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© 2008 Jackson-Labs

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FireFox Synthesizer User Manual

SCPI Remote Control

2.1 RS-232 SCPI Remote Control

Beginning with Firmware Release 3.0, the FireFox Signal Generator can be controlled remotely 
through a serial RS-232 connection via the built-in 

System

 RS-232 port located on the back-panel. 

The supported commands are compatible with the industry standard SCPI-99 protocol. The SCPI 
protocol originated from HP and the later IEEE GPIB standard commands, and is widely used in the 
industry to control instruments similar to the FireFox.
The FireFox SCPI implementation adheres to the SCPI-99 standard, and achieves compatibility with 
popular competitive Signal Generators and their typical command sets. This assures an effortless 
transition of user-installed legacy software, with most software implementations working 
out-of-the-box without any modification at all.

2.2 SCPI Introduction

Additional information regarding the SCPI protocol syntax can be found on the following web site: 

http://www.scpiconsortium.org

. Please refer to the document 

SCPI-99.pdf

 for details regarding 

individual SCPI command definitions.
A basic familiarity with the SCPI protocol is recommended when reading this chapter.
The FireFox belongs to the SCPI-defined instrument Class “RF & Microwave Sources” and 
implements all the commands necessary to control the output frequency, phase, power and the sweep 
functionality.

2.3 Initiating SCPI Control Mode

The FireFox Signal Generator is controlled by the front-panel keypad by default. The remote control 
mode using the SCPI commands is disabled by default, and needs to be initiated via manual key 
commands. The FireFox SCPI remote control is activated by setting the 

SCPI Mode

 tag located 

under the 

SETUP/COMMUNICATION

 menu option. The user can access this menu option by using 

the front-panel keypad. The FireFox Signal Generator will remain in SCPI mode until the key 

Menu

 

is pressed on the keypad.
By entering the SCPI mode, the SCPI command 

*RST

 is automatically executed, thus initiating the 

unit into a default state.

Summary of Contents for FireFox

Page 1: ...FireFox Synthesizer User Manual Document 0012008 Version 004 Date 10 April 2008...

Page 2: ...FireFox Synthesizer User Manual Copyright 2008 Jackson Labs...

Page 3: ...uick Start Instructions 5 1 4 1 Connecting the instrument 5 1 4 2 Initializing the GPS 5 1 4 3 Setting up the GPS 6 1 4 3 1 GPS Time Offset 6 1 4 3 2 Selecting Metric US Mode 6 1 4 3 3 GPS Auto Survey...

Page 4: ...or Outputs 22 1 6 3 GPS Disciplined OCXO Reference 23 1 6 4 DDS Synthesizer 24 1 6 5 RF Output Buffer 24 1 6 6 User Interface 25 1 6 7 NV memory 25 1 6 8 Frequency Sweeping 25 1 6 9 Differences betwee...

Page 5: ...1 3 1 Overview 41 3 2 General FAQs 41 3 2 1 How can the FireFox Synthesizers offer such high performance for such a low price 41 3 2 2 How did you decide what features to include in the FireFox synthe...

Page 6: ...s in the LCD display indicate 49 3 6 Performance FAQs 50 3 6 1 How does the FireFox Synthesizer offer such wide bandwidth 50 3 6 2 How can spur performance be increased even further 50 3 6 3 Does the...

Page 7: ...eed expensive physics package replacements every 5 years or less and provides better long term time base accuracy than non GPS disciplined Cesium references This manual describes the FireFox GPS disci...

Page 8: ...2 Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Customer Customer supplied software or interfacing unauthorized mod...

Page 9: ...cable with the third wire firmly connected to an electrical ground safety ground at the power outlet Any interruption of the protective grounding conductor or disconnection of the protective earth ter...

Page 10: ...line voltages or frequencies in excess of those stated on the data plate may cause unsafe leakage currents 1 3 8 Do not substitute parts or modify the Instrument Do not install substitute parts or pe...

