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CSAC GPSDO User Manual - Jackson Labs Technologies, Inc.

1. This query returns the port where the NMEA messages are sent 3 3 6 GPS GPGGA This command instructs the CSAC GPSDO to send the NMEA standard string GPGGA every N seconds with N in the interval 0 255 The command is disabled during the initial 2 minute CSAC warm up phase This command has the following format 2014 Jackson Labs Technologies Inc 27 CSAC GPSDO User Manual Jackson Labs 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 3 3 7 GPS GGASTat This command instructs the CSAC GPSDO 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 2 minute CSAC warm up 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 CSAC performance GGASTat shows height in MSL Meters this is different from traditional GPS receivers that display height in GPS Meters The diffe
2. 3 3 24GPS SURVey STATus 3 3 25GPS INITial DATE lt yyyy mm dd gt 3 3 26GPS INITial TIME lt hour min sec gt 3 3 27GPS JAMlevel 3 3 28GPS FWver 3 3 29GPS i GYRO SUBSYSTEM an 3 4 1 GYRO MODE lt ON OFF gt 3 4 2 GYRO TRACE lt int gt 0 255 3 4 3 GYRO PORT lt RS232 USB gt 3 4 4 GYRO PORT 3 4 5 GYRO CAL lt float float float float float float gt 3 4 6 GYRO CAL COMPUTE 3 4 7 GYRO SENS and GPS CAL RESET 3 4 8 GYRO GLOAD PTIME Subsystem 3 5 1 PTIMe DATE 3 5 2 PTIMe TIME ae 3 5 3 PTIMe TIME STRing 3 5 4 PTIMe TINTerval 3 5 5 PTIME OUTput lt ON OFF gt 3 5 6 PTIMe LEAPsecond 3 5 7 PTIME SYNChronization Subsystem oe a 3 6 1 SYNChronization HOLDover DURation 3 6 2 SYNChronization HOLDover INITiate 3 6 3 SYNChronization HOLDover RECovery INITiate 3 6 4 SYNChronization SOURce MODE Lae E 3 6 5 SYNChronization SOURce STATE 3 6 6 SYNChronization TINTerval 3 6 7 SYNChronization IMMEdiate 3 6 8 SYNChronization FEEstimate 3 6 9 SYNChronization LOCKed 3 6 10SYNChronization OUTput 1 PPs RESET lt ON OFF 3 6 11SYNChronization O0UTput 1PPs RESET 3 6 12SYNChronization OUTput FILTer lt ON OFF gt 3 6 13SYNChronization OUT put FILTer 3 6 14SYNChronization HEAIth 3 6 15SYNChronization TINTerval THReshold 150 2000 3 6 16SYNChronization DIAGnostic Subsystem 3 7 1 DIAGnostic ROSCillator EFControl
3. 2010 17 13 56 23h 46m Allan Deviation Oy T Symmetricom 5125A W 500 Hz j EH 10 1 100 101 106 Averaging Time t seconds Input 10 0 MHz 13 dBm Reference IN REF 18 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs Figure 2 15 shows that the Allan Deviation of the free running unit GPS holdover no GPS antenna is attached is quite good approaching 5E 012 over 100 000 seconds in this typical plot Figure 2 15 Allan Deviation of free running CSAC D3 Jul 2010 21 24 41 Symmetricom5125A dd 3h Allan Deviation oy t To 1 ms NEQ BW 500 Hz 10 14 10 15 10 16 10 3 10 2 10 17 100 101 102 103 104 105 106 Averaging Time 7 seconds Input 10 0 MHz 13 dBm Reference IN REF 2014 Jackson Labs Technologies Inc 19 CSAC GPSDO User Manual Jackson Labs As shown in Figure 2 16 the Phase Noise of the CSAC GPSDO unit with the Phase Noise filter disabled shows a higher baseline noise with a floor of about 145dBc Hz and numerous spurs Figure 2 16 Phase Noise of the CSAC GPSDO with the phase noise filter disabled 14 Sep 2010 21 46 31 2h 7m t Phase Noi
4. 3 1 GPS SATellite TRAcking COUNt E oe ee ae ee i RO qu OT 3 3 2 GPS SATellite VISible COUNT 27 3 3 3 NMEA Support Dek oe OR Gree eee ae DR 3 3 4 GPS PORT lt RS232 USB gt Pi E a a HA Gb ee ee 027 3 3 5 GPS PORT fe ate a ee AR ee 3 3 6 GPS IGPGGA ug bes 4 4 de eR Hein asa 427 3 3 7 GPS GGASTat s o roa sa a a a 28 3 3 8 GPS GPRMC s s a sti a a a Soa a a oa doa s doe Aoa aow 28 3 3 9 GPS GPZDA 28 3 3 10GPSIGPOSV ss 4 4 des ne de ar E at 4128 3 3 11GPS PASHR o s a m 29 3 3 12GPS XYZSPeed 80 3 3 13GPS DYNAMic MODE koa wg 80 3 3 14GPS DYNAMic MODE 8 Automatic Dynamic Mode Ka ee ew a a ad 3 3 15GPS DYNAMic STATe e md Bon al JO 3 3 16GPS REFerence ADELay lt float gt lt s ns gt E 32767ns s 32767ns1 S e 3 3 17GPS REFerence PULse SAWtooth E EE 3 3 18GPS RESET ONCE goth ah A A ea hoa Ae ae ee CABO 3 3 19GPS TMODe lt ON OFF RSTSURV gt eR D al ae he woe ek al 08 3 3 20GPS SURVey ONCE fads oe d ee 4 Ble 4 6 ABA 3 3 21GPS SURVey DURation lt sec gt 84 2014 Jackson Labs Technologies Inc 1 CSAC GPSDO User Manual 3 4 3 5 3 6 3 8 3 3 22GPS SURVey VARiance lt mm 2 gt 3 3 23GPS HOLD POSition lt cm cm cm gt
5. 3 5 5 to allow automatic time and date synchronization of two units to each other The internal RTC is driven by the highly stable CSAC 10MHz signal and thus has very high accuracy 3 3 26 GPS INITial TIME lt hour min sec gt Firmware revision 0 57 and later adds support for manually setting the time and date in the RTC in the event that no GPS signals are available This command allows setting the internal RTC TIME manually when operating the unit in GPS denied environments This command is compatible to the PTIME OUT ON command described in section 3 5 5 to allow automatic time and date synchronization of two units to each other The internal RTC is driven by the highly stable CSAC 10MHz signal and thus has very high accuracy 3 3 27 GPS JAMlevel Firmware revision 0 57 and later adds support for a GPS signal jamming indicator The GPS receiver will detect and flag jamming interference with levels ranging from 0 no jamming to 255 strong jamming Any level exceeding 50 will cause a SYNC HEALTH 0x800 event to be flagged and the unit to disable the LOCK_OUT_OK signal on connector J1 3 3 28 GPS FWver This command returns the firmware version used inside the GPS receiver itself 3 3 29 GPS This query displays the configuration position speed height and other relevant data of the GPS receiver in one convenient location 3 4 GYRO SUBSYSTEM The following Gyro commands are supported GYRO MODE lt ON OFF gt GYRO TR
6. COM 4 Erase block 2 0x002000 0x002FFF Erase block 3 0x003000 0x003FFF Baud Rate SADO Erase block 4 0x004000 0x004FFF Interface Erase block 5 0x005000 0x005FFF 10 Erase all Flash Code Ad Prot Oscillator MHz 7 Erase blocks used by Hex File Step 3 Hex File Hex File FireFly lA_2 19 hex Modified Unknown more info Verify after programming Fill unused Flash Gen block checksums Execute Your Training or Consulting Partner Embedded Systems Academy www esacademy com IL B Press the Select Device button and the window shown in Figure 4 3 will appear O 2014 Jackson Labs Technologies Inc 55 CSAC GPSDO User Manual Ja ck S on Labs Figure 4 3 Device selection window Flash Magic NON PRODUCTION USE ONLY File ISP Options Tools Help EATA HOLC ARM Cortex LPC900 2 clock 80051 80051 x Technical on line articles about 8051 and X programming www esacademy com fag docs C Expand the ARM7 folder and select the appropriate processor in this case the LPC2368 56 2014 Jackson Labs Technologies Inc J a cks on CSAC GPSDO User Manual Labs Figure 4 4 Expanded device selection window File ISP Options Tools Help DAHIABEVE gt v 4028 LPC2101 LPC2102 LPC2103 4 LPC2104 LPC2105 LPC2106 LPC2109 oo LPC2114 LPC2119 oo LPC2124 SY LPC2129 LPC2131 LPC2132 8 LPC2
7. 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 5 2 Select the correct COM port for your computer and set the baud rate to 115200 parity to None Data Bits to 8 and Stop Bits to 1 Set Flow Control to None Once you have configured the communication parameters press the OK button to close the window 5 4 1 2 Auxiliary parameters After pressing the Options button you can select Auxiliary and set other options or measurements See Figure 5 3 for an example of an auxiliary measurement You will notice that the Aux 1 request string has been set to meas temp lt CR gt and the Log Aux1 box is checked In 60 O 2014 Jackson Labs Technologies Inc Ja ck S on CSAC GPSDO User Manual Labs the area below labeled Traces to be visible on the graph the box Aux 1 is checked and the label CSAC temp has been added Figure 5 2 Setting the communications parameters GPSCon Utility Pro GPSCon COM4 e a 0 006319 RTS CTS 2014 Jackson Labs Technologies Inc 61 CSAC GPSDO User Manual Ja ck S on Labs Figure 5 3 Auxiliary parameters window Paths amp settings FTP Email Coms Time services Autliary Aux coms Export graphics Remote control Prefix to indicate request should be pz 5 5 directed to
