if you are operating the meter outside a 23 C 5 C temperature range Configuring for Highest Accuracy Measurements The measurement configurations shown below assume that the meter is in its power on or reset state It is also assumed that manual ranging is enabled to ensure proper full scale range selection Front Panel Configure the meter for 10 NPLC and use Digital Filter type set to MEDIUM...

Page 287: ...g security code 109 securing 109 unsecuring 108 carrying handle adjusting 16 removing 27 channel input 41 66 scan 41 selecting 41 selecting from remote interface 140 channel parameter 134 chart null 98 100 offset 98 100 rollover 100 span 98 100 chart out 98 100 commands 156 connector 5 98 100 rollover 100 chassis 5 clamping on output 261 cleaning contacts 271 CLEAR 722 85 CMR See common mode rejec...

Page 288: ...ster 159 EOI 186 equivalent NPLC 60 error of range 282 of reading 281 calculating 281 284 total measurement 282 ERROR annunciator 13 error conditions 92 error messages 200 calibration errors 210 211 execution errors 201 207 self test errors 208 209 error queue 92 error string length 92 errors 92 general measurement 249 270 high resistance measurement 262 service request generation 165 test lead re...

Page 289: ... memory 93 internal reference thermistor 22 internal temperature reference 270 internal triggering 84 interrupt with SRQ 163 isothermal block 22 268 K Keithley 181 language compatility 193 keys 2 number of digits 24 range 42 L language alternate programming 193 language restrictions interface selection 105 remote interface 101 lead resistance nulling 45 77 leakage current errors 256 line frequency...

Page 290: ...260 power line cycles 58 252 power line fuse holder 5 14 voltage setting 5 14 power line frequency 252 power on sensing 252 power line noise rejecting 252 power on state 112 114 prepare for use 13 preset 113 printer connections 106 printers 187 programming sequence simplified 126 133 programming language compatibility 193 selection 105 192 Q query commands 184 questionable data register 167 QuickC...

Page 291: ...137 139 remote interface 101 189 resolutiononremoteinterface 137 139 temperature units 71 settling delays 262 settling time 262 shift key 12 shorting plug 273 single trigger 47 single triggering 82 software bus triggering 84 span chart 98 100 specifications 276 interpreting 285 286 temperature coefficients 287 SRQ 162 163 standard event register 165 bit definitions 165 start bit 177 statistics See...

Page 292: ...panel 47 idle trigger state 85 internal 84 multiple readings 86 multiple triggers 86 sources 82 151 wait for trigger state 85 triggering software bus 84 troubleshooting 14 15 RS 232 181 Turbo C 230 241 tutorial front panel menu 33 40 twisted pair connections 249 two wire ohms 258 U unsecuring for calibration 108 V Visual Basic examples 223 229 VM Comp terminal 97 volatile memory 112 voltage connec...

Page 293: ...90 EN 55011 1991 IEC 61000 4 2 1995 A1 1998 EN 61000 4 2 1995 IEC 61000 4 3 1995 EN 61000 4 3 1995 IEC 61000 4 4 1995 EN 61000 4 4 1995 IEC 61000 4 5 1995 EN 61000 4 5 1995 IEC 61000 4 6 1996 EN 61000 4 6 1996 IEC 61000 4 11 1994 EN 61000 4 11 1994 Canada ICES 001 1998 Australia New Zealand AS NZS 2064 1 Limit Group 1 Class A 4kV CD 8kV AD 3 V m 80 1000 MHz 0 5kV signal lines 1kV power lines 0 5 k...

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