Page 11: ...rranty 1 4 2 Initializing the GPS Every time the FireFox unit is moved it is recommended to enable the GPS Automatic Site Survey mode or AutoSurvey in order to reacquire its exact new position The aut...

Page 12: ...he SETUP GPS GPS TIME OFFSET menu and select between 12 to 12 hours of time offset to Greenwich Mean Time GMT 1 4 3 2 Selecting Metric US Mode The unit may display GPS height time and date in either M...

Page 13: ...o be selected from the front panel Check the frequency limit setting if you are not able to configure the unit to generate signals up to the 1 64GHz maximum frequency 1 4 5 Setting the RF Amplitude Th...

Page 14: ...on the two LVDS connectors is approximately 300mV peak on each output and this may be used to drive two independent analog inputs with ca 7dBm level when connected via AC coupling 1 4 6 2 Connecting a...

Page 15: ...or resolution and also affects the output phase noise and frequency drift Select FRACT ON to set the DDS to 48 bit Frequency mode or FRACT OFF to turn off the Fractional N mode and set the unit to 32...

Page 16: ...ser may limit the maximum possible analog RF Output Power that can be set via the front panel keys in the frequency setting menu This setting will also affect sweep modes and memory recall modes The u...

Page 17: ...tes then comparing this value to the present phase offset and calculating the error in one minute updates The OCXO temperature shown is measured at the outside of the metal cage of the OCXO and should...

Page 18: ...an I Q baseband DVB T video signal to an RF carrier of 61 25MHz simply set the RF output of the FireFox Signal Generator to 61 25MHz feed the RF output into the LO Mixer input set the RF output ampli...

Page 19: ...any data by pressing the EXIT MENU button All FireFox settings such as Maximum Frequency Power settings the Frequency Power Unit output power and other settings are saved in these memory locations Pl...

Page 20: ...operating for several weeks are 5E 010 for the default OCXO option and 5E 011 for the Double Oven Ultra High Stability OCXO option 1 4 14 Advanced GPS Setup 1 4 14 1 Factory Reset Pressing the enter b...

Page 21: ...et the port you choose and select 9600 Baud communications 4 You should now see Satellite status information and be able to control the receiver with the WinOncore12 program Settings such as Satellite...

Page 22: ...s per Second Linear and Logarithmic 0 1 1000s F1 F2 or F1 F2 F1 Leveled between 40dBm and 10dBm better than 1dBm level accuracy Time Base Stability Aging Warm up time from cold boot 20 Degree Celsius...

Page 23: ...tive mode 0 100 absolute mode power absolute mode accuracy at 0dBm output up to 18dBm 40dBm to 10dBm better than 0 5dBm typi cally LVDS Output Common mode voltage 100 Ohm terminated SMA to SMA connect...

Page 24: ...e using a TSC 5110A Time Interval Analyzer 1PPS GPS Port CMOS compatible BNC output on rear panel Rising edge synchronized to UTC Do not terminate use a 50 Ohm open ended cable Rising edge can be shif...

Page 25: ...ement intervals when locked to GPS The rear panel 1PPS output of the FireFox Signal Generator is driven by the Motorola M12 GPS timing receiver The 1PPS BNC output is only active when the unit is lock...

Page 26: ...achieves a better than 10 12 Stratum 1 long term accuracy The short term accuracy when locked to GPS is typically better than 5x10 10 when measured in 30 minute intervals see Figure 1 2 Please note th...

Page 27: ...and debugging PLL circuits and driving mixers and other RF equipments local oscillator inputs With the frequency sweep features it is possible to use the FireFox synthesizer to design Microwave equip...

Page 28: ...bm output power by the FireFox signal generator The output phase can be controlled in 0 1 degree steps from 180 to 180 degrees allowing very precise alignment of signals for quadrature type applicatio...