8. It returns a percentage value between 100 to 100 42 O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 7 2 DIAGnostic ROSCillator EFControl ABSolute This query returns the Electronic Frequency Control EFC steering value of the CSAC oscillator in parts per trillion 15 012 3 7 3 DIAGnostic LlFetime COUNt This query returns the time since power on of the CSAC oscillator in hours 3 7 4 DIAGnostic Sending the command diag returns the following Relative oscillator setting Absolute oscillator setting Time since power on in hours lifetime An example of the syntax scpi gt diag EFControl Relative 0 025000 EFControl Absolute 5 Lifetime 871 3 8 MEASURE Subsystem The MEASURE subsystem regroups the queries related to parameters that are measured on board the CSAC GPSDO 3 8 1 MEASure TEMPerature Displays the PCB temperature around the CSAC oscillator 3 8 2 MEASure VOLTage Displays the CSAC TCXO steering voltage 3 8 3 MEASure CURRent Legacy SCPI command instead of OCXO current this command displays the internal CSAC temperature 3 8 4 MEASure POWersupply Displays the power supply input voltage O 2014 Jackson Labs Technologies Inc 43 CSAC GPSDO User Manual Jackson Labs 3 8 5 MEASure The MEASure query returns the results of the following four queries MEASure TEMPerature MEASure VOLTage MEASure CURRent MEASure POWersupply 3 9 SYSTEM S
9. a switch into airborne 1g mode Without an appropriate climb descent the unit will remain in Automotive mode The following command returns the setting of the GPS dynamic model GPS DYNAMic MODE The actual state chosen by the firmware for the GPS based on vehicle velocity can be obtained with the command GPS DYNAMic STATe A value between 0 and 7 is then returned depending on vehicle dynamics The dynamic state is always set to STATIONARY if one of the Position Hold Auto Survey stationary modes is selected using the command GPS TMODE as the Position Hold mode setting overrides any dynamic state user setting Settings will be applied immediately to the GPS receiver and are stored in Non Volatile memory 32 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 3 15 GPS DYNAMic STATe This query returns the actual state of the dynamic model chosen by the firmware to be applied to the GPS receiver depending on vehicle velocity It returns a value between 0 and 7 which correspond to one of the dynamic models defined in the Table in section 3 3 14 This state can be different from the user selected Dynamic model mode for two reasons e if the dynamic mode is set to 8 Automatic mode the state will reflect the dynamic model being applied to the GPS receiver depending on actual vehicle dynamics e if the GPS Timing Mode is set to ON or to RSTSURV the dynamic state will always be set to 1 Statio
10. low power mode enable 0x0040 Reserved 0x0080 Reserved 3 11 6 CSAC CONTrast This query returns the indication of signal level typically 4000 when locked and 0 when unlocked 3 11 7 CSAC LASer This query returns the current in mA driving the laser 3 11 8 CSAC TCXO This query returns the TCXO Tuning Voltage 0 2 5 VDC tuning range 10 ppm 3 11 9 CSAC SIGnal This query returns the indication of signal level 3 11 10 CSAC HEATpackage This query returns the Physics package heater power typically 15mW under NOC 3 11 11 CSAC TEMP This query returns the Temperature measured by the CSAC unit in C absolute accuracy is 2 C 3 11 12 CSAC FWrev This query returns the Firmware version of the CSAC unit O 2014 Jackson Labs Technologies Inc 51 CSAC GPSDO User Manual Jackson Labs 3 11 13 CSAC SN This query returns the Serial Number of the CSAC in the form YYMMCSNNNNN where YYMM is the year and month of production and NNNNN is the serialized unit of that month 3 11 14 CSAC LIFEtime This query returns the accumulated number of hours that the CSAC has been powered on since the last factory reset of the CSAC GPSDO board The value is stored in the external NVRAM and updated every hour when the CSAC is powered on 3 11 15 CSAC STeer LATch ONCE This command stores the momentary steering offset into the CSAC internal NVRAM This is done automatically by the firmware once every 24 hours so as n
11. the LCD panel is shown in Figure 2 3 Figure 2 2 LCD display connection M ai muna Zi 204 nae Fee na u U 2 2 2 a n ATEN HP e i S Table 2 4 LCD connector J3 pinout PIN NAME 1 CONTRAST 2 5V 3 GND 4 LCD_RS 5 For factory use only 6 LCD_RDWR 7 For factory use only 8 LCD_ENABLE 9 For factory use only 2014 Jackson Labs Technologies Inc ksony Jac son pia 10 LCD DATA4 11 For factory use only 12 LCD DATAS 13 For factory use only 14 LCD_DATA6 15 For factory use only 16 LCD_DATA7 Figure 2 3 LCD display connections _ 5V LCD DISPLAY CONTRAST J3 w ja LCD RS o ja N LCD RDWR N fa o LCD ENABLE 10 LCD DATA4 12 LCD DATAS 13 14 LCD DATA6 XX XX xx 15 16 LCD_DATA7 MAMA CSAC GPSDO User Manual The Power and Ground symbols in Figure 2 3 are for reference only 5V Power on connector J3 is available to drive the LCD display and its backlight only 2 4 4 1 LCD Key The LCD Key is activated by pressing S1 on the PCB see Figure 2 1 or by grounding J1 pin 5 Momentarily activating the key cycles through the LCD display pages described in Section 2 4 4 2 The LCD page can also be selected with the SYSTem LCD PAGE SCPI command The last pag
12. to commence after a GPS reset as indicated by the red blinking LED 3 3 19 GPS TMODe lt ON OFF RSTSURV gt This command selects the Timing Mode of the GPS 2014 Jackson Labs Technologies Inc 33 CSAC GPSDO User Manual Jackson Labs If the Timing Mode is OFF the GPS will act as a regular GPS This mode has to be chosen if the unit is mobile If the Timing Mode in ON the timing features of the GPS are enabled At power up the Hold position stored in NVRAM will be sent to the GPS and will be used as the reference In order to use this mode the receiver position must be known as exactly as possible Errors in the Hold position will translate into time errors depending on the satellite constellation The Hold position can be set manually by the user or can be the result of a Survey executed by the GPS If the Timing Mode is RSTSURV the GPS will start a Survey every time the unit is powered on and following the Survey the GPS will run with the timing features enabled 3 3 20 GPS SURVey ONCE This command starts a Survey At the end of the Survey the calculated Hold position will be stored in NVRAM The Survey parameters can be set with the command GPS SURVey DURation and GPS SURVey VA Riance 3 3 21 GPS SURVey DURation lt sec gt This command sets the Survey minimal duration 3 3 22 GPS SURVey VARiance lt mm22 gt This command specifies the minimum variance of the average position computed during the Survey Th
13. to the specifications tables for the dc and ac mains voltage requirements and ambient operating temperature range 2014 Jackson Labs Technologies Inc 3 CSAC GPSDO User Manual J a C k S onj Labs 4 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs Quick Start Instructions 2 1 Powering Up the Unit The CSAC GPSDO may be powered from an external 8V to 36V DC source or simply from a standard USB port Both power sources can be connected at the same time The internal USB port provides a convenient way to supply power to the unit as well as establish serial communications to the unit via a standard USB serial link Once serial communications have been established the user can try sending and experimenting with the following useful SCPI commands syst stat gps sync diag meas csac help 2 2 Operating the unit from a PC s USB port 1 Connect a 5V compatible GPS antenna to connector J4 2 Plug in a short USB cable to USB connector U14 Plug the other end into a standard USB outlet Please make sure that the USB cable is no longer than 1 foot as the IR power drop on longer cables may prevent proper operation of the unit No software driver is required when operating under Windows XP 7 8 or later as Windows has the required USB driver already built in Once installed the unit should simply show up as a new Serial Comm Port and the operator may use Hyperterminal TeraTerm GPSCon or an
14. 0 57600 115200 gt 3 9 4 SYSTem FACToryreset ONCE This command applies the Factory Reset setting to the NVRAM All aging tempco and user parameters are overwritten with factory default values 3 9 5 SYSTem ID SN This query returns the serial number of the board 3 9 6 SYSTem ID HWrev This query return the Hardware version of the board 3 9 7 SYSTem LCD CONTrast 0 1 0 This command sets the contrast of the LCD 3 9 8 SYSTem LCD CONTrast This query returns the current contrast of the LCD 3 9 9 SYSTem LCD PAGE 0 8 This command displays the requested page on the LCD Starting with firmware version 0 71 nine different pages are supported as described in Section 2 4 4 2 The following table lists the LCD page numbers and corresponding names Value LCD Page 0 Time Date 1 GPS Position 2 GPS Height 3 CSAC Steering 4 CSAC Status O 2014 Jackson Labs Technologies Inc 45 CSAC GPSDO User Manual Jackson Labs 5 TINT 6 Navigation 7 GPS UTC Time 8 Survey Status 3 9 10 SYSTem LCD PAGE This query returns the current page of the LCD 3 9 11 SYSTem COMMunicate USB BAUD lt 9600 19200 38400 57600 115200 gt This command sets the speed of the serial USB port 3 9 12 SYSTem COMMunicate USB BAUD This query returns the speed of the serial USB port 3 9 13 SYSTem STATus This query returns a full page of GPS status in ASCII format The outpu
