User Manual - Jackson Labs Technologies, Inc.
Contents
1. GPSTCXO Eval Board User Manual Jackson Labs 4 5 1 SYNChronization SOURce MODE GPS EXTernal AUTO The board may be configured lock to an external IPPS source or the internal GPS receiver A small through hole pad next to the SMA connectors labeled 1PPS IN may be used to feed an external CMOS rising edge 1PPS signal with OV lt x lt 5V signal level and lus minimum pulse width into the unit Use one of the various ground pins on the board as a 1PPS signal return By default the unit is set to GPS It may be hard coded to only use the external 1PPS source by setting EXT or it may be auto switched to the external 1PPS signal if the internal GPS receiver does not generate IPPS pulses for longer than 15 seconds if the signal is too week or there is a GPS failure When set to the AUTO setting the unit will switch back to the internal GPS receiver once 1PPS pulses are generated internally again 4 5 2 SYNChronization HOLDover DURation This query returns the duration of the present or most recent period of operation in the holdover and holdover processes This is the length of time the reference oscillator was not locked to GPS The time units are seconds The first number in the response is the holdover duration The duration units are seconds and the resolution is 1 second If the Receiver is in holdover the response quantifies the current holdover duration If the Receiver is not in holdover the response quantifies the previous hold2. 4 5 8 SYNChronization LOCKed 4 5 9 SYNChronization health 4 5 10SYNChronization DIAGnostic Subsystem 4 6 1 DIAGnostic ROSCillator EFControl RELative 4 6 2 DlAGnostic ROSCillator EFControl ABSolute MEASURE Subsystem 4 7 1 MEASure VOLTage 4 7 2 MEASure CURRent 4 7 3 MEASure 4 8 SYSTEM Subsystem 4 8 1 SYSTem COMMunicate a 4 8 1 1 SYSTem COMMunicate SERial ECHO 4 8 1 2 SYSTem COMMunicate SERial PROmpt 4 8 1 3 SYSTem COMMunicate SERial BAUD 4 8 2 SYSTem STATus c 4 8 3 SYSTem et Ea ONCE i 4 9 SERVO Subsystem 4 9 1 SERVo COARSeDac 4 9 2 SERVo DACGain 4 9 3 SERVo EFCScale 4 9 4 SERVo EFCDamping 4 9 5 SERVo SLOPe 4 9 6 SERVo TEMPCOmpensation 4 9 7 SERVo AGINGcompensation 4 9 8 SERVo PHASECOrrection 4 O 4 q O 2011 Jackson Labs Technologies Inc Jackson ps 4 9 9 SERVo 1PPSoffset 4 9 10SERVo TRACe 4 9 11SERVo 5 Certification and Warranty 5 0 1 Warranty 5 0 2 Limitation of Warranty 5 0 3 Exclusive Remedies 2011 Jackson Labs Technologies Inc GPSTCXO Eval Board User Manual iii GPSTCXO Eval Board User Manual J a C k S on Labs iv 2011 Jackson Labs Technologies Inc Jackson GPSTCXO Eval Board User Manual Labs Introduction 1 1 Overview The GPSTCXO eval board GPSDO includes a high performance GPS receiver that can acquire and track up to 50 GPS signals down to a state of the art 160dBm a 32bit processor th
3. O 2011 Jackson Labs Technologies Inc 3 GPSTCXO Eval Board User Manual J a C k S on Labs 2 1 1 USB serial port The GPSTCXO eval board has an internal RS 232 to USB serial port adaptor This allows the unit to be directly connected to a PC s USB port from which it will receive power and serial control and no external RS 232 to USB adaptor is required The term RS 232 and USB serial port are used interchangeably as the RS 232 port is implemented and connected via the USB serial connection Windows and Linux has built in support for this serial port functionality 2 1 2 Major connections The major connections and features of the GPSTCXO eval PCB are shown in Figure 2 1 Figure 2 1 Major connections to GPSTCXO eval board 0 USB 5V Power and pps 9 o Control UC PE L Pe at i E x 4l a bo Re Ta gt 7 Alternate Power In 10MHz 5V CMOS OUTPUT M Antenna Connector 4 O 2011 Jackson Labs Technologies Inc ksor Jac son ka Table 2 1 shows the GPSTCXO eval board revision 2 0 hardware connectors Table 2 1 GPSTCXO eval board hardware connectors Ref Name Function Specification Pinning JP2 5V Clean 5V Supply 5V DC 10 lt 0 15A lt 10mVac 1 5V 2 GND J1 10MHz CMOS 10MHz Output 5V CMOS 10MHz Output Center 10MHz Output Shield GND Out U3 USB Port Supplies Power and Standard USB 2 0 Full Speed Mini USB control 2 2 Connecting the GPS Antenna Conne
4. To zoom in The mouse is used to set the left extent and the right extent of the portion of the curve that the user wants to fill the screen Click once with the left mouse button on the point that marks the left side of what you want to be the magnified curve Immediately that point becomes the left end of the curve Then similarly click the right mouse button on the curve at the time you wish to be the right most portion of the magnified curve and it immediately becomes the end point on the right side And finally to return to the zoomed out fit to window view left double click on the curve 20 2011 Jackson Labs Technologies Inc Jackson 7 GPSTCXO Eval Board User Manual Remember in order to see all the data in the log file you must either set the span control to zero or right double click in the graph When you have locked the start and stop time using the mouse you can scroll left or right through the data without changing the span To scroll to a later time use Shift Left click To scroll to an earlier time use Shift Right click Double left click to release everything The time span indication at the lower right of the graph will turn red to signify that mouse override is in effect Figure 3 11 Graph display gt GPSCon Utility Pro GPSCon COMB Status Time Map Graph Export Help About 02 36 34 16 11 10 EFC 2 414181 ad 0m sd 0 04m 598 0 17 Temp 93 0 ns TI av 0 03n sd 11n 2 41396
5. EFC Damping overall IIR filter time constant Higher values increase loop time constant Jackson Labs Technologies Inc typically uses values between 10 to 50 Setting this value too high may cause loop instability Phase compensation this is the Integral part of the PID loop This corrects phase offsets between the GPSTCXO eval board 1PPS signal and the UTC 1PPS signal as generated by the GPS receiver Set higher values for tighter phase following at the expense of frequency stability Typical values range from 4 30 25 being the default Setting this value too high may cause loop instability A well compensated unit will show performance similar to the plot in Figure 2 2 when experiencing small perturbations 6 2011 Jackson Labs Technologies Inc J a C k S on GPSTCXO Eval Board User Manual Labs Figure 2 2 GPSTCXO eval board phase compensation plot 71 xj Jackson Labs Fury Firmware Rev 1 1 Lif F1 T TI max ns p 4 S Fiter coeff 0025 ster jr Span mins 1000 Stop Hide GPSCon Utility Pro GPSCon COM2 121 EFC 2 409962 adzOm sd 0 07 m 4 33 Current racking 6 Not Tracking 1 El 4s SS PRN El az s1 113 41 9 15 4 32 232 45 i 65 155 329 2 4099 0 075127 S ie A 28 0 ns TI fav 1 03n sd 4 7 n 5 4 46 0 VTC 6 21 32 17 Oct 2007 p LAT N 27 16 17 454 Lon M 121 57 26 666 MASK 10 deg ANTENNA DELAY 0 ns HET 46 42 m GPS i LA isca pe oa is tere tenia ba AT GPS Selftest OK OCXO Voltage OK