Page 29: ...is accurate to within 20ns of UTC is available on this connector Typically an unterminated 50Ohm coax cable is used to provide this signal to optional external Caesium or Rubidium atomic frequency ref...

Page 30: ...signal phase arbitrarily from 180 to 180 degrees with 0 1 degree resolution 1 6 5 RF Output Buffer The FireFox synthesizer has multiple digital outputs and one analog RF signal output This RF output i...

Page 31: ...NV memory even when power is removed from the system 1 6 8 Frequency Sweeping The unit can be used for arbitrary frequency sweeping with linear or logarithmic sweep modes Start Stop and sweep speed s...

Page 32: ...FireFox Synthesizer User Manual 26 2006 Jackson Labs Figure 1 7 FireFox OEM Module System Board Bottom...

Page 33: ...would use the FireFox analog RF output as the Local Oscillator LO driver of the FireFox mixer The RF input of the mixer could then be connected to an external LNA buffer and band select filter The Int...

Page 34: ...FireFox Synthesizer User Manual 28 2006 Jackson Labs...

Page 35: ...ing the SCPI protocol syntax can be found on the following web site http www scpiconsortium org Please refer to the document SCPI 99 pdf for details regarding individual SCPI command definitions A bas...

Page 36: ...eFox Synthesizer Firmware Rev x x RST This command sets back the default values of the Frequency and Sweep subsystem No signal is being generated Power is set to the minimum of 40dBm and the phase off...

Page 37: ...ns are CW FIXed numeric_value unit MODE CW FIXed SWEep CENTer numeric_value unit SPAN numeric_value unit STARt numeric_value unit STOP numeric_value unit 2 5 1 1 1 SOURce FREQuency CW The Continuous W...

Page 38: ...t value is set to 0Hz 2 5 1 1 6 SOURce FREQuency STOP numeric_value This command sets the Stop frequency for the sweep configuration Changing this value will affect Center and Span in the following wa...

Page 39: ...l affect the LVDS CMOS and RF outputs of the FireFox simultaneously In the Software Controlled sweeping mode the microcontroller controls the frequency of the DDS and changes it incrementally at high...

Page 40: ...frequency sweep when the command INITiate IMMEdiate has been issued This command can be issued at any time during a sweep but it will only be activated after the next trigger event The time unit is i...

Page 41: ...decrease in the opposite direction In this case the total duration of the sweep is doubled Upon RST the direction is set to UP 2 5 2 10 SOURce SWEep COUNt numeric value This command determines the nu...

Page 42: ...ion STEPped SOURce SWEep POINTs 3801 SOURce SWEep DWELl 1 e 6 SOURce COUNt 10 OUTPut ON INITiate IMMe Alternative abbreviated style resulting in the same output sweep FREQ MODE SWE STAR 10Mhz STOP 390...

Page 43: ...e defined in the interval PI PI radians or 180 180 Degrees On RST this value is set to 0 2 5 5 Output Subsystem This command controls the RF output connector of the FireFox Signal Generator 2 5 5 1 OU...

Page 44: ...r this command are BAUD numeric_value ECHo ON OFF 2 5 8 1 1 SYSTem COMMunicate SERial BAUD numeric_value This command sets the speed of the RS232 The supported Baud rates are 9600 19200 38400 57600 an...

Page 45: ...may be used to operate the FireFox Signal Generator 2 6 1 Setting the FireFox into Continuous Wave Mode Complete command syntax style SOURce FREQuency CW 123 456 Mhz cr OUTPut ON POWer 0 Alternative a...

Page 46: ...FireFox Synthesizer User Manual 40 2008 Jackson Labs SOURce POWer...

Page 47: ...duce the component count and thus cost while simultaneously increasing the units reliability Only standard off the shelf components are used to guarantee a long life and support time of the unit Other...

Page 48: ...Desktop unit uses the same FireFox OEM board that is also sold separately The desktop unit includes a Swiss made enclosure a power supply an LCD Display a Keypad and external connectors for all the I...