15. 134 a Laaman On Line training classes for microcontrollers and embedded networking and Internetworking www esacademy com fag classes D Select the Baud Rate of the Flash Magic utility to be 230 4KB or slower E Set the Oscillator MHz to 10 F Check the box marked Erase blocks used by Hex File Warning Make sure NOT to check the box marked Erase all Flash Code Rd Prot under any circumstances this may erase factory calibration data and the unit will not operate and will have to be returned to the factory Checking this box on the ISP utility will thus void the warranty G Under Step 3 Hex File browse for the hex file that you downloaded in step 4 4 H Go to Step 5 and press Start You will observe the firmware being downloaded to the CSAC GPSDO 4 5 Verifying Firmware Update Remove the jumper from header J2 and power cycle the unit Both LED s should blink During power on the unit sends an ID string out of the serial port at 115200 Baud by default The firmware version can also be queried by sending the IDN command Verify that the firmware version is the version that was downloaded 2014 Jackson Labs Technologies Inc 57 CSAC GPSDO User Manual J a C k S onj Labs 58 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs GPSCon Utility 5 1 Description GPSCon is a program for the monitoring and control of a variety of GPS time a
16. 4 Antenna GPS Antenna 5V Amplified Antenna Center RF Input Shield GND MMCX connector OUT_J1 5MHz OUT 5MHz output 5V CMOS Center RF output Shield GND OUT_J2 1PPS OUT 1pps output 5V CMOS Center RF output Shield GND OUT_J3 J6 10MHz OUT 10MHz output Sine wave 13dBm Center RF output Shield GND 3dBm 2 4 2 Harness Connectors J1 and J3 The manufacturer for connectors J1 and J3 is Hirose A mating housing part number for this connector is available from Digikey and crimp pins are also available from Digikey for different wire sizes http search digikey com scripts DkSearch dksus dll Detail amp name H2025 ND The part number of the connectors soldered onto the CSAC GPSDO PCB is Hirose DF11 16DP 2DSA01 2 4 3 Connecting the GPS Antenna Connect the GPS antenna to connector J4 using the BNC to MMCX cable adapter Caution use a Lightning Arrestor on your Antenna setup Use an amplified GPS antenna that is 5V compatible The CSAC GPSDO GPS receiver is a 50 channel high sensitivity GPS receiver with very fast lock time The unit can either be used in stationary applications using the automatic self survey Auto Survey with Position Hold feature or it can be used in mobile platforms Using Position Hold mode improves timing and frequency accuracy especially in GPS challenged antenna locations such as under foliage or with strong multipath signals The CSAC GPSDO is capable of generating standard navigation message
17. 4 Firmware Upgrade Instructions 4 1 Introduction 4 2 ISP Flash Loader Utility Installation s A 4 3 Putting the PCB into In Circuit Programming ISP mode 4 4 Downloading the Firmware 4 4 1 Using the Flash Magic Flash Programming uty 4 5 Verifying Firmware Update i 2014 Jackson Labs Technologies Inc iii CSAC GPSDO User Manual 5 GPSCon Utility 5 1 Description 5 2 Z38xx Utility 5 3 GPSCon Installation 5 4 Using GPSCon 5 4 1 Setting the options 5 4 1 1 Communication Parameters 5 4 1 2 Auxiliary parameters 5 4 1 3 Other options 5 4 2 Sending manual commands to the receiver 5 4 3 Use of the mouse in graph mode 5 4 4 Exporting the graphics Certification and Warranty 6 1 Certification 6 1 1 Warranty 6 1 2 Limitation of Warranty 6 1 3 Exclusive Remedies Jackson O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs Introduction 1 1 Overview The CSAC GPSDO is a game changing disruptive technology culminating from decades of research sponsored by the U S Government It is a breakthrough technology that allows a Cesium Vapor Cell Atomic Reference Oscillator to be packaged in a unit several orders of magnitudes smaller than legacy products with more than an order of magnitude in power reduction versions with less than a total of 0 6W operating power are available and less than 2 minutes warm up to be fully operatio
18. ACE lt int gt 0 255 GYRO PORT lt RS232 USB gt GYRO PORT GYRO CALibrate lt float float float float float float gt GYRO CALibrate COMPute O 2014 Jackson Labs Technologies Inc CSAC GPSDO User Manual 35 CSAC GPSDO User Manual Jackson Labs GYRO CALibrate RESET GYRO SENSitivity lt float float float gt GYRO GLOAD 3 4 1 GYRO MODE lt ON OFF gt Enables or disables electronic compensation This feature must be calibrated at the factory before it can be used 3 4 2 GYRO TRACE lt int gt 0 255 This command sets up the output period of the Accelerometer data in g s per axis and in tilt in Degrees per axis The fastest period is 50ms 20 outputs per second achieved when setting the command to GYRO TRACE 1 The resolution of this command is 1 20 of a second Setting the command to O disables the Accelerometer output This command has the following format GYRO TRACE lt int gt 0 255 GYRO TRACE returns the setting of the period of this command The output of the system is in six floating point numbers the acceleration on the X Y and Z axis in g s and the Tilt of the X Y and Z axis in Degrees 90 to 90 Please note that the Accelerometer has its best resolution and accuracy when the earth s gravitational acceleration is perpendicular to the axis to be measured Thus the sensors accuracy and resolution will be best when the tilt of any axis is around O Degrees The worst performance with an ac
19. Az EEE 15 2 147 Stop 18 7 201 26 4 118 _Hide UTC 22 56 52 28 Oct 2018 LAT N 37 16 52 397 LON W 121 59 15 645 74 16 m HSL OCXO Current OK EFC OK GPS Receiver Status 3D Fix 1PPS SOURCE MODE GPS 1PPS SOURCE STATE GPS GPSDO Status Locked Send 22 39 10 28 10 10 UTC Receiver timeout 3 LOG 3 22 33 20 28 10 10 UTC Receiver timeout Mite DIAG TOG READ L 22 39 29 28 10 10 UTC Receiver timeout ML DIAG ROSC EFC ABS 22 39 39 28 10 10 UTC Receiver timeout O DIAG ROSCEFCREL 22 39 48 28 10 10 UTC Receiver timeout F TitolDIAGTEMP 5 22 33 58 28 10 10 UTC Receiver timeout DIAG TEST RES 22 40 07 28 10 10 UTC Receiver timeout 22 40 23 28 10 10 UTC Receiver timeout Y Log a E Cont EPS INIT DATE lo mo day 22 42 17 28 10 10 UTC Receiver timeout ontil EAU mo GPS INIT POS N deg min sec W deg min sec elev Last error E 5 4 3 Use of the mouse in graph mode Refer to Figure 5 5 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 updat
20. C generated 1PPS with the GPS generated UTC 1PPS phase The CSAC 1PPS phase is allowed to drift up to this threshold before a jam sync is initiated The CSAC phase is slowly and continuously adjusted toward Ons offset to UTC while the phase difference is less than the THReshold phase limit The default setting is 220ns allowing a drift of up to 220ns Reaching this selected threshold will cause a jam sync phase normalization to be initiated which will also cause an indication of the SYNC HEALTH Status of 0x200 to be indicated and the Green LED to be turned off for several minutes 3 6 16 SYNChronization This query returns the results of the following queries SYNChronization SOURce MODE SYNChronization SOURce STATE SYNChronization OUTput 1PPS RESET SYNChronization LOCKed SYNChronization HOLDover STATe SYNChronization HOLDover DURation SYNChronization FEEstimate SYNChronization TINTerval SYNChronization TINTerval THReshold SYNChronization OUTput FILTer SYNChronization HEAIth 3 7 DIAGnostic Subsystem This subsystem regroups the queries related to the diagnostic of the CSAC The list of the commands supported for this subsystem is as follows DIAGnostic ROSCillator EFControl RELative DIAGnostic ROSCillator EFControl ABSolute DIAGnostic LIFetime COUNt 3 7 1 DIAGnostic ROSCillator EFControl RELative This query returns the Electronic Frequency Control EFC output value of the internal reference oscillator
21. CT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY 68 O 2014 Jackson Labs Technologies Inc
22. F gt This command allows the generation of the 1PPS pulse upon power on without an external GPS antenna being connected to the unit By default the unit does not generate a 1PPS pulse until the GPS receiver has locked onto the Satellites With the command SYNC OUT 1PPS RESET ON the unit can now be configured to generate an asynchronous 1PPS output after power on even if a GPS antenna is not connected to the unit Once the GPS receiver locks the 1PPS pulse will align itself to UTC by stepping in 10 equally spaced steps toward UTC alignment The default setting is OFF which means the 1PPS pulse is disabled until proper GPS lock is achieved 40 O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 6 11 SYNChronization OUTput 1PPs RESET This query returns the 1PPS output on reset setting 3 6 12 SYNChronization OUTput FiLTer lt ON OFF gt This command enables disables the Phase Noise filter 3 6 13 SYNChronization OUTput FILTer This query returns the Phase Noise filter setting 3 6 14 SYNChronization HEAlth The SYNChronization HEAlIth 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