6. PTIMe TIME STRing PTIMe TINTerval PTIME 4 4 1 PTIMe TZONe Returns the local time zone offset 30 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs 4 4 2 PTIMe DATE This guery returns the current calendar date The local calendar date is referenced to UTC time The year month and day are returned 4 4 3 PTIMe TIME This query returns the current 24 hour time The local time is referenced to UTC time The hour minute and second is returned 4 4 4 PTIMe TIME STRing This query returns the current 24 hour time suitable for display for example 13 24 56 4 4 5 PTIMe TINTerval This query is equivalent to the command SYNChronization TINTerval 4 4 6 PTIME This query returns at once the result of the four following queries PTIME DATE PTIME TIME PTIME TZONE PTIME TINTerval 4 5 SYNChronization Subsystem This subsystem regroups the commands related to the synchronization of the GPSTCXO eval board with the GPS receiver The list of the commands supported for this subsystem is the following SYNChronization SOURce MODE GPS EXTermal AUTO SYNChronization SOURce STATE SYNChronization HOL Dover DUR anon SYNChronization HOLDover INITiate SYNChronization HOLDover RECovery INITiate SYNChronization TINTerval SYNChronization IMMEdiate SYNChronization FEEstimate SY NChronization LOCK ed SYNChronization 2011 Jackson Labs Technologies Inc 31
7. and automatically assign a serial port to the unit Windows will automatically load the USB COM driver for the board The user can verify the COM port that windows assigned to the unit under the Computer Management window right click on computer and press the MANAGE button under Windows 7 or go to Control Panel Computer Management The unit should show up as a standard serial port adaptor under the Ports COM amp LPT Icon Please note down this port number as it is required for the initialization of application software The unit will start to search for Satellites as soon as power is applied and will start to lock the internal TCXO to UTC as soon as the Red LED starts blinking with the GPS antenna attached After 1 hour or less the unit should stabilize the frequency and all event indicators should be off resulting in the Green LED to be lit up At this time the Green LED will indicate the unit is fully synchronized to UTC and generating a stable and accurate 10MHz output signal The Green LED may go off momentarily as airflow touches the unit or Sats come in and out of view this is normal behavior You may place the GPS antenna in a window but it is recommended to place the GPS antenna with a full view of the sky for best performance The antenna cable can be extended to 10m or more with high quality antenna cable use quad shielded RG 6 75 Ohms cable or high quality 50 Ohms coax cable without significant loss of signal quality
8. 0 1 77 0 ns start 14 45 02 07 11 10 UTC Send servitar Sat count o Y T Log Status Iv Log sat count T Translate time codes M Log EFC 2 414181 F TltoGPs LIEGE 0 157483 T Log PU fl T Client mode T Continuously read error queue Flash LED Last error 2011 Jackson Labs Technologies Inc Options Update now Ss U ackson Labs FireFly Il_ Firmware Rev 2 19 Lif 440 TI max ng 20 ga Fiter coeff 0025 ser Stop Span mins 15000 a Stop Hide Not Tracking 0 PRN El s VTC 2 36 25 16 Now 2010 LAT N 27 15 29 756 LON W 11 57 40 127 6 80 m MSL 18 02 47 15 11 10 UTC Receiver timeout 2584 95 6348 7 66236 0 0054106 4 072305 0 00530379 21 GPSTCXO Eval Board User Manual Jackson as Figure 3 12 Expanded Graph Display lt 2 GPSCon Utility Pro GPSCon COM8 E ackson Labs FireFly ll Firmware Rev 2 19 Lif 441 E T Tl max ns 20 HAE 4 Temp ae Ir Filter coeff 0 025 Span mins 15000 H Stop Hide 02 38 51 16 11 10 2 478840 158 Not Tracking 1 PRI El z 15 1 40 VTC 3 45 16 Now 2010 LAT N 27 15 29 756 LON W 121 57 40 195 7 30 m MSL LES E gt a 6 be m o 8 69 0 ns start 17 27 41 15 11 10 UTC Send seita IIH 15 11 10 UTC Receiver timeout servitar meien 1 Log set count Translate time codes 2584 95 6348 7 66236 0 0054106 4 072305 0 00530379 Log EFC 2414208 r o F TltoGPs TED 0 1585
9. EFC OK GPS Receiver Status Position Hold 9 MAR s GPSDO Status Locked Tia L dido ogia 3 TS 5 9 ns o start 15 40 54 16 10 07 UTC 16 67 hrs Send ler tar 05 29 48 17 10 07 UTC Receiver timeout tar T Log Status M Log sat count T Translate time codes poi 0 895 1737 6 0 167729 3213 68 0 176266 I LogEFC 2 409962 Options scpi gt V Tlto GPS f44E 08 0 076677 F Log PU fi Client made T Continuously read error queue Flash LED Last error 2 4 Optional Enclosure The GPSTCXO eval board may be inserted into a Hammond enclosure pictured in Figure 2 3 to shield it from airflow and temperature changes Frequency stability will improve significantly when the unit is operated inside an enclosure The enclosure sides will have to be drilled or stamped by the user to provide clearance for the GPSTCXO eval board The Hammond enclosure into which the GPSTCXO eval board fits has the part number Hammond PN 1455C801BK It is available at www mouser com 2011 Jackson Labs Technologies Inc 7 GPSTCXO Eval Board User Manual J a C k S on Labs Figure 2 3 Hammond enclosure 8 2011 Jackson Labs Technologies Inc Jackson GPSTCXO Eval Board User Manual Labs Control and Command Utilities 3 1 Description The GPSTCXO eval board comes with a CD including a freeware program to control and monitor the unit called Z38xx This program runs under Windows and the latest version is also availa
10. attaching the GPSTCXO eval board unit to your PC s Hyperterminal or the Z38xx software available on the included CD ROM or the optional GPSCon software package Please initialize your PC application software to the proper COM port automatically assigned by Windows and configure the application software for 115200 Baud 8 bits no parity 1 stop bit and no flow control where applicable 2 3 1 Help and command overview e A listing of the available USB RS 232 commands can be shown by typing help when using TeraTerm recommended or Hyperterm 2011 Jackson Labs Technologies Inc GPSTCXO Eval Board User Manual GPSTCXO Eval Board User Manual Ja ck S on Labs s IDN can be used to see if the connection works Both commands need to be followed by pressing Enter 2 3 2 Loop parameter adjustment e All loop parameters can be controlled via the RS 232 serial port e Loop parameters are optimized for the OCXO on the board and changing the factory settings may result in the unit s performance to deteriorate The commands to control the loop parameters are part of the servo command See also the SERVO Subsystem section in Chapter 3 Section 4 9 The individual commands are EFC Scale this is the proportional gain of the PID loop Higher values will give quicker convergence and faster locking of the GPS time lower loop time constant lower values give less noise Values between 0 7 and 6 0 are typical