Page 49: ...2GHz analog mixer A general purpose broadband mixer with over 350MHz bandwidth is available on the front panel This can be used in receiver transmitter or transponder applications Any RF signal up to...

Page 50: ...nder scan mode Operation of the LVDS outputs in under scan mode cannot be guaranteed and the LVDS LED is thus turned off The CMOS output is driven in over scan mode between 350MHz and 390390MHz and th...

Page 51: ...Maximum power levels in relative mode typically range from 8dBm to 18dBm depending on the output frequency Absolute mode is used when highly accurate power levels are required Absolute mode sets the o...

Page 52: ...ived RF input signal is then connected to the RF input Mixing the 1 5GHz LO frequency with the 1 4GHz RF signal will generate a 100MHz mixing product the Intermediate Frequency or IF signal which is b...

Page 53: ...alibrate itself this process will take several hours to complete The calibration parameters are stored in its internal Flash memory after the calibration process completes 3 5 GPS Receiver FAQs These...

Page 54: ...n be checked and controlled via a simple null modem serial cable Antenna cable offset satellite mask angles timing information satellite health information as well as GPS vs UTC time base settings are...

Page 55: ...ming receiver is typically stationary and thus allows for much smaller bandwidth tracking filters increasing the timing solution accuracy significantly Comparable navigational receivers have a typical...

Page 56: ...duce out of band spurs These filters can be designed with public domain software see for example Elsie an easy to use filter designer available at www tonnesoftware com or these can be purchased off t...

Page 57: ...ional frequency step that can be generated in Fractional N mode is smaller than the 10 Hz step size of the FireFox system and the value displayed in the LCD can thus be used to estimate the frequency...

Page 58: ...improve the frequency granularity of the output signal a fractional N mode can be enabled that increases the frequency resolution by an additional 16bits The disadvantage of this mode is that it is no...

Page 59: ...rmed up for one to two hours before the auto calibration is started Plug in and turn on the power meter and plug in the FireFox synthesizer into the wall power outlet After warm up and prior to starti...

Page 60: ...sor at 50MHz Plug in the 8482A power sensor into the Power Ref output of the power meter see Figure 4 1 Press the ZERO CAL button on the front of the power meter and follow the instructions in the LCD...

Page 61: ...onnect the power sensor to the FireFox RF Output See Figure 4 2 Use a BNC to N F adapter between the power sensor and the FireFox synthesizer Figure 4 3 shows how to connect the sensor and BNC to N ad...

Page 62: ...The power meter is controlled by the FireFox system controller via a serial port Use a standard RS 232 Null Modem cable with DB 9 female connectors a suitable RS 232 cable is shipped with the FireFox...

Page 63: ...4 4 Initiating Calibration The calibration procedure is started by the FireFox front panel keypad Make sure the two units are connected correctly and follow the procedure below 1 Press the Menu button...

Page 64: ...u Please note that the Calibration sub menu is on the sixth level and thus not visible in the LCD display until you scroll above the top menu item or below the bottom most menu item See Figure 4 5 on...

Page 65: ...Manual 4 Enter the Calibration sub menu 5 Two menu items are shown see Figure 4 6 Setup and Debug Entering Setup will start the actual calibration procedure Debug is used for factory testing Continued...

Page 66: ...lays information similar to Figure 4 7 The auto calibration procedure will take several hours to finish To avoid calibration errors do not disconnect any of the cables or touch any of the buttons on e...

Page 67: ...mode by the FireFox RMT is displayed in the LCD and the unit is communicating as evidenced by the RX TX indicators The Power meter may sometimes also display the ERR indicator this indicator can be di...

Page 68: ...THE UNITS POWER AFTER AND ONLY AFTER THE CALIBRATION IS FINISHED AND YOU SEE THE MESSAGE IN Figure 4 9 You can verify proper operation of the FireFox RF output using the power meter as it is connecte...

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