23. Jackson N CSAC GPSDO User Manual ocument 80200506 CSAC GPSDO User Manual Copyright O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 1 Introduction 1 1 Overview 1 2 Operating Principles 1 3 General Safety Precautions 1 3 1 Use an approved Antenna Lightning Protector 1 3 2 Grounding 1 3 3 Power Connections 1 3 4 Environmental Conditions D D ND ND 2 Quick Start Instructions 5 2 1 Powering Up the Unit 5 2 2 Operating the unit from a PC s USB port Soe E ee RS ae NS 2 3 Operating the unit from the RS 232 port 6 2 4 Major connections LA Ae Oe A 6 2 4 1 Harness Pinning 8 2 4 2 Harness Connectors J1 and J3 9 2 4 3 Connecting the GPS Antenna 9 2 4 4 Connecting an LCD Display 10 2 4 4 1 LCD Key RAR LL ARR A RR wd SU 2 4 4 2 LCD Display Pages PS GB dee Bw oe eh amp Roe E well 2 5 Loop parameter adjustment 2 16 2 6 Performance graphs 18 3 SCPI Control Quick Start Instructions 25 3 1 Introduction woe Re Mie ass d ae Gh UE ee ae a es RZD 3 2 General SCPI Commands DR at OG ee A E A a LO 32 1 IDN a ee Les e we AE ey O 3 2 2 HELP a ae ars a ga Em a Be A aoe a A AA 3 3 GPS Subsystem D 4 ne SRD ew SR 4 ne 326 3
24. LEAPsecond 3 6 SYNChronization Subsystem This subsystem regroups the commands related to the synchronization of the CSAC GPSDO with the GPS receiver The list of the commands supported for this subsystem is the following SYNChronization HOLDover DURation SYNChronization HOLDover INITiate SYNChronization HOLDover RECovery INITiate SYNChronization SOURce MODE lt GPS EXTernal AUTO gt 38 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs SYNChronization SOURce STATE SYNChronization TINTerval SYNChronization IMMEdiate SYNChronization FEEstimate SYNChronization LOCKed SYNChronization OUTput 1PPS RESET lt ON OFF gt SYNChronization OUTput 1PPs RESET SYNChronization OUTput FILTer lt ON OFF gt SYNChronization OUTput FILTer SYNChronization HOLDover STATe SYNChronization TINTerval THReshold 50 2000 SYNChronization 3 6 1 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 and thus coasting 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 ho
25. O User Manual PASHR POS 0 aa bbbbbb 00 cccc ccccc d eeeee eeeee f ggg 9 g hhhh iii ii jjj jj kkkk kk ILL mm m nn n 00 0 p pp checksum Where aa Number of Sats bbbbbb 00 Time of Day UTC cccc ccccc d Latitude S N eeee eeeee f Longitude W E ggggg gg Antenna Height in meters hhhh Four fixed symbols kkkk k Vertical Velocity in meters s 111 PDOP mm m HDOP nn n VDOP 00 0 Static number p pp Firmware version This command instructs the CSAC GPSDO to send the NMEA standard string PASHR every N seconds with N in the interval 0 255 The command is disabled during the initial 2 minute CSAC warm up phase This command has the following format GPS PASHR lt int gt 0 255 O 2014 Jackson Labs Technologies Inc 29 CSAC GPSDO User Manual Jackson ES 3 3 12 GPS XYZSPeed This command is 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 in the ECEF coordinate system 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 Additionally the number of accrued Leapseconds is indicated in this message which allows proper calculation of GPS time from UTC time as indicated by other messages as well as proper handling of Leap
26. RELative 3 7 2 DIAGnostic ROSCillator EFControl ABSolute 3 7 3 DIAGnostic LlFetime COUNt 3 7 4 DIAGnostic MEASURE Subsystem 3 8 1 MEASure TEMPerature 3 8 2 MEASure VOLTage 3 8 3 MEASure CURRent 3 8 4 MEASure POWersupply O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 8 5 MEASure 3 9 SYSTEM Subsystem 3 9 1 SYSTem COMMunicate SERial ECHO 3 9 2 SYSTem COMMunicate SERial PROmpt 3 9 3 SYSTem COMMunicate SERial BAUD 3 9 4 SYSTem FACToryreset ONCE 3 9 5 SYSTem ID SN a 3 9 6 SYSTem ID HWrev 3 9 7 SYSTem LCD CONTrast 0 1 0 3 9 8 SYSTem LCD CONTrast 3 9 9 SYSTem LCD PAGE 0 8 3 9 10SYSTem LCD PAGE 3 9 11SYSTem COMMunicate USB BAUD lt 9600 11 19200 he 38400 57600 ol 115200 gt 3 9 12SYSTem COMMunicate USB BAUD 3 9 13SYSTem STATus 3 10SERVO Subsystem 3 10 1SERVo DACGain 3 10 2SERVo EFCScale 3 10 3SERVo EFCDamping 3 10 4SERVo TEMPCOmpensation 3 10 5SERVo AGINGcompensation 3 10 6SERVo PHASECOrrection 3 10 7SERVo 1PPSoffset 3 10 8SERVo TRACe 3 10 9SERVo 3 11CSAC Subsystem 3 11 1CSAC RS232 3 11 2CSAC STeer 3 11 3CSAC STATus 3 11 4CSAC ALarm 3 11 5CSAC MODE 3 11 6CSAC CONTrast 3 11 7CSAC LASer 3 11 8CSAC TCXO 3 11 9CSAC SIGnal 3 11 10CSAC HEATpackage 3 11 11CSAC TEMP 3 11 12CSAC FWrev 3 11 13CSAC SN 3 11 14CSAC LIFEtime 3 11 15CSAC STeer LATch ONCE 3 11 16CSAC
27. TO CONFUSE APPLYING POWER TO LCD CONNECTOR J3 WILL SEVERELY DAMAGE THE BOARD The unit will now lock to GPS Red LED is blinking when satellites are being received and will indicate proper lock when the Green LED goes on Once the green LED is on the unit will output 10MHz and 5MHz on the outputs with significantly better than 1ppb frequency accuracy Please note that the GPS receiver establishes the internal antenna gain right after power on so for proper operation the GPS antenna should always be connected prior to turning on the power supply 2 4 Major connections The major connections and features of the CSAC GPSDO PCB are shown in Figure 2 1 6 2014 Jackson Labs Technologies Inc Jackson 7 Figure 2 1 gt a a 3 4 3 a Hii Cesi Atom Clock SN 221900085 CSAC GPSDO User Manual Major connections and features of the CSAC GPSDO LCD Panel A em pa 8V to 36V Power RS232 090 00218 001 aor MIE LUE O01 LL OR LORIE EE a SN 1004CS00011 ER b y Antenna In a D PAGE and USB Communication and Power D iii a E o Y 2 1 z a Table 2 1 shows the functions supported on connector J1 Table 2 1 Connector J1 pinout MHz Out CMOS 5Vpp Ref Name Function Specification J1 1 ISP Enter ISP mode GND pin 1 to activate J1 2 RST_IN Reset the instrument GND pin 2 to activate J1 5 LCD_KEY Cycle through the LCD GND momentarily to cy
28. The Source Mode command allows an optional external 3 3V CMOS 5V CMOS or TTL level 1PPS input to be connected to the CSAC GPSDO board on connector harness J1 The unit can use this external 1PPS input instead of the internal GPS generated 1PPS Switching to the external 1PPS is either done manually with the EXT command option or automatically with the AUTO command option in case the GPS receiver goes into holdover mode for any reason The command has the following format SYNChronization SOURce MODE lt GPS EXTernal AUTO gt 3 6 5 SYNChronization SOURce STATE This query shows the state of the external 1PPS synchronization option 3 6 6 SYNChronization TINTerval This query returns the difference or timing shift between the CSAC GPSDO 1PPS and the GPS 1PPS signals The resolution is 1E 10 seconds 3 6 7 SYNChronization IMMEdiate This command initiates a near instantaneous alignment of the GPS 1PPS and Receiver output 1PPS To be effective this command has to be issued while not in holdover 3 6 8 SYNChronization FEEstimate This query returns the Frequency Error Estimate similar to the Allan Variance using a 1000s measurement interval and comparing the internal 1PPS to GPS 1PPS offset Values less than 1E 012 are below the noise floor and are not significant 3 6 9 SYNChronization LOCKed This query returns the lock state 0 OFF 1 ON of the PLL controlling the CSAC 3 6 10 SYNChronization OUTput 1PPs RESET lt ON OF
29. User Manual Jackson Labs 3 5 3 PTIMe TIME STRing This query returns the current 24 hour time suitable for display for example 13 24 56 3 5 4 PTIMe TINTerval This query is equivalent to the command synchronization TINTerval 3 5 5 PTIME OUTput lt ON OFF gt Firmware revision 0 57 and later adds support for auto initialization of time and date between to Jackson Labs Technologies Inc GPSDO units This allows connecting two units together through the serial port with a null modem cable and having the master unit send time and date information to the slave unit The slave unit s 1PPS reference input can also be driven by the master unit s 1PPS output signal by setting the slave unit to external 1PPS sync mode using the sync sour mode ext command This allows time synchronization at the nanosecond level between two units which can be useful when operating in GPS denied environments Sending the command PTIM OUT ON will cause the unit to automatically generate GPS INIT DATE and GPS INIT TIME sentences on the serial port once per second 3 5 6 PTIMe LEAPsecond This command will return the internally applied leapsecond offset between GPS time and UTC time as stored in the EEPROM GPS Almanac not received yet or as indicated by the GPS receiver GPS Almanac is available 3 5 7 PTIME This query returns at once the result of the three following queries PTIME DATE PTIME TIME PTIME TINTerval PTIME OUTput PTIME