11. eval board to send the NMEA standard string GPGGA every N seconds with N in the interval 0 255 The command is disabled during the initial 4 minute OCXO warmup phase This command has the following format GPS GPGGA lt int gt 0 255 GPGGA shows height in MSL Meters this is different from traditional GPS receivers that display height in GPS Meters The difference between MSL and GPS height can be significant 35m or more are common 4 3 6 GPS GGASTat This command instructs the GPSTCXO eval board to send a modified version of the NMEA standard string GPGGA every N seconds with N in the interval 0 255 The command is disabled during the initial 7 minute OCXO warmup phase This command has the following format GPS GGASTat lt int gt 0 255 This command replaces the regular NMEA GGA validity flag with a decimal number indicating the lock state of the unit Please see section SERVo TRACe for a detailed description of the lock state variable The command allows capture of the position and other information available in the GGA command as well as tracking the lock state and health of the unit s OCXO performance GGASTat shows height in MSL Meters this is different from traditional GPS receivers that display height in GPS Meters The difference between MSL and GPS height can be significant 35m or more are common 4 3 7 GPS GPRMC This command instructs the GPSTCXO eval board to send the NMEA standard string GPRMC every N se
12. for details regarding individual SCPI command definitions A basic familiarity with the SCPI protocol is recommended when reading this chapter 4 2 General SCPI Commands 4 2 1 IDN This query outputs an identifying string The response will show the following information lt company name gt lt model number gt lt serial number gt lt firmware revision gt 4 2 2 HELP This query returns a list of the commands available for the GPSTCXO GPSDO 2011 Jackson Labs Technologies Inc 27 GPSTCXO Eval Board User Manual Jackson Labs 4 3 GPS Subsystem Note Please note that GPSTCXO eval board displays antenna height in MSL Meters rather than in GPS Meters on all commands that return antenna height the legacy Fury GPSDO uses GPS height The GPS subsystem regroups all the commands related to the control and status of the GPS receiver The list of the commands supported is the following GPS SATellite TR Acking COUNt GPS SATellite VISible COUNt GPS GPGGA lt int gt 0 255 GPS GGASTat lt int gt 0 255 GPS GPRMC lt int gt 0 255 GPS XYZSPeed lt int gt 0 255 GPS POSition GPS RESET ONCE GPS 4 3 1 GPS SATellite This group of commands describe the satellite constellation 4 3 2 GPS SATellite TRAcking COUNt This query returns the number of satellites being tracked 4 3 3 GPS SATellite VISible COUNt This query returns the number of satellites PRN that the almanac predicts should be visible giv
13. the UTC phase offset is gt 250ns then the following errors would be indicated 1 UTC phase gt 250ns 0x4 2 OCXO voltage too high 0x40 3 GPS in holdover 0x10 Oring these values together results in 2011 Jackson Labs Technologies Inc 33 GPSTCXO Eval Board User Manual Jackson Labs 0x40 0x10 0x4 0x54 The unit would thus indicate HEALTH STATUS 0x54 A health status of 0x0 indicates a properly locked and warmed up unit that is completely healthy 4 5 10 SYNChronization This query returns the results of these six queries SYNChronization SOURce MODE SYNChronization SOURce STATE SYNChronization LOCK ed SYNChronization HOLDover DURation SYNChronization FEEstimate SYNChronization TINTerval SYNChronization health 4 6 DIAGnostic Subsystem This subsystem regroups the queries related to the diagnostic of the OCXO The list of the commands supported for this subsystem is as follows DIAGnostic ROSCillator EFControl RELative DIAGnostic ROSCillator EFControl ABSolute 4 6 1 DIAGnostic ROSCillator EFControl RELative This query returns the Electronic Frequency Control EFC output value of the internal reference oscillator It returns a percentage value between 100 to 100 4 6 2 DIAGnostic ROSCillator EFControl ABSolute This query returns the Electronic Frequency Control EFC output value of the internal reference oscillator It returns a value in volts between 0 and 5 V 4
14. trace is EFC crystal frequency control voltage The crystal is aging becoming faster in frequency over time This requires the control voltage to be lowered to maintain 10 0MHz exactly A drift of 2mV is visible over 200 hours On the left side of the screen the EFC range over this 200 hour plot is displayed vertically as 0 00193V This means the drift of the EFC voltage due to aging is 88mV per year The EFC sensitivity of the crystal is about 8Hz per volt so the crystal ages at 8Hz V 0 088 V Year 0 704Hz Year drift At 1OMHz 0 704Hz 10MHz 7 04E 08 aging rate per year This is the same as 0 2ppb drift due to aging per day This crystal aging is fully compensated by the firmware with and without GPS reception of course The OCXO heater current is shown in turqoise We can see it ranges from 0 135607A to 0 178146A The OCXO current jumps lower every 24 hours because the unit is sitting next to a window and the sun shines onto the OCXO in the evenings heating it up and thus making the unit use lower power during that event In Figure 3 12 which is a zoom of Figure 3 11 we can see the phase offset error of the internal OCXO to the UTC GPS reference We can see the maximum drift is 77ns to 93ns The average is TI av 0 03ns The standard deviation over the 200 hour plot is sd 1 Ins This means the average error of the 1OMHz phase of this unit over 200 hours is only 1 Ins rms Or in other words the average jitter wander
15. 11 Jackson Labs Technologies Inc 9 GPSTCXO Eval Board User Manual Jackson Labs 3 2 1 1 Parameter Setup Before communication with Z38XX can take place the communications parameters must be set To do so click on the Parameters tab The parameter window will appear as shown in Figure 3 1 Figure 3 1 Z38XX parameter window A Z38XX Parameters Serial Port Com 4 Baudrate Jimi v Databits 8 Stopbits 11 v Party none Graphics EFC 1 2 te Horizontal span minutes 1440 24 1 EFC unit equals 1 0 X10 relative change in OCXO frequency Clock Set PC time every minute Set PC time every hour 7 Set PC time every day Cancel Ok Set the communications parameters as follows e Comm port Windows will assign a comm port Enter that number in the Com box e Baudrate 115 200 e Data bits 8 bits e Stop bits 1 e Parity none 3 2 1 2 Serial Echo For serial communication with Z38XX to work correctly Serial Echo must be turned off see the explanation in the Z38XX manual To turn off serial echo click on the Manual Command Entry tab The drop down menu shown in Figure 3 2 will appear Scroll all the way down and click on SYST COMM SER ECHO OFF Wait until the yellow indicator is lit and then press Send This will send a command to the GPSTCXO and turn off serial echo Note If you want to run GSPcon utility subsequently be sure and turn back on Serial Echo as that program requires it To do so cl
16. 24 T Log PU 1 a clenmi Update now I Continuously read error queue Flash LE Last error 3 3 4 Exporting the graphics 22 The settings which control the mode of the Export function are contained in the Options dialog Export allows you to create an image file of either the graph or the satellite map You select which you want using the radio buttons If you select Graph you have the option to export only that which is currently visible or to export the graph which is a plot of the entire logfile contents Use the checkbox All to make this choice You may nominate a size in X and Y The file format may be BMP JPG GIF or PNG Your settings will be stored and will be the default next time you open this dialog If you choose to export the graph you might want to override the TI max setting in force on the screen display You may do this by entering a non zero value into the Override TT control A value of zero causes the export to take the same setting if any as the screen display The export may be done automatically on a timed basis Simply enter a non zero value in seconds to choose an export time interval To manually export in accordance with the settings press the Export button 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs 3 4 Interpreting the Data Figure 3 11 shows the data acquired by the GPSTCXO eval board unit over a period of more than 200 hours The red
