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Optical Scientific Inc

 

 

OFS 2000CW User’s Guide 

 

P/N 1910-905 

 

Rev. 03/28/13 

 

59 

11.5 Error Messages  

All OFS 2000 systems are designed with continuous self-test to monitor basic functions. When a fault is 
detected, an error message will display on the front panel to assist users in determining the nature of the 
problem. Some (not all) messages are triggered by status indicator code byte 31 found in the “C” poll data 
output stream. [Section 5.2.2] A brief explanation is provided below. In most cases, the problem can be easily 
resolved with standard trouble shooting methods. If you require further assistance, contact OSI Technical 
Support 

[See Section 13 “Technical Support”]  

 

11.5.1 Fault (1) A and/or B Out of Range  

(Byte 31 code 1) This message appears when received signal levels are above or below the 1.0 to 9.99 Volt 
range. This means that the incoming modulated light beam is too weak for the photodetectors to pick up or so 
strong that the photodetectors are saturated. 
 

11.5.2 Warning (2) Velocity Out Of Range  

(Byte 31 code 2) This message is generated when the value has gone outside the full scale range parameters. 
This can be due to setting the scale range too low. [See Section 4.2.4 Current Loop -1 velocity]  
 

11.5.3 Fault (3) Input Voltage Out of Range 

This message indicates a problem with the DC power supply. Check the +5/+12/-12 VDC voltages are at 
acceptable levels. 
 

11.5.4 Fault (5) Heating Activity Error 

(Byte 31 code 5) This shows a low amperage condition in the heater AC power circuit. Check the heater for 
fault. 
 

11.5.5 Fault (6) Temperature Probe Error 

(Byte 31 code 6) indicates a problem with the temperature probe. Check the temperature probe for fault. 
 

11.5.6 Fault (7) Pressure Probe Error 

(Byte 31 code 7) The pressure sensor is located on the Control Interface Board [Figure 1.8]. Check the 
attached tubing and the vent fitting in the bottom of the Control Box for leak or blockage.  
 

11.5.7 Warning (9) Clean Lens 

(Byte 31 code 9) This message appears when the received signal drops below acceptable strength for a 
prolonged period of time, indicating that the windows have become obscured. [See 

Section 10.2.1 “Window 

Cleaning Procedure”] This may overlap with Section 11.5.1 “A and/or B Out of Range” as low signal strength 
will trigger it, but in this case the OFS should still be functioning 

– just operating with reduced signal. 

 
The OFS is a robust, accurate instrument with a wide range of acceptance. It will report accurately anywhere 
within it’s range of parameters, and operate reliably in adverse environments. However, problems do arise. 
Should you find it necessary, contact OSI Technical Suppo

rt [See Section 13 “Technical Support”] 


 

Summary of Contents for OFS 2000C

Page 1: ...FS 2000CW User s Guide P N 1910 905 User s Guide OFS 2000CW Optical Flow Sensor 03 28 13 OPTICAL SCIENTIFIC INC Tel 301 963 3630 Fax 301 948 4674 2 Metropolitan Ct Suite 6 Gaithersburg MD 20878 USA ww...

Page 2: ...ription of Changes 11 29 2011 Production Release 04 11 2012 Added explanation for second current loop full scale 03 28 2013 Updated OFS 2000C User s Guide to create CW model User s Guide OFS 2000 Cert...

Page 3: ...it Tubing Instructions 26 3 6 2 Pressurization Unit Set Up 26 3 6 3 Pressurization Unit Operation 27 3 7 AC Power Connections 28 3 7 1 Transmitter Unit 28 3 7 2 Control Box 28 3 8 User Interface Conne...

Page 4: ...g 56 11 1 General Troubleshooting Guidelines 56 11 2 Control Enclosure Troubleshooting 57 11 2 1 DSP lndicator LEDs 57 11 2 2 Control Interface Indicators 57 11 3 Transmitter Troubleshooting 57 11 3 1...

Page 5: ...tameter flow meter 21 Figure 3 8 Natural Air Purge 21 Figure 3 9 Compressed Air Purge 21 Figure 3 10 Purge Air at 90 to Vertical Flow 22 Figure 3 11 Rotameter Installation 22 Figure 3 12 Typical Gate...