30. almanac predicts should be visible given date time and position 3 3 3 NMEA Support The following five commands allow the CSAC GPSDO to be used as an industry standard navigation GPS receiver The GPGGA GPGSV GPRMC PASHR and GPZDA 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 CSAC GPSDO RS 232 interface Once enabled CSAC GPSDO will send out information on the RS 232 transmit pin automatically every N seconds All incoming RS 232 commands are still recognized by CSAC GPSDO since the RS 232 interface transmit and receive lines are completely independent of one another Please note that the position direction and speed data is delayed by one second from when the GPS receiver internally reported these to the CSAC GPSDO 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 3 3 4 GPS PORT lt RS232 USB gt This commands specifies the communication port where the NMEA messages will be sent 3 3 5 GPS PORT
31. and out 1 3 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 3 1 Use an approved Antenna Lightning Protector The use of an approved and properly grounded antenna lightning protector on the GPS antenna is required to prevent damage injury or death in case of a lightning strike 1 3 2 Grounding To avoid damaging the sensitive electronic components in the CSAC GPSDO 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 i e the GPS antenna 2 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 1 3 3 Power Connections Make sure to connect the DC power to the device following the polarity indicated in Section 2 4 1 3 4 Environmental Conditions This instrument is intended for indoor use The use of a properly installed GPS Antenna Lightning Protector is required It is designed to operate at a maximum relative non condensing humidity of 95 and at altitudes of up to 50 000 meters Refer
32. cle pages Initiate LCD pages GND for more Auto Survey Wired in than 8 seconds to initiate paralell with switch S1 Auto Survey J1 7 LOCK_OK_OUT Indicates that no 3 3V CMOS output can drive internal events are up to 5mA series terminated pending the hardware by 33 Ohms is ok and the CSAC is locked to GPS J1 8 RX_232 RS 232 receive data RS 232 level 2014 Jackson Labs Technologies Inc CSAC GPSDO User Manual Jackson Labs J1 9 TX_232 RS 232 transmit data RS 232 level J1 10 GPS_RS232 Raw NMEA output RS 232 level from GPS receiver in RS 232 level format J1 11 PPS_IN External alternate TTL 3 3V and 5V CMOS 1PPS input compatible J1 13 ALARM Wired in paralell to the 3 3V CMOS level can drive Red LED blinks up to 5mA series terminated whenever a 1PPS by 33 Ohms pulse is received 2 4 1 Harness Pinning PIN NAME 1 ENTER_ISP 2 RST_IN 3 GND 4 GND 5 LCD_KEY 6 GND 7 LOCK_OUT_OK 8 RX RS 232 9 TX RS 232 10 GPS_RS232 11 PPS_IN 12 GND 13 ALARM 14 GND 15 28V 16 28V Table 2 2 is a table of the cable harness J1 pinout Table 2 2 J1 pinout O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs Table 2 3 Miscellaneous connectors Ref Name Function Specification Pinning J2 ISP RESET ISP RESET jumper GND pin 1or 3 to activate J2 1 ISP J2 2 GND J2 3 RST J
33. commands that return antenna height the legacy Fury GPSDO uses GPS height The NMEA position fixes are in the WGSS4 coordinate system while the X Y and Z velocity vectors are given in the ECEF coordinate system 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 TRAcking COUNt GPS S ATellite VISible COUNt GPS PORT lt RS232 USB gt GPS PORT GPS GPGGA lt int gt 0 255 GPS GGASTat lt int gt 0 255 GPS GPRMC lt int gt 0 255 GPS GPZDA lt int gt 0 255 GPS GPGSV lt int gt 0 255 GPS PASHR lt int gt 0 255 GPS XYZSPeed GPS DYNAMic MODE lt int gt 0 7 GPS DYNAMic MODE 8 Automatic Dynamic Mode GPS DYNAMic MODE GPS DYNAMic STATe GPS REFerence ADELay lt float gt lt s ns gt 32767ns 32767ns GPS REFerence PULse SAWtooth GPS RESET ONCE GPS TMODE lt ON OFF RSTSURV gt GPS SURVey ONCE GPS SURVey DURation lt sec gt GPS SURVey VARiance lt mm 2 gt GPS HOLD POSition lt cm cm cm gt GPS SURVey STATus GPS INITial DATE lt yyyy mm dd gt GPS INITial TIME lt hour min sec gt GPS JAMlevel O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs GPS FWver GPS 3 3 1 GPS SATellite TRAcking COUNt This query returns the number of satellites being tracked 3 3 2 GPS SATellite ViSible COUNt This query returns the number of satellites PRN that the
34. curacy of only 5 Degrees is when any of the axis are at their 90 Degree angles this is due to the fact that a SIN g load calculation is done to generate the output normalized to Degrees and the vector is thus least sensitive at 90 Degree angles Acceleration can be measured with up to 3g range on all three axis Please note that since the tilt angle is calculated from the acceleration vectors using gravity that the tilt angles will actually exceed 90 Degrees when acceleration greater than 1g is applied 3 4 3 GYRO PORT lt RS232 USB gt This commands specifies the communication port where the GYRO traces will be sent 3 4 4 GYRO PORT This query returns the port where the GYRO traces are sent 3 4 5 GYRO CAL lt float float float float float float gt Similar to the GPS GYRO CAL command Used to manually calibrate the gain and offset of the Accelerometer output Please see the GPS GYRO CAL command for details See also the GYRO CAL COMPUTE command for a semi automated calibration method 36 O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 4 6 GYRO CAL COMPUTE This command can be used to automatically compute the offset and gain compensation of the accelerometer output for units that are not factory calibrated The goal is to have the unit indicate a range of 1 0g on all three axis when slowly rotated through the axis as well as 0 0g for any axis that is perpendicular to
35. e displayed is remembered in NVRAM and will be shown upon power up Activating the key for 8 seconds initiates the Auto Survey and starting with firmware version 0 71 switches the LCD to the Survey status display page The Auto Survey can also be initiated with the GPS SURVey ONCE SCPI command 2 4 4 2 LCD Display Pages Following are the LCD display pages 2014 Jackson Labs Technologies Inc 11 CSAC GPSDO User Manual J a C k S onj Labs Time Date Figure 2 4 This page shows the time date number of tracked Satellites and the lock status PH Position Hold mode Figure 2 4 Time Date display page e GPS Position Figure 2 5 This page shows the GPS coordinates of the antenna position Figure 2 5 GPS position display page e GPS Height Figure 2 6 This page shows the height in MSL of the GPS antenna as well as the operating mode HOLD Position Hold mode 12 O 2014 Jackson Labs Technologies Inc J a C k S onj CSAC GPSDO User Manual Labs Figure 2 6 GPS height display page e CSAC Steering Figure 2 7 This page shows the internal ALARM indication of the CSAC oscillator itself 0x0 indicates normal operation Also shows the CSAC Oscillator steering offset required to maintain UTC lock which is normalized to 1E 012 offsets The CSAC steering offset is programmed into the CSAC oscillator NVRAM once every 24 hours at which point the offset is set to 0 again This allows the CSAC oscillator to power on
36. e 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 O 2014 Jackson Labs Technologies Inc 63 CSAC GPSDO User Manual J a C k S onj Labs 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 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
37. ency and phase errors are thus present in the CSAC To calibrate these errors out and achieve phase lock to USNO UTC the CSAC GPSDO uses a GPS receiver to generate a highly accurate though unstable 1PPS signal and this 1PPS signal is compared with a 1PPS signal generated by the CSAC 10MHz VCXO The VCEL is digitally tuned to shift the frequency up or down slightly and very slowly to keep the CSAC 1PPS reference in phase lock with the GPS generated 1PPS signal This allows a very close tracking of the U S USNO UTC 1PPS signal to within tens of nanoseconds anywhere in the world out performing even the best free running Atomic References in the long run With this software PLL system the short term instability of the GPS receiver is filtered by the CSAC while the CSAC s long term drift is removed by the GPS receiver resulting in both a very good short term as well as USNO phase locked long term performance The 10MHz VCXO used in the CSAC oscillator exhibits phase noise and numerous spurs on the output of the CSAC A dedicated crystal phase noise cleanup oscillator is phase locked to the CSAC 10MHz output with less than 8Hz loop bandwidth which allows the removal of excessive phase noise and spurs from the CSAC output With this filter Phase Noise performance is improved typically by 10dB and more above 8Hz offset from the carrier and spur performance is improved significantly Software commands allow the cleanup phase noise filter to be switched in