17. 4000 0 4 9 7 SERVo AGINGcompensation This parameter is a coefficient that represents the drift of the EFC needed to compensate the natural drift in frequency of the OCXO due to aging This coefficient is automatically computed and adjusted over time by the Jackson Labs Technologies Inc firmware This command has the following format SERVo AGINGcompensation lt float gt 10 0 10 0 4 9 8 SERVo PHASECOrrection This parameter sets the Integral part of the PID loop Loop instability will result if the parameter is set too high Typical values are 10 0 to 30 0 This command has the following format SERVo PHASECOrrection lt float gt 100 0 100 0 4 9 9 SERVo 1PPSoffset This command sets the GPSTCXO eval board 1PPS signal s offset to UTC in 16 7ns steps Using the SERV 1PPS command results in immediate phase change of the 1PPS output signal This command has the following format SERVo 1PPSoffset lt int gt ns 2011 Jackson Labs Technologies Inc 37 GPSTCXO Eval Board User Manual Jackson Labs 4 9 10 SERVo TRACe This command sets the period in seconds for the debug trace Debug trace data can be used with Ulrich Bangert s Plotter utility to show UTC tracking versus time etc This command has the following format SERVo TRACe lt int gt 0 255 An example output is described here 08 07 31 373815 60685 32 08 2 22E 11 14 10 6 0x54 date 1PPS Count Fine DAC UTC offset ns Frequency Error Estima
18. 7 MEASURE Subsystem This subsystem regroups the queries related of some parameters that are measured on board on the GPSTCXO eval board The list of the commands supported for this subsystem is the following MEASure VOLTage MEASure CURRent MEASure 34 2011 Jackson Labs Technologies Inc Jackson GPSTCXO Eval Board User Manual Labs 4 7 1 MEASure VOLTage This command is not supported in GPSTCXO eval board and will return undetermined values 4 7 2 MEASure CURRent This command is not supported in GPSTCXO eval board and will return undetermined values 4 7 3 MEASure This command is not supported in GPSTCXO eval board and will return undetermined values 4 8 SYSTEM Subsystem This subsystem regroups the commands related to the general configuration of the GPSTCXO eval board The list of the commands supported for this subsystem follows SYSTem COMMunicate SERial ECHO lt ON OFF gt SYSTem COMMunicate SERial PROmpt lt ON OFF gt SYSTem COMMunicate SERial BAUD lt 9600 19200 38400 57600 115200 gt SYSTem STATus SYSTem FACToryReset ONCE 4 8 1 SYSTem COMMunicate 4 8 1 1 SYSTem COMMunicate SERial ECHO This command enables disables echo on RS 232 This command has the following format SYSTem COMMunicate SERial ECHO lt ON OFF gt 4 8 1 2 SYSTem COMMunicate SERial PROmpt This command enables disables the prompt scpi gt on the SCPI command lines The prompt must be enabled when used with
19. EFCFEL 22 39 48 28 10 10 UTC Receiver timeout F TitolDIAGTEMP x 22 33 58 28 10 10 UTC Receiver timeout DIAG TEST RES 22 40 07 28 10 10 UTC Receiver timeout M Logh DIAGTEST ALL 22 40 23 28 10 10 UTC Receiver timeout cont GPS INIT DATE vr mo day 22 42 17 28 10 10 UTC Receiver timeout GPS INIT POS N deg min sec W deg min sec elev Last error 4 3 3 3 Use of the mouse in graph mode Refer to Figure 3 11 for the following description In graph mode the span of the graph may be set using the span setting Alternatively the start and or stop time of the graph may be locked using the mouse Set the start time by left clicking on the desired start point If you wish the stop time may also be locked by right clicking the desired stop point This can all be unlocked by left double clicking anywhere on the graph Double click always causes all of the selected span data to be displayed At the next update cycle the selected span if not set to zero will be enforced However the left click and if chosen the right click always overrides the span setting To display all of the data in the file without manually setting the span to zero you should right double click in the graph This has the effect of setting the start time to zero the stop time to infinity and asserting the mouse override condition To release left double click Since this is harder to describe than to actually do here is a paraphrase of the above
20. Jackson M GPSTCXO Eval Board User Manual Document 80200507 Date 9 December 2011 GPSTCXO Eval Board User Manual Copyright 2010 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs 1 Introduction 1 1 Overview 1 2 General Safety Precautions 1 2 1 Grounding f 1 2 2 Power Connections 1 2 3 Environmental Conditions N e 21 a 2 Quick Start Instructions 2 1 Powering Up the Unit 2 1 1 USB serial port 2 1 2 Major connections 2 2 Connecting the GPS Antenna 2 3 Remote USB serial control 2 3 1 Help and command overview 2 3 2 Loop parameter adjustment 2 4 Optional Enclosure lt O O1 O1 O1 E BW W 3 Control and Command Utilities 9 3 1 Description 9 3 2 Z38XX Utility 9 3 2 1 Installation and Set Up 9 3 2 1 1 Parameter Setup 10 3 2 1 2 Serial Echo T 10 3 2 1 3 Windows Compatibility 11 3 2 2 Running the program 12 3 2 2 1 Zoom and Pan 12 3 2 3 View menu 12 3 2 3 1 Satellite Azimuth Elevation Chart ha t Ree Ee 3 2 3 2 Satellite C N level Chart 13 3 2 3 3 Holdover Uncertainty amp Sats 14 3 2 3 4 Time Stability Measures 14 3 3 GPScon Utility c 16 3 3 1 Installation and Set Up 16 3 3 1 1 Setting the options c 16 3 3 1 2 Communication Parameters 16 3 3 1 3 Auxiliary parameters 17 3 3 1 4 Other options 19 3 3 2 Sending manual commands to the rece
21. S to GPS 1PPS offset Values less than 1E 012 are below the noise floor and are not significant 4 5 8 SYNChronization LOCKed This query returns the lock state 0 OFF 1 ON of the PLL controlling the OCXO 4 5 9 SYNChronization health The SYNChronization health query returns a hexadecimal number indicating the system s health status Error flags are encoded in a binary fashion so that each flag occupies one single bit of the binary equivalent of the hexadecimal health status flag The following system parameters are monitored and indicated through the health status indicator Individual parameters are ored together which results in a single hexadecimal value encoding the following system status information If the OCXO coarse DAC is maxed out at 255 HEALTH STATUS 0x1 If the OCXO coarse DAC is mined out at 0 HEALTH STATUS 0x2 If the phase offset to UTC is gt 250ns HEALTH STATUS 0x4 If the run time is lt 300 seconds HEALTH STATUS 0x8 If the GPS is in holdover gt 60s HEALTH STATUS 0x10 If the Frequency Estimate is out of bounds HEALTH STATUS 0x20 If the OCXO voltage is too high HEALTH STATUS 0x40 If the OCXO voltage is too low HEALTH STATUS 0x80 If the short term drift ADEV 100s gt 100ns HEALTH STATUS 0x100 For the first 7 minutes after a phase reset or a coarsedac change HEALTH STATUS 0x200 As an example if the unit is in GPS holdover and the OCXO voltage is too high and