Page 6: ...e 6 4 TX Rear View 45 Figure 6 5 Receiver A B Lenses 46 Figure 6 6 Receiver LEDs and Flow Direction 46 Figure 7 1 Receiver Window Cat s Eyes 47 Figure 7 2 Transmitter Module 48 Figure 7 3 Beam Centeri...

Page 7: ...oltages Disconnect AC power before servicing Optical Scientific Inc will not be held liable for any accident injury to personnel or damage to property incurred while operating or servicing this equipm...

Page 8: ...LED in the transmitter emits a light beam which illuminates twin photodetectors in the receiver The received signal is amplified and sent to the Digital Signal Processor DSP in the Control Unit The r...

Page 9: ...Optical Scientific Inc OFS 2000CW User s Guide P N 1910 905 Rev 03 28 13 2...

Page 10: ...ture 40 to 60 C Dust Intrusion IP65 Moisture 0 100 condensing with dry purge air supplied Data Output Four 4 20 mA optical isolated outputs Loop 1 Velocity Loop 3 Temperature optional Loop 2 Volume Lo...

Page 11: ...TX and RX units are supplied with integral spool piece flange adapters These adapters provide isolation and are equipped with 1 8 NPT purge air fittings to keep the light path clear The Control Box ho...

Page 12: ...s clean The transmitter housing contains the transmitter optical assembly and transmitter driver circuit board The optical assembly is pre aligned in the factory and needs no focusing just aiming The...

Page 13: ...and gaskets are supplied for installing the Transmitter and flange adapter on the customer s flange A silicone gasket is provided between the housing and the flange adapter to provide a weather tight...

Page 14: ...ution for internal components and OFS Receiver TB1 connections for the Control Box to the RX Unit F TB2 connections for the fault relays and optional Calibration E TB3 connections for 4 20 mA current...

Page 15: ...K Ground Lug User must connect to Earth ground L J5 DB9 RS 232 serial interface connector connects to J5 header on Control Interface PCB M J7 Remote display connector connects to J7 header on Control...

Page 16: ...pressure sensor It connects to a filter fitting at the bottom of the control enclosure See Figure 1 8 This sensor provides an accurate high level analog output signal that is proportional to applied...

Page 17: ...d at 1500W 120V It is recommended that a dedicated branch circuit controlled with a 15A breaker be provided The heater element is 3 4 in diameter 36 long with an INCONEL sheath and threaded to fit a 3...

Page 18: ...meter leading upstream of the OFS and one times the pipe diameter trailing are good enough for OFS to make a representative flow measurement In some cases OFS 2000 units have been installed right at t...

Page 19: ...ream from the heater A certain amount of shifting may be allowed for as not all sites are ideal but the critical parameter is the 8 centerline distance between the heater and the light path This shoul...

Page 20: ...need to measure and know the path length for an OFS meter which is required for example when mounting an opacity meter Therefore in this regard mounting an OFS is simpler Alignment need not be microm...

Page 21: ...the light beam off center The transmitted light beam will still reach the receiver and the system will work However the received signal will be weaker and performance will be compromised Note OFS uses...

Page 22: ...e the flow is dampened somewhat by the stack interior surface Since this falls outside the RATA test area pipe protrusion should not pose a problem For example Figure 2 4 Measured Flow Cross Section I...

Page 23: ...ch is nominally under the user s control Proper use of purge air is discussed in Section 3 4 Purge Air Figure 2 5 Flange Installation Incorrect Figure 2 6 Flange Installation Correct OFS 2000CW is des...

Page 24: ...box 3 2 Required at Control Unit Location Instrument grade air at 2 CFM per head See notes in Sections 3 4 Purge Air and 3 6 Z Purge Air Single phase 100 240 VAC 1 A power with appropriately rated an...

Page 25: ...hes for the TX RX head with Flange Adapter is shown in Figure 3 4 Figure 3 1 Common Vertical Installation Figure 3 2 Common Horizontal Installation Figure 3 3 OFS Mounting Hardware ITEM QTY DESCRIPTIO...

Page 26: ...Optical Scientific Inc OFS 2000CW User s Guide P N 1910 905 Rev 03 28 13 19 Figure 3 4 OFS TX RX Overall Dimensions Units inches...