38. g 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 Estimate Sats Visible Sats Tracked Lock State Health Status Please see the SYNChronization HEAIth command for detailed information on how to decode the health status indicator values The Lock State variable indicates one of the following states Value State 0 CSAC warmup 1 Holdover 2 Locking CSAC 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 3 10 9 SERVo This command returns the result of the following queries SERVo DACGain SERVo EFCScale SERVo EFCDamping SERVo TEMPCOmpensation SERVo AGINGcompensation SERVo PHASECOrrection SERVo 1PPSoffset SERVo TRACE 0 3 11 CSAC Subsystem The following commands are used to query the microcontroller built into the CSAC oscillator itself 48 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 11 1 CSAC RS232 This query returns the state OK or FAIL of the serial communication between the main CPU and the CSAC internal microcontroller When the state is FAIL there is a comm
39. hanism to track the health of the CSAC oscillator Excessively high values that appear from one day to the next could be an indicator of failure on the board This coefficient is automatically computed and adjusted over time by the Jackson Labs Technologies Inc firmware This command has the following format SERVo TEMPCOmpensation lt float gt 4000 0 4000 0 3 10 5 SERVo AGINGcompensation This parameter is a coefficient that represents the drift of the EFC needed to compensate the natural drift in frequency of the CSAC 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 3 10 6 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 500 0 500 0 3 10 7 SERVo 1PPSoffset This command sets the CSAC GPSDO 1PPS signal s offset to UTC in 100ns 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 2014 Jackson Labs Technologies Inc 47 CSAC GPSDO User Manual Jackson Labs 3 10 8 SERVo TRACe This command sets the period in seconds for the debug trace Debu
40. he SCPI Standard Commands for Programmable Instrumentation subsystem by using a host system terminal program such as TeraTerm or Hyperterminal By default the terminal settings are 115200 8N1 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 return a list of all the available commands for the CSAC 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 for details regarding individual SCPI command definitions A basic familiarity with the SCPI protocol is recommended when reading this chapter As a Quick Start the user may want to try sending the following commands to one of the serial interfaces syst stat help gps sync diag 3 2 General SCPI Commands 3 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 O 2014 Jackson Labs Technologies Inc 25 CSAC GPSDO User Manual Jackson Labs 3 2 2 HELP This query returns a list of the commands available for the CSAC GPSDO 3 3 GPS Subsystem 26 Note Please note that CSAC GPSDO displays antenna height in MSL Meters rather than in GPS Meters on all
41. 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 O 2014 Jackson Labs Technologies Inc 59 CSAC GPSDO User Manual 5 4 1 Setting the options Jackson a To set up the options for your GPSCon session press the Options button below the display area The window shown in Figure 5 1 will appear You can select from the tabs which options you wish to set Figure 5 1 Options window GPSCon Utility Pro GPSCon COM A A j sae Time Ma p Graph Export Help About r Logging and graph Max kB 0 unlimited Interval 30 secs r Local HTML and image files Bit from display bitmap Pixels 317 HTML update interval 30 HTML file c program files amp 86 gpscon gpsstat htm Browse Rico Satellite tracking history file Max ax kB 0 unlimited 512 Track file c program files amp 86 gpscon gpsdmp bin Browse mins 5 4 1 1 Communication Parameters Paths amp settings FTP Email Coms Time services Auvdliary Aux coms Export graphics Remote control IV Log Status IV Log EFC IV Log sat count M Tito GPS F Log PU M Translate time codes 7 Continuously read error queue Fash LED M Use bitmap M Statistics M Show best fit to EFC T ANSI font in status FF Timax g ns Filter coeff 0 025 Before you can use
42. ious products such as the FireFly IIA GPSDO units which did not support Position Hold Auto Survey modes 4 GPS DYNAMic MODE 8 Automatic Dynamic Mode Automatic Dynamic Mode allows the CSAC GPSDO firmware to automatically configure the GPS receiver Kalman filter parameters based on actual mission velocities and motion profiles The unit will try to set the GPS receiver to the optimal settting for any given velocity The unit is able to set 7 different modes as shown in section 3 3 13 The following table shows the Dynamic mode the unit will program into the GPS receiver when Automatic Mode is selected Dynamic Mode 8 O 2014 Jackson Labs Technologies Inc 31 CSAC GPSDO User Manual Jackson Labs Velocity Threshold Selected Dynamic Model Fallback to lower setting 0 2 knots Stationary none gt 2 knots Pedestrian lt 1 knots gt 10 knots Automotive lt 8 knots gt 60 knots and gt 400 Feet min Airborne 1g lt 50 knots climb descent gt 150 knots Airborne 2g lt 130 knots gt 240 knots Airborne 4g lt 210 knots In this Automatic mode the unit will configure the GPS based on the actual vehicle velocity Please note that in order to switch from the Automotive mode into the first Airborne 1g mode both a vehicle velocity greater than 60 knots as well as a climb descent rate greater than 400 feet per minute are required Alternatively a vehicle velocity of greater than 100 Knots will also initiate
43. is minimum value is used as a threshold under which the GPS can stop the Survey The GPS will stop the Survey when the minimal duration has been reached and the variance of the average position is under the specified minimum variance 3 3 23 GPS HOLD POSition lt cm cm cm gt This command allows the user to specify manually the exact position of the antenna This command will overwrite the Hold position in NVRAM Subsequent Survey will overwrite also the Hold position The Hold position is stored in ECEF coordinates 3 3 24 GPS SURVey STATus This query displays the current status of the survey The status of the survey is in one of the 3 states ACTIVE a survey is in progress VALID a survey has been achieved successfully and the GPS is now using this Hold position as reference INVALID no survey are in progress or have been achieved since the last power cycle When in ACTIVE or VALID state this query will also display the duration the Hold position in ECEF coordinates and the position variance 34 O 2014 Jackson Labs Technologies Inc ksony Jac son ia 3 3 25 GPS INITial DATE lt yyyy mm dd gt Firmware revision 0 57 and later adds support for manually setting the time and date in the RTC in the event that no GPS signals are available This command allows setting the internal RTC DATE manually when operating the unit in GPS denied environments This command is compatible to the PTIME OUT ON command described in section
44. ldover The second number in the response identifies the holdover state A value of O indicates the Receiver is not in holdover a value of 1 indicates the Receiver is in holdover 3 6 2 SYNChronization HOLDover INITiate The SYNC HOLD INTT and SYNC HOLD REC INIT commands allow the user to manually enter and exit the holdover state even while GPS signals are still being properly received This forced holdover allows the unit to effectively disable GPS locking while still keeping track of the state of the 1PPS output in relation to the UTC 1PPS signal as generated by the GPS receiver When the unit is placed into forced holdover with this command the unit will indicate the time interval difference between the 1PPS output and the GPS UTC 1PPS signal by using the SYNC TINT command This allows the user to see the CSAC drift when not locked to GPS for testing purposes or to prevent the GPS receiver from being spoofed and affecting the CSAC frequency accuracy All other frequency disciplining functions of the unit will behave as if the GPS antenna was disconnected from the unit while in this forced holdover state 3 6 3 SYNChronization HOLDover RECovery INITiate This command will disable the forced holdover state see the SYNC HOLD INIT command The unit will resume normal GPS locking operation after this command has been sent O 2014 Jackson Labs Technologies Inc 39 CSAC GPSDO User Manual Jackson Labs 3 6 4 SYNChronization SOURce MODE