22. ase Noise psim E f Phase Noise at 10 0 MHz dBc Hz 0 _60 0 10 dB Div 7001 LU LU LUN LUN LUN TU 90 0 BH HI BH HH 100 0 x RAM Lil iii 1100 BRAS LOL LIN LOUE LUN Ee eo ans BAM LD QUE a 140 0 soo A U C A M BR CHU RH Ss SS Bia 0 10 102 103 104 To ET Offset Freguency Hz Time Constant co Input 10 0 MHz 12 dBm Reference 10 0 MHz 13 dBm 2011 Jackson Labs Technologies Inc 25 GPSTCXO Eval Board User Manual Jackson Labs 26 2011 Jackson Labs Technologies Inc Jackson GPSTCXO Eval Board User Manual Labs SCPI Control Quick Start Instructions 4 1 Introduction The SCPI Standard Commands for Programmable Instrumentation subsystem is accessed via the USB RS 232 interface and a terminal program By default the terminal settings are 115200 8N1 Use terminal programs such as Tera Term recommended or Hyperterm or use the command and control window functions of Z38xx or GPSCon application programs to send commands to the GPSTCXO eval board There are a number of commands that can be used as listed below Most of these are identical or similar to Symmetricom 58503A commands To get a listing of the available commands send the HELP query This will retum a list of all the available commands for the GPSTCXO eval board GPSDO 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
23. at runs a Real Time OS a low noise 5V CMOS 10MHz output USB control interface precision voltage references and DACs The unit is built as an easy to use evaluation board that operates and receives power by plugging into a PC USB port and into a GPS antenna The board is supplied with a USB cable a GPS antenna Z38xx control plotting and command Windows application and a quick start guide The unit provides an industry standard NMEA GPS interface that can be enabled via software command and provides Position Velocity Timing PVT information and also provides a UTC synchronized 1PPS signal on the USB serial port DCD pin The unit can optionally be operated from an external 5V DC power supply instead of the USB cable 1 2 General Safety Precautions The following general safety precautions must be observed during all phases of operation of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Jackson Labs Technologies Inc assumes no liability for the customer s failure to comply with these requirements 1 2 1 Grounding To avoid damaging the sensitive electronic components in the GPSTCXO eval board GSPDO always make sure to discharge any built up electrostatic charge to a good ground source such as power supply ground This should be done before handling the circuit board or anything connected to it
24. ble on the Jackson Labs Technologies Inc website www jackson labs com under the Support tab Z38xx can be used to monitor and graphically plot the frequency and phase stability of the unit the number of Satellites being tracked and various other GPS and TCXO performance parameters Z38xx needs to be properly configured under the PARAMETERS tab prior to operation by setting up the correct serial parameters 115 2K Baud 8N1 Please consult the Z38xx user manual included in the CD ROM for further details Alternatively to the Z38xx application GPSCon is a third party program for the monitoring and control of a variety of GPS time and frequency standard receivers It communicates with the receiver using the SCPI command set via the USB port This utility can be obtained directly from Real Ham Radio com at the following URL http www realhamradio com gpscon buy now htm Important note On newer faster computers running Windows 7 GPSCon may not acquire data correctly If you encounter this problem it is recommended that you install GPSCon on a slower computer using Windows XP or try running GPSCon in Windows XP compatibility mode 3 2 Z38XX Utility 3 2 1 Installation and Set Up The Z38XX manual has instructions on how to install and set up the software All the information needed to run the program is available in the included user manual Only some details of setup and use will be provided here for convenient reference 20
25. bout the different display parameters for this window please consult the Z8XX User Manual 14 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs Figure 3 6 Time Stability measures window Z3BXX Time Stability Measures Chart Editor 2011 Jackson Labs Technologies Inc 15 GPSTCXO Eval Board User Manual Jackson Labs 3 3 GPScon Utility 3 3 1 Installation and Set Up Follow the directions that come with GPSCon for installing the utility on your computer The GPSCon utility has a help file that should be consulted in order to get the full functionality of this utility Only a few of the features and commands are mentioned in this chapter for convenience 3 3 1 1 Setting the options To set up the options for your GPSCon session press the Options button below the display area The window shown in Figure 3 7 will appear You can select from the tabs which options you wish to set Figure 3 7 Options window GPSCon Utility Pro GPSCon COMA Do suo A a ES Time a e r Export Help About Paths amp settings FTP Email Coms Time services Asian Aux coms Export graphics Remote control r Logging and graph M Log Status gpscon apsic M Log EFC Max kB 0 unlimited Interval 130 secs IV Log sat count M Tito GPS Local HTML and image files HTML file c program files amp 86 gpscon gpsstat htm Browse M Le PU Bit from dis
26. c 5 0 2 Limitation of Warranty EXCEPT AS EXPRESSLY PROVIDED HEREIN JACKSON LABS MAKES NO WARRANTIES OF ANY KIND WHETHER EXPRESS IMPLIED STATUTORY OR OTHERWISE AND SPECIFICALLY DISCLAIM ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTIES OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE QUIET ENJOYMENT AND NON INFRINGEMENT OF THIRD PARTY RIGHTS TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW The foregoing warranty shall not apply to Customer supplied software or interfacing unauthorized modification or misuse opening of the instruments enclosure or removal of the instruments panels operation outside of the environmental or electrical specifications for the product or improper site preparation and maintenance JACKSON LABS TECHNOLOGIES INC SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE No license express or implied by estoppel or otherwise to any intellectual property rights is granted by this document Jackson Labs Technologies Inc products are not intended for use in medical life saving or life sustaining applications 5 0 3 Exclusive Remedies THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER S SOLE AND EXCLUSIVE REMEDIES JACKSON LABS TECHNOLOGIES INC SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY 2011 Jackson Labs Technologies Inc 41 FireFly 1A User Ma