Page 27: ...Box Mounting Dimensions Note Depth 6 3 8 inches The Control Box may be mounted to a wall or other surface with user supplied hardware It should be located within 15 feet of the RX Unit if the standar...

Page 28: ...from misapplication and or lack of control it s use is not encouraged The use of Active Purge as described herein is recommended for optimum results Active Purge It is recommended the user apply instr...

Page 29: ...ommon sense is encouraged The user should monitor window conditions and adjust purge air incrementally if needed until a balance is reached between affecting the system velocity readings and need for...

Page 30: ...are available Consult OSI Engineering Department A typical installation is shown below Figure 3 12 Typical Gate Valve Installation Install a gate valve or similar shutoff device between the flange ada...

Page 31: ...and practices OSI offers an equipment package which meets established North American requirements and has been found to work satisfactorily This package and recommended configuration is designed to pr...

Page 32: ...TX and RX units and one for the control box Figure 3 15 Typical Z Purge Control Unit When the Z Purge option is ordered the OFS is shipped with vents and air fittings installed as shown in the figure...

Page 33: ...r is closed and Protective Gas Supply is ON 2 Adjust Redundant Regulator if utilized to 5 psi maximum or skip to step 3 if enclosure is equipped with a Model PV 3 Purge Vent 3 Test Purge Vent if utili...

Page 34: ...ization Unit Operation 1 Ensure Protected Enclosure Power is OFF Enclosure Pressure Control Regulator is closed Protective Gas Supply is ON and alarm system is activated if utilized 2 If utilized test...

Page 35: ...tive earth wires must be green yellow in color and be of the same size gauge as the incoming mains supply conductors The Transmitter Board ground plane must be connected to the earth ground with a jum...

Page 36: ...TB2 3 4 Cal Relay TB2 5 No Connection TB2 6 7 Ext Cal Switch connect See Section 3 13 for details Receiver Power and Signal I O TB1 1 2 12V rtn f heater TB1 3 4 8 8VDC RX power TB1 5 Signal Ground TB1...

Page 37: ...t interface board The AGC Cable 1910 810 CW models carries a signal voltage to the Automatic Gain Control AGC circuitry on the transmitter driver board It connects directly to the circuit boards in bo...

Page 38: ...ex 1910 217 XXX where 1910 217 BASIC ASSEMBLY NUMBER XXX CABLE LENGTH IN FEET Customers may opt to make their own cables If this is the case the following information is provided Cables should be 10...

Page 39: ...s routed to the Sensor Interface Board in the Control Box where it is processed and sent to the DSP for integration into the system data 3 11 2 Activator Heater Interconnect The Activator Heater is eq...

Page 40: ...connect wires that have a voltage on them to these terminals The maximum loop resistance is 600 ohms This includes the cable resistance and the load resistor in the customer data acquisition system Lo...

Page 41: ...se when the system enters a calibration check cycle and open when the calibration check is finished 3 13 3 External Calibration Input Pins EARTH and EXT CAL IN are provided for the user to connect to...

Page 42: ...tes a time stamp for every line of data so that events can be easily compared with process data The easiest way to ensure all data is collected is to set the main menu item described as Output Type to...

Page 43: ...se may be left at default values select Windows Keys to use PC type keyboard input Click on the ASCII Setup button 5 The ASCII Setup window will open Select or deselect the following ASCII sending Sen...

Page 44: ...Uppercase Characters Pressing the Enter key at any time will exit the Setup function Change commands will be acknowledged in two steps Erasing Save Buffer Done shows the change command has been accep...

Page 45: ...tead of current loop Three output formats are available 0 Polled Default 1 Continuous Long Constant C poll output 2 Continuous Short Constant A poll output Polled is the normal operating mode for OFS...

Page 46: ...able It is displayed to show the range and confirm the UOM 4 2 5 Correction Factor In some cases there will be a consistent difference high or low offset between the values reported by the OFS unit an...

Page 47: ...from each period and determine an average flow figure This may and often does mean several days and nights of runs to gather a cohesive 3 point data sample Due to customer s operating necessities proc...