45. lue 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 O 2014 Jackson Labs Technologies Inc 65 CSAC GPSDO User Manual J a C k S onj Labs 66 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs Certification and Warranty 6 1 Certification Jackson Labs Technologies Inc certifies that this product met its published specifications at time of shipment 6 1 1 Warranty This Jackson Labs Technologies Inc hardware product is warranted against defects in material and workmanship for a period of 1 one year from date of delivery During the warranty period Jackson Labs Technologies Inc will at its discretion either repair or replace products that prove to be defective Jackson Labs Technologies Inc does not warrant that the operation for the software firmware or hardware shall be uninterrupted or error free even if the product is operated within its specifications For warranty service this product must be returned to Jackson Labs Technologies Inc or a service facility designated by Jackson Labs Technologies Inc Customer shall prepay shipping charges and shall pay all duties and taxes for products returned to Jackson Labs Technologies Inc for warranty ser
46. nal while out performing many industry standard Atomic Oscillators The unit is available with a temperature range of 40 C to 85 C and greater than 100 000 hours MTBF The CSAC oscillator provides an impressive frequency accuracy long term stability and fast lock with low power consumption Through hardware and firmware support the Jackson Labs Technologies Inc CSAC GPSDO improves the phase noise performance of the unit and adds an isolated distribution amplifier with four output channels at 10MHz The CSAC GPSDO provides LCD RS 232 and USB serial links for command and control as well as an aviation bus compatible power supply that operates from 8V up to 36V with reverse polarity and over voltage protection and can thus be directly connected to an aircraft s 12V or 24V power bus For long term Stratum 1 frequency accuracy and constant calibration the CSAC GPSDO includes an extremely high performance GPS receiver that can acquire and track up to 50 GPS signals down to a state of the art 160dBm a 32 bit processor that runs a Real Time OS a low noise 1OMHz distribution amplifier with four highly Isolated 1OMHz Sine Wave outputs one 5MHz CMOS output one 1PPS UTC synchronized CMOS output RS 232 and USB control interfaces and a generic LCD interface The CSAC GPSDO also includes a high performance time interval counter that can measure the internally generated 1PPS signal from the GPS receiver or an externally supplied 1PPS reference sig
47. nal with a resolution of 20 picoseconds The CSAC oscillator is phase locked to either of these two 1PPS signals with better than 0 3ns average phase accuracy typically Software compensation measures residual aging thermal and g sensitivity errors of the CSAC oscillator and applies electronic compensation to reduce these residual errors This error compensation can improve performance especially in GPS denied environments and allows monitoring of the CSAC health and detection of performance abnormalities in the system Generic NMEA and SCPI GPIB commands on two serial interfaces allow very fast integration into legacy applications and by using the NMEA serial strings the unit can behave like a standard GPS receiver albeit with better than 1 meter horizontal accuracy typically and full WAAS EGNOS MSAS SBAS support 2014 Jackson Labs Technologies Inc 1 CSAC GPSDO User Manual Jackson Labs 1 2 Operating Principles A Cesium Vapor Cell is excited from a VCEL Laser source The VCSEL is modulated at 4 6 GHz to produce a complementary pair of sidebands separated by the cesium ground state hyperfine frequency of 9 2 GHz As Cesium supply depletion is not a lifetime limiting factor in the CSAC the CSAC GPSDO implementation allows operational lifetimes that potentially exceed those of Cesium beam standards by far The Hyperfine transition frequency of the Cesium Vapor cell is affected by adverse environmental influences and long term frequ
48. nary 3 3 16 GPS REFerence ADELay lt float gt lt s ns gt 32767ns 32767ns The ADELay command allows bi directional shifting of the 1PPS output in relation to the UTC 1PPS reference in one nanosecond steps This allows antenna cable delay compensation as well as retarding or advancing the 1PPS pulse arbitrarily Typical antenna delays for a 30 foot antenna cable with 1 5ns per foot propagation delay would be compensated with the following command GPS REF ADEL 45ns This command can be used to fine tune different units to have co incident 1PPS pulse outputs Please note that during normal operation the 1PPS pulse may wander around the UTC 1PPS pulse while the unit is tracking the GPS signals The present offset between the 1PPS output and the UTC 1PPS signal can be queried with the command SYNC TINT and this offset should be taken into account when calibrating two unit s 1PPS outputs to each other since the lock algorithms will try to steer the CSAC for a 0 0ns offset to the UTC 1PPS time pulse 3 3 17 GPS REFerence PULse SAWtooth This command returns the momentary sawtooth correction factor that the GPS receiver indicated 3 3 18 GPS RESET ONCE Issues a reset to the internal GPS receiver This can be helpful when changing the antenna for example since the GPS receiver measures the antenna system s C No right after reset and adjusts its internal antenna amplifier gains accordingly It takes approximately 1 minute for locking
49. nd frequency standard receivers It communicates with the receiver using the SCPI command set 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 Try running GPSCon in Windows XP compatibility mode and as an administrator If you encounter problems it is recommended that you install GPSCon on a slower computer using Windows XP 5 2 Z38xx Utility If the GPSCon utility is not available you may use the Z38xx utility The Z83XX utility is a PC monitor program for GPS Disciplined References GPSR which communicate using theSCPI Standard Commands for Programmable Instrumentation Protocol It is available on the Jackson Labs Technologies Inc website under the Support tab http www jackson labs com assets uploads main Z38XX_download zip The program provides real time monitoring of the operation of the GPSR including status information GPS satellite information timing and control information holdover prediction reference Allan Variance and even a UTC clock with second accuracy It also displays various logs and stores all measurements on file for later analysis 5 3 GPSCon Installation Follow the directions that come with GPSCon for installing the utility on your computer 5 4 Using GPSCon The GPSCon utility has a help file that should be consulted
50. nstant oo Input 10 0 MHz 13 dBm Reference IN REF O 2014 Jackson Labs Technologies Inc 21 CSAC GPSDO User Manual Jackson Labs 22 The plot in Figure 2 18 shows the CSAC GPSDO unit s Phase Noise performance as a plot of two superimposed measurements one with the Phase Noise filter enabled and one with the filter disabled The noise improvement and reduction of spurs is clearly visible Phase Noise performance is improved by up to 13dB at 1OKHz offset Figure 2 19 shows an alternate comparative phase noise plot Figure 2 18 Both phase plots superimposed 10MHZ DUT vs 10MHz HP 3048A Carrier 10 E 6 Hz 100 1K Ec dBc Hz O 2014 Jackson Labs Technologies Inc J a ck S on CSAC GPSDO User Manual Labs Figure 2 19 Alternate comparative phase noise plot ganse Z f Phase Noise at 10 0 MHz dBc Hz meme 10 dB Di 60 0 7 HER a 70 0 80 0 90 0 100 0 110 0 120 0 130 0 140 0 150 0 160 0 E RIN II 100 101 102 103 101 105 106 Offset Frequency Hz Time Constant oo Input 10 0 MHz 13 dBm Reference 10 0 MHz 13 dBm O 2014 Jackson Labs Technologies Inc 23 CSAC GPSDO User Manual J a C k S onj Labs 24 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs SCPI Control Quick Start Instructions 3 1 Introduction The CSAC GPSDO has two serial ports that can be used simultaneously for accessing t
51. olorado Figure 2 9 TINT display page e Navigation Figure 2 10 This page displays the following Navigation status Course in degrees Speed knots operating mode and altitude feet 14 2014 Jackson Labs Technologies Inc J a ck S onj CSAC GPSDO User Manual Labs Figure 2 10 Navigation display page toee e GPS UTC Time Figure 2 11 This page displays the following UTC GPS Time information UTC time hh mm ss GPS time hh mm ss and leapsecond offset seconds Figure 2 11 GPS UTC Time display page e Survey status Figure 2 12 This page displays the status NOT ACTIVE ACTIVE or VALID duration seconds and variance mm of the position survey Figure 2 12 Survey status display page O 2014 Jackson Labs Technologies Inc 15 CSAC GPSDO User Manual Jackson Labs 2 5 Loop parameter adjustment All loop parameters can be controlled via the serial ports Loop parameters are optimized for the Atomic Oscillator on the board and changing the factory settings may cause 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 below 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 ty