27. ces to be visible on the graph 7 EFC Mag Label Offset F TI M Ant focxo cur fo 3 3 1 4 Other options The other tabs in the options window can be selected and you can set whatever options you need such as paths for logging or exporting graphics 3 3 2 Sending manual commands to the receiver You can send SCPI commands manually by using the drop down box under the display window as shown in Figure 3 10 Care must be taken when sending these commands so be sure that the command that you select is supported by the GPSTCXO eval board GPSDO Once you ve selected the command you can press Send to send it to the GPSTCXO eval board 2011 Jackson Labs Technologies Inc 19 GPSTCXO Eval Board User Manual Jackson Labs Figure 3 10 Sending manual commands ou BE Status Time Map Graph Export Help About VdmLabs Firmware Rev 2 19 Life F1 Not Tracking 3 Stat IM ss PRN El Az 23 15 2 157 Stop 36 18 7 201 16 26 4 118 Hide 35 31 32 32 35 11 UTC 22 56 52 28 Oct 2618 LAT N 37 16 52 397 LON W 121 59 15 645 74 16 m HSL OCxO Current OK GPS Receiver Status 3D Fix 1PPS SOURCE MODE GPS 1PPS SOURCE STATE GPS GPSDO Status Locked Send v 22 39 10 28 10 10 UTC Receiver timeout 5 10G S 22 39 20 28 10 10 UTC Receiver timeout Mite Da TOG A aad 22 39 29 28 10 10 UTC Receiver timeout F L DIAG ROSC EFC ABS E 22 39 39 28 10 10 UTC Receiver timeout RN BIAGROSC
28. conds with N in the interval 0 255 The command is disabled during the initial 4 minute OCXO warmup phase This command has the following format GPS GPRMC lt int gt 0 255 2011 Jackson Labs Technologies Inc 29 GPSTCXO Eval Board User Manual Jackson Labs 4 3 8 GPS XYZSPeed Firmware version 0 909 and later add a 3D velocity vector output command Enabling this command will output a 3 dimensional velocity vector indicating the unit s speed in centimeters per second as well as the Time Of Week in milliseconds X Y and Z speed are individually given and are independent of each other An accuracy estimate in centimeters per second is also given The velocity data is time stamped using the time of week with a resolution of milliseconds Use the following format to generate the velocity vector every N seconds with N in the interval 0 255 GPS XYZSPeed lt int gt 0 255 4 3 9 GPS POSition This command will return the position and height of the GPS antenna including velocity and track over ground 4 3 10 GPS RESET ONCE This command will re initialize the GPS receiver 4 3 11 GPS This query displays the configuration position speed height and other relevant data of the GPS receiver in one convenient location 4 4 PTIME Subsystem The PTIME subsystem regroups all the commands related to the management of the time The list of the commands supported is the following PTIMe TZONe PTIMe DATE PTIMe TIME
29. ct the GPS antenna to the MMCX connector shown in Figure 2 1 Please make sure to connect the GPS antenna prior to connecting the USB or power cable to the unit Caution use a Lightning Arrestor on your Antenna setup The GPSTCXO eval board GPS receiver includes a 50 channel high sensitivity GPS receiver with very fast lock time It does not require any self survey or position hold mode auto survey and thus can be used in mobile platforms The GPSTCXO eval board is capable of generating standard navigation messages see GPS GPGGA and GPS GPRMC RS 232 commands that are compatible with most GPS based navigation software Please note that GPSTCXO eval board indicates MSL height rather than GPS height in its GPGGA GPS and syst stat output strings The GPS receiver generates a IPPS time signal that is phase synchronized to UTC This 1PPS signal is used to frequency lock the 10MHz Sine Wave output of the GPSTCXO eval board GPSDO to UTC thus disciplining the unit s 10MHz frequency output to the US Naval master clock for very high frequency accuracy typically better than 2ppb of frequency accuracy when locked to GPS Over the long term the GPSTCXO eval board will out perform free running Cesium Atomic Frequency Standards 2 3 Remote USB serial control e The unit is controlled via the USB Serial port at 115200 baud 8N1 Other Baud Rates can be set via SCPI commands over the serial port e Connect the PC via the USB cable and connector
30. e such as e Satellite Azimuth Elevation Chart e Satellite C N level Chart e Time Stability measures e Clock Display e EFC Statistics e Receiver Status 2011 Jackson Labs Technologies Inc J a C k S on GPSTCXO Eval Board User Manual Labs e Status Log e Error Log 3 2 3 1 Satellite Azimuth Elevation Chart From the drop down View menu select Satellite Azimuth Elevation Chart You will see a polar graph like the one shown in Figure 3 4 It may take a few hours for the graph to display all the satellites within your antenna s view The chart changes over time as the satellites move in and out of view Reset Horizon Line Print 3 2 3 2 Satellite C N level Chart Select Satellite C N level Chart from the View menu and observe the chart shown in Figure 3 5 This graph show the Carrier to Noise ratio of each satellite being tracked 2011 Jackson Labs Technologies Inc 13 GPSTCXO Eval Board User Manual Jackson Labs Figure 3 5 Satellite C N chart Satellite C N Chart EMA Q o N on N o on sa 5 Q 5 G a fa D pu zZ o T U o 3 2 3 3 Holdover Uncertainty amp Sats These parameters are not supported by the GPSTCXO 3 2 3 4 Time Stability Measures Select Time Stability Measures from the View menu to bring up the chart shown in Figure 3 6 This chart is primarily used to display the Allan Deviation for the GPSTCXO To learn more a
31. en date time and position 4 3 4 NMEA Support 28 The following two commands allow the GPSTCXO eval board GPSDO to be used as an industry standard navigation GPS receiver The GPGGA and GPRMC NMEA commands comprise all necessary information about the antenna position height velocity direction satellite info fix info time date and other information that can be used by standard navigation applications via the GPSTCXO eval board RS 232 interface Once enabled GPSTCXO eval board will send out information on the RS 232 transmit pin automatically every N seconds All incoming RS 232 commands are still recognized by GPSTCXO eval board since the RS 232 interface transmit and receive lines are completely independent of one another O 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs Please note that the position direction and speed data is delayed by one second from when the GPS receiver internally reported these to the GPSTCXO eval board Microprocessor so the position is valid for the 1PPS pulse previous to the last 1PPS pulse at the time the data is sent one second delay The time and date are properly output with correct UTC synchronization to the 1PPS pulse immediately prior to the data being sent Once set the following two commands will be stored in NV memory and generate output information even after power to the unit has been cycled 4 3 5 GPS GPGGA This command instructs the GPSTCXO