Page 48: ...s 4 2 7 Duct Area Data The most basic element in volumetric calculations is the cross sectional area involved Formula for rectangular area Length X Width Area Formula for circular area x R 2 Area Wher...

Page 49: ...mmended R Restart system Note all user set parameters are retained and a calibration check is performed V Displays firmware version installed Note All OFS poll commands are case sensitive Upper case i...

Page 50: ...A A Fixed Field Detector A Signal Strength 14 Comma delimiter 15 18 Carrier Level aaaa Represents detector A carrier strength in volts from 0 10 to 9 99 volts 19 Comma delimiter 20 Detector B B Fixed...

Page 51: ...are dashed out so that it does not cause fault condition 5 2 2 Description of Status Indicator Codes Bytes 29 32 Byte Unit of Measure Description Byte Averaging Time Description sec 29 0 m s 30 0 10 1...

Page 52: ...tion from it Although care is taken in the initial installation of the mounting flanges the beam may not be properly centered Figure 6 3 Centering Light Beam Figure 6 4 TX Rear View Note You will have...

Page 53: ...the locking screw on the right side of the mounting Place your finger on the top edge of the detector board Use your finger to rotate the board left or right until it is aligned with the direction of...

Page 54: ...voltages should be within 30 of each other although If they are not within 30 re do the aim until they are By convention the A detector is the one that first sees the turbulence and is therefore the u...

Page 55: ...oard and have some confidence that it is properly centered Do this exercise with both the Up Down and Side to Side adjustment knobs Figure 7 2 Transmitter Module Figure 7 3 Beam Centering In Figure 7...

Page 56: ...Optical Scientific Inc OFS 2000CW User s Guide P N 1910 905 Rev 03 28 13 49...

Page 57: ...harm to any components but will cause the A B voltage readings to max out and make it difficult to determine when the light beam is truly centered on the receiver module A temporary remedy for this is...

Page 58: ...atch is good enough that we can be confident it was made by the same set of eddies and the velocity output will be within specifications Various factors may affect the shape match of the scintillation...

Page 59: ...e unit of measure to the type preferred 11 Set the time constant to the longest time constant allowed Factory default is 1 minute 12 Set the current loop limit to the just above the highest flow rate...

Page 60: ...or proper measurement Note The control box supplies DC power to the Receiver Figure 9 3 Control Enclosure Display Look inside the Control Enclosure and see that the LEDs on the Control Interface and D...

Page 61: ...when you have to diagnose a problem which has appeared and you want to compare with the way it used to look Biannually or when cleaning windows Installation condition check Inspect the TX Head RX Head...

Page 62: ...e remaining top bolt so that the window is exposed Use commonly available glass cleaner or alcohol to flood the glass windows Be careful they may be HOT Use a soft cloth to wipe away any dirt accumula...

Page 63: ...t buildup Sometimes stack duct gases cool in the nozzles and spool pieces and create fog and mist which can weaken the correlation To see if mist is forming keep the heads installed and use a small br...

Page 64: ...eezes or locks up or will not respond to the V or R poll characters check the PWR Power and ERR Error LEDs on the Control Interface Board If the PWR LED is not lit check the AC Line Voltage and the DC...

Page 65: ...Signal Led Not Lit Be sure the transmitter is transmitting Be sure the light beam path is unobstructed and the windows are clear Check alignment as shown previously in this document Be sure the recei...

Page 66: ...3 Fault 3 Input Voltage Out of Range This message indicates a problem with the DC power supply Check the 5 12 12 VDC voltages are at acceptable levels 11 5 4 Fault 5 Heating Activity Error Byte 31 cod...

Page 67: ...5 1 4 Window Retaining Ring w Gaskets Screws p n 1910 808 5 Control Interface DSP PCB p n 1910 311 1 6 Digital Signal Processor DSP PCB p n 2827 312 12 2 Available Spare Parts Unit Sub Assembly P N TX...

Page 68: ...t It is possible that during periodic cleaning or maintenance of the TX and RX Units the alignment can be disturbed In a well aligned installation the effect of movement is negligible In a marginally...

Page 69: ...ion setting Otherwise a simple scheduled calibration cycle is adequate The thing to remember is that the OFS calibrates itself to an internal reference completely ignoring whatever is being currently...

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