32. i e the GPS antenna 1 2 2 Power Connections Make sure to connect the DC power to the device following the polarity indicated in Section 2 1 Do not reverse the power pins as this will cause serious damage to the circuit board 2011 Jackson Labs Technologies Inc 1 GPSTCXO Eval Board User Manual Ja ck S on Labs 1 2 3 Environmental Conditions This instrument is intended for indoor use It is designed to operate at a maximum relative non condensing humidity of 95 and at altitudes of up to 4000 meters Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range 2 2011 Jackson Labs Technologies Inc Jackson GPSTCXO Eval Board User Manual Labs Quick Start Instructions 2 1 Powering Up the Unit The unit is powered directly from the USB cable OR from a 5V DC source on connector JP2 Do not connect both the USB cable and the external 5V DC source at the same time this will lead to possible damage to the PC or the 5V DC power supply The current is typically less than 0 15A at 5V Connect a clean 5V power supply to JP2 if the USB cable is not going to be used See Figure 2 1 for the proper polarity of the optional external 5V DC power connection Warning Do not reverse the polarity on the power connector this will damage the unit When using the unit through the USB cable Windows Vista Windows 7 and Linux will auto recognize the unit as a USB serial COM adaptor
33. ick on the Manual Command Entry tab and scroll down to the menu item SYST COMM SER ECHO ON Wait until the yellow indicator is lit and then press Send 10 2011 Jackson Labs Technologies Inc J a C k S O n GPSTCXO Eval Board User Manual Labs Figure 3 2 Manual Command window STB LED ACTIVE ON LED ACTIVE OFF LED ENABLED ON LED ALARM USER ON PTIME LEAP ACO PTIME LEAP GPST PTIME LEAP DUR PTIME LEAP STAT PTIME UTC PTIME TIME PTIME DATE PTIME TIME STRING PTIME TZONE PTIME TZONE 12 12 PTIME TCODE PTIME TCODE FORM PTIME TCODE FORM F1 F2 w PTIME TINTERVAL PTIME TCOD CONT 0 DIAG LIF COUNT DIAG ROSC EFCABS DIAG ROSC EFC REL DIAG TEST ALL DIAG TEMP DIAG TEST RES DIAG GPS UTC DIAG IDEN GPS 3 2 1 3 Windows Compatibility Z38XX may not operate properly under the Windows Vista or Windows 7 operating systems It is best to start these versions of Windows in XP Compatibility Mode This will ensure proper operation of the program Of course you can try running under Windows Vista or 7 as it does work on some systems 2011 Jackson Labs Technologies Inc 11 GPSTCXO Eval Board User Manual Jackson Labs 3 2 2 Running the program When Z38XX starts up the main window appears as shown in Figure 3 3 The window can be moved or resized as desired It is necessary to wait about 20 seconds after starting the program for the software to establ
34. ish communications with the GPSTCXO The main graph shows the EFC Electronic Frequency Control digital control value scale on the right in red and the GPSR I pps TI compared with the mean GPS derived I pps in blue scale on the left The graph is auto scaling on both parameters 3 2 2 1 Zoom and Pan In the main graph window you can zoom in to get more detail To do so position the cursor at the bottom or top of the screen next to the beginning of the area you wish to zoom in on Using the left mouse button drag the cursor up and to the right or down and to the left to the end of the desired zoom area When you release the mouse button the display will zoom in on the desired area To unzoom drag the cursor in the opposite direction from the bottom right up and left or from the top down and left The display will return to the full graph again To pan within the graph display use the right mouse button to drag the graph around the window Figure 3 3 Z38XX main window Z38XX Vers 20090716 Parameters View Manual Command Entry Write Comment to Log Chart Editor Debug Window About PPS TI amp EFC 600x107 400x107 200x107 66240 200x107 0 pd n a a 400407 60040 500x10 07 19 00 00 07 19 06 00 07 19 12 00 07 19 18 00 PPS TI 5 20E 09s EFC 583961 HUP 6 S0E 06 s LIFE 20915 Visible 10 Tracked 8 3 2 3 View menu 12 The View menu allows you to view different aspects of the GPSTCXO performanc
35. iver 19 3 3 3 Use of the mouse in graph mode 20 3 3 4 Exporting the graphics 22 3 4 Interpreting the Data 23 3 5 Performance 4 S gs Ss ooo 0 SRD RE a RES sad 4 SCPI Control Quick Start Instructions 27 4 1 Introduction Hoag Z so dim de aa oe dk 4 T 4 2 General SCPI Commands BY es s i o ties HA cee ee es a He ee ee ee ee 4 2 1 IDN 4 1 422 HELP sms ba a be amp eR Dh bw bee 7 4 3 GPS Subsystem 28 2011 Jackson Labs Technologies Inc i GPSTCXO Eval Board User Manual 4 3 1 GPS SATellite 4 3 2 GPS SATellite TRAcking COUNI 4 3 3 GPS SATellite VISible COUNt 4 3 4 NMEA Support 4 3 5 GPS GPGGA 4 3 6 GPS GGASTat 4 3 7 GPS GPRMC 4 3 8 GPS XYZSPeed 4 3 9 GPS POSition 4 3 10GPS RESET ONCE 4 3 11GPS 4 4 PTIME Subsystem 4 4 1 PTIMe TZONe 4 4 2 PTIMe DATE 4 4 3 PTIMe TIME 4 4 4 PTIMe TIME STRing 4 4 5 PTIMe TINTerval 4 4 6 PTIME 4 5 SYNChronization Subsystem 4 5 1 SYNChronization SOURce MODE ISPSIEXTemallAUTO l 4 5 2 SYNChronization HOLDover DURation 4 5 3 SYNChronization HOLDover INITiate 4 5 4 SYNChronization HOLDover oe INITiate 4 5 5 SYNChronization TINTerval 4 5 6 SYNChronization IMMEdiate 4 5 7 SYNChronization FEEstimate
36. nual 42 Jackson G 2011 Jackson Labs Technologies Inc
37. over The second number in the response identifies the holdover state A value of 0 indicates the Receiver is not in holdover a value of 1 indicates the Receiver is in holdover 4 5 3 SYNChronization HOLDover INITiate The command will place the unit into a forced holdover state while still indicating the difference between the internal 1PPS generated by the OCXO and the GPS generated 1PPS This command is useful to measure the OCXO drift when in holdover Please note that the Time Interval Counter is limited to 2000ns display range The time interval difference may be displayed with the SYNC command 4 5 4 SYNChronization HOLDover RECovery INITiate This command terminates a manual holdover that was initiated with the SYNC HOLD INIT command and return the unit to normal GPS locking mode 4 5 5 SYNChronization TINTerval This query returns the difference or timing shift between the GPSTCXO eval board 1 PPS and the GPS 1 PPS signals The resolution is 1E 10 seconds 4 5 6 SYNChronization IMMEdiate This command initiates a near instantaneous alignment of the GPS 1 PPS and Receiver output 1 PPS To be effective this command has to be issued while not in holdover 32 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs 4 5 7 SYNChronization FEEstimate This query returns the Frequency Error Estimate similar to the Allan Variance using a 1000s measurement interval and comparing the internal 1PP
38. over 200 hours of operation is lins 200Hrs 1 528E 014 or in other words the unit performs as well as a high quality Cesium Atomic reference clock over long periods of time The unit disciplines its internal 10MHZ reference to within less than 80ns peak to peak of UTC at all times which is less than one complete clock cycle at 10MHz 2011 Jackson Labs Technologies Inc 23 GPSTCXO Eval Board User Manual Jackson Labs 3 5 Performance Some typical performance parameters for the GPSTCXO Eval board are shown in the following figures Figure 3 13 shows the typical Allan Deviation performance of the GPSTCXO eval board after one week of burn in locked to GPS and shielded from airflow Corrections from the GPS receiver improve the short term phase stability of the TCXO oscillator above 50 second averaging times Figure 3 13 Typical GPSTCXO Allan Deviation 26 Nov 2011 14 33 05 Symmetricom5125A 13d 4h Allan Deviation oy t 10 9 To z 1 ms NEG BW 500 Hz 10 10 10 11 10 12 10 13 10 14 10 15 10 16 103 10 2 104 10 10 102 105 104 105 106 Averaging Time t seconds Input 10 0 MHz 12 dBm Reference IN REF Figure 3 14 is a plot of typical GPSTCXO eval board phase noise performance while locked to GPS The noise floor can be seen to be below 155dBc 24 2011 Jackson Labs Technologies Inc J a C k S O n GPSTCXO Eval Board User Manual Labs Figure 3 14 Typical GPSTCXO Ph
39. play bitmap M Translate time codes Pixels 317 HTML update interval 120 E secs T Continuously read error queue Flash LED Satellite tracking history file IV Use bitmap Y Track file c program files amp 86 gpscon gpsdmp bin Browse M Statistics Max kB 0 unlimited 1512 EE IV Show best fit to EFC T ANSI font in status T Timax g ns Filter coeff 0 025 Span 2020 a mins 3 3 1 2 Communication Parameters Before you can use GPSCon you must set the communication parameters for your system Open the dialog box by pressing the Options button Then select the Coms tab You will see the window shown in Figure 3 8 16 2011 Jackson Labs Technologies Inc J a ck S on GPSTCXO Eval Board User Manual Labs Set the communications parameters as follows e Comm port Windows will assign a comm port Enter that number in the Com box e Baudrate 115 200 e Data bits 8 bits e Stop bits 1 e Parity none s Flow Control None Once you have configured the communication parameters press the OK button to close the window For proper communication between the GPSTXCO and GPScon SYST COMM SER ECHO must be set to ON Although this is the factory default it could have been set to OFF for use with the Z38XX utility To set it to ON open the manual command dialog box see Section 3 3 2 Manually enter the command SYST COMM SER ECHO ON and press the Send button 3 3 1 3 Auxiliary pa
40. rameters After pressing the Options button you can select Auxiliary and set other options or measurements See Figure 3 9 for an example of an auxiliary measurement You will notice that the Aux request string has been set to meas current lt CD gt and the Log Aux1 box is checked In the area below labeled Traces to be visible on the graph the box Aux 1 is checked and the label OCXO curr has been added 2011 Jackson Labs Technologies Inc 17 GPSTCXO Eval Board User Manual Jackson Labs Figure 3 8 Setting the communications parameters oo o GPSCon Utility Pro GPSCon COM4 fel Status Time C RTS CTS 18 2011 Jackson Labs Technologies Inc J a C k S O n GPSTCXO Eval Board User Manual Labs Figure 3 9 Auxiliary Parameters window L E Paths amp settings FTP Email Coms Time services Auxiiary Aux coms Export graphics Remote control nado nac Ml 2nd port enor request sting SYSTERR lt CR gt T Enable second serial port 2nd port OK prompt scpi lt SPC gt gt lt SPC gt Wildcard for any character type is 7 Wildcard for numeric character is Camiage retum is 2nd port emor prompt E H gt lt SPC gt lt CRx Linefeed is lt LF gt Aux request string meas curent lt CR gt M Log Axl or Log Max SS Aux2 request string FHDATAET7 lt CR gt F Log Aux2 or Log MinSS Aux3 request string DATAE4 lt CR gt I Log Aux3 r Tra
41. se DAC that controls the EFC The GPSTCXO eval board control loop automatically adjusts this setting The user should not have to change this value This command has the following format SERVo COARSeDac lt int gt 0 225 4 9 2 SERVo DACGain This command is used for factory setup 4 9 3 SERVo EFCScale Controls the Proportional part of the PID loop Typical values are 0 7 double oven OCXO to 6 0 simple single oven OCXO Larger values increase the loop control at the expense of increased noise while locked Setting this value too high can cause loop instabilities 36 2011 Jackson Labs Technologies Inc Jackson GPSTCXO Eval Board User Manual Labs This command has the following format SERVO EFCScale lt float gt 0 0 500 0 4 9 4 SERVo EFCDamping Sets the Low Pass filter effectiveness of the DAC Values from 2 0 to 50 are typically used Larger values result in less noise at the expense of phase delay This command has the following format SERVo EFCDamping lt float gt 0 0 4000 0 4 9 5 SERVo SLOPe The parameter determines the sign of the slope between the EFC and the frequency variation of the OCXO This parameter should be set to match your OCXO s EFC frequency slope This command has the following format SERVo SLOPe lt NEG POS gt 4 9 6 SERVo TEMPCOmpensation This command is not supported in the GPSTCXO eval board and is set to 0 0 by default SERVo TEMPCOmpensation lt float gt 4000 0
42. te Sats Visible Sats Tracked Lock State Health Status Please see the SYNChronization command for detailed information on how to decode the health status indicator values Note health status information is available with firmware versions 0 913 and later The Lock State variable indicates one of the following states Value State 0 OCXO warmup 1 Holdover 2 Locking OCXO training 4 Value not defined 5 Holdover but still phase locked stays in this state for about 100s after GPS lock is lost 6 Locked and GPS active 4 9 11 SERVO This command returns the result of the following gueries 38 SERVo COARSeDac SERVo DACGain SERVo EFCScale SERVo EFCDamping SERVo SLOPe SERVo TEMPCOmpensation 2011 Jackson Labs Technologies Inc J a C k S O n GPSTCXO Eval Board User Manual Labs SERVo AGINGcompensation SERVo PHASECOrrection SERVo 1PPSoffset SERVo TRACe 2011 Jackson Labs Technologies Inc 39 GPSTCXO Eval Board User Manual 40 Jackson a O 2011 Jackson Labs Technologies Inc Jackson FireFly 1A User Manual Labs Certification and Warranty 5 0 1 Warranty This Jackson Labs Technologies Inc hardware product is delivered for evaluation purposes only and not for resale or for commercial purposes and no warranty of any kind is given Defective units may be exchanged on a case by case basis and upon the discretion of Jackson Labs Technologies In
43. the software GPSCon This command has the following format SYSTem COMMunicate SERial PROmpt lt ON OFF gt 4 8 1 3 SYSTem COMMunicate SERial BAUD This command sets the RS 232 serial speed The serial configuration is always 8 bit 1 stop bit no parity no HW flow control Upon Factory reset the speed is set at 115200 bauds This command has the following format SYSTem COMMunicate SERial BAUD lt 9600 19200 38400 57600 115200 gt 2011 Jackson Labs Technologies Inc 35 GPSTCXO Eval Board User Manual Jackson Labs 4 8 2 SYSTem STATus This query returns a full page of GPS status in ASCII format The output is compatible with GPSCon 4 8 3 SYSTem FACToryReset ONCE This command applies the Factory Reset setting to the EEPROM All aging tempco and user parameters are overwritten with factory default values 4 9 SERVO Subsystem This subsystem regroups all the commands related to the adjustment of the servo loop SERVo COARSeDac lt int gt 0 225 SERVo DACGain lt int gt 0 1 10000 SERVO EFCScale lt float gt 0 0 500 0 SERVo EFCDamping lt float gt 0 0 4000 0 SERVo SLOPe lt NEG POS gt SERVo TEMPCOmpensation lt float gt 4000 0 4000 0 SERVo AGINGcompensation lt float gt 10 0 10 0 SERVo PHASECOrrection lt float gt 100 0 100 0 SERVo 1PPSoffset lt int gt ns SERVo QUIet lt ON OFF gt SERVo TRACe lt int gt 0 255 SERVo 4 9 1 SERVo COARSeDac This command sets the coar
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