52. ot to damage the CSAC NVRAM which has a limited number of write cycles The user may force this value to be stored into the CSAC by issuing the CSAC STeer LATch ONCE command 3 11 16 CSAC This query displays all the CSAC queries defined above 52 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs Firmware Upgrade Instructions 4 1 Introduction The following is a short tutorial on how to upgrade the CSAC GPSDO firmware Please follow the instructions in order to prevent corrupting the CSAC GPSDO Flash which may require reflashing at the factory With some practice the entire Flash upgrade can be done in less than one minute even though the following seems like a fairly long list of instructions 4 2 ISP Flash Loader Utility Installation Jackson Labs Technologies Inc recommends using the Flash Magic utility to upgrade the contents of Flash memory on the CSAC GPSDO It is available for download on the Flash Magic website http www flashmagictool com Follow the directions given on the website for installing the utility on your computer Note The Philips LPC2000 utility that is used on other Jackson Labs Technologies Inc products will not support the newer LPC2368 processor used on the CSAC GPSDO 4 3 Putting the PCB into In Circuit Programming ISP mode Momentarily short out pins 1 and 2 of header J2 using a jumper or other conductive material during power on See Figure 4 1 Both LED
53. pical 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 CSAC GPSDO 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 Setting this value too high may cause loop instability A well compensated unit will show performance similar to the plot in Figure 2 13 when experiencing small perturbations 16 O 2014 Jackson Labs Technologies Inc J a C ks on bs CSAC GPSDO User Manual Figure 2 13 CSAC GPSDO phase compensation plot EFC 2 409962 ad 0m sd 0 07 m 3 Current 2 4099 0 075127 28 0 ns Tl av 1 03n sd 4 7 n eee F Client mode Li ES O 2014 Jackson Labs Technologies Inc 17 CSAC GPSDO User Manual J a ck S on Labs 2 6 Performance graphs Figure 2 14 shows the typical Allan Deviation of the CSAC GPSDO unit when locked to GPS ADEV performance approaches 1E 013 per day when locked to GPS The plot shows that at averaging intervals of 1000 seconds and more the GPS disciplining algorithm starts to improve the performance of the CSAC oscillator Figure 2 14 Allan Deviation of CSAC when locked to GPS 10 Sep
54. rence between MSL and GPS height can be significant 35m or more are common 3 3 8 GPS GPRMC This command instructs the CSAC GPSDO to send the NMEA standard string GPRMC every N seconds with N in the interval 0 255 The command is disabled during the initial 2 minute CSAC warm up phase This command has the following format GPS GPRMC lt int gt 0 255 3 3 9 GPS GPZDA This command instructs the CSAC GPSDO to send the NMEA standard string GPZDA every N seconds with N in the interval 0 255 The command is disabled during the initial 2 minute CSAC warm up phase This command has the following format GPS GPZDA lt int gt 0 255 3 3 10 GPS GPGSV This command instructs the CSAC GPSDO to send the NMEA standard string GPGSV every N seconds with N in the interval 0 255 The command is disabled until the GPS receiver achieves a first fix GPS GPGSV lt int gt 0 255 28 2014 Jackson Labs Technologies Inc Jackson 7 3 3 11 GPS PASHR The PASHR command alongside the GPZDA command will give all relevant parameters such as time date position velocity direction altitude quality of fix and more As an example the String has the following data format PASHR POS 0 7 202939 00 37 16 28369 N 12157 43457 W 00087 40 070 01 000 3 1 000 10 05 6 03 5 04 3 00 0 DD00 32 Please note that the length of the string is fixed at 115 characters plus the two binary 0x0d Ox0a termination characters CSAC GPSD
55. results in a single hexadecimal value encoding the following system status information If the phase offset to UTC is gt 250ns HEALTH STATUS 0x4 If the run time is lt 300 seconds HEALTH STATUS I 0x8 If the GPS is in holdover gt 60s HEALTH STATUS l 0x10 If the Frequency Estimate is out of bounds HEALTH STATUS l 0x20 If the short term drift ADEV 100s gt 100ns HEALTH STATUS l 0x100 For the first 3 minutes after a phase reset HEALTH STATUS l 0x200 If the CSAC Oscillator indicates an alarm HEALTH STATUS l 0x400 If the GPS receiver indicates a strong jamming signal HEALTH STATUS l 0x800 of gt 50 range is 0 to 255 As an example if the unit is in GPS holdover and the UTC phase offset is gt 250ns then the following errors would be indicated 1 UTC phase gt 250ns 0x4 2 GPS in holdover 0x10 Oring these values together results in 0x10 0x4 0x14 The unit would thus indicate HEALTH STATUS 0x14 and the Green LED as well as the LOCK_OK output would go off indicating an event is pending 2014 Jackson Labs Technologies Inc 41 CSAC GPSDO User Manual Jackson Labs A health status of 0x0 indicates a properly locked and warmed up unit that is completely healthy 3 6 15 SYNChronization TINTerval THReshold 50 2000 This command selects the internal oscillator 1PPS phase offset threshold as compared to UTC at which point the unit will initiate a counter reset jam sync aligning the CSA
56. s 20 H 2 4r A 159494 Temp E Filter coeff 0 025 Stat Span mins 15000 Stop Hide Not Tracking l PRN El z 15 1 40 na h AN Ay i VTC 1 35 45 16 Now 2010 LaT N 27 15 29 756 LON W 121 57 40 195 7 20 m MSL q Sat count 69 0 ns start 17 27 41 15 11 10 UTC Send serv tar y 18 02 47 15 11 10 UTC Receiver timeout z servitar T Log Status M Log sat count Translate time codes 2584 95 6348 7 66236 0 0054106 4 072305 0 00530379 Log EFC 2414209 Options sepi gt IV Tlto GPS F11E 09 0 158524 I Log PU fl in el Update now D Continuously read error queue Flash LED Last error r 5 4 4 Exporting the graphics 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 TI control A va
57. s see GPS GPGGA GPS GPZDA GPS GPGSV GPS PASHR and GPS GPRMC serial commands that are compatible with most GPS based navigation software These navigation messages may either be sent to the RS 232 serial port or to the USB serial port The GPS receiver generates a 1PPS time signal that is phase synchronized to UTC This 1PPS signal is used to frequency lock the 1OMHz Sine Wave output of the CSAC GPSDO to UTC thus disciplining the unit s Atomic Clock 10MHZ frequency output to the US Naval master clock for very high frequency accuracy typically better than 10 digits of frequency accuracy when locked to GPS Using a high performance Timing GPS receiver allows operation with a phase stability error of typically less than 15 nanoseconds anywhere in the world 2014 Jackson Labs Technologies Inc CSAC GPSDO User Manual J a C k S onj Labs 2 4 4 Connecting an LCD Display 10 An optional industry standard alphanumeric LCD display may be connected to the unit for displaying status information LCD s with 16x2 characters are optimal but 20x2 or 20x4 displays may also work An example low cost display is available from www mouser com Newhaven Display PN NHD 0216K1Z NSW BBW L The connector drives the LCD directly and the 5V pin can also be used to drive the LCD s backlighting Contrast of the LCD is adjusted via software command Figure 2 2 shows the mechanical connections A schematic showing the connections from the CSAC GPSDO to
58. s should remain off indicating the unit is properly placed into ISP mode If the LED s light up after power on the unit is not in ISP mode O 2014 Jackson Labs Technologies Inc 53 CSAC GPSDO User Manual Jackson Labs Figure 4 1 Location of header J2 LALLZCAA Short out pins 1 and 2 fof J2 prior to power LABS S1 Um Atomic Clock SN 22 1090985 Part Number 090 00218 001 DOVE 10 RR LL OL RO RR UII VANI mm 410040500011 Pa cones LL Li 4 4 Downloading the Firmware Download the latest version of CSAC GPSDO firmware from the Jackson Labs Technologies Inc support website and store it in a place that will be remembered The file is in hex format The unit needs to be connected to the computer s RS 232 serial port prior to firmware download Connect a DB 9 serial connector to the CSAC GPSDO as indicated in Section Please note that the unit can only be upgraded through the RS 232 port not through the USB serial port 4 4 1 Using the Flash Magic Flash Programming Utility A Open the Flash Magic utility Set the COM port in the Flash Magic application as needed on your PC Set Interface to None ISP 54 O 2014 Jackson Labs Technologies Inc Ja ck S on CSAC GPSDO User Manual Labs Figure 4 2 Flash Magic programming utility luiaasvE gt vimos Lf Step 1 Communications Select Device LPC2138 Erase block 0 Ox000000 0x000FFF a Erase block 1 0x001000 0x001FFF COM Port
59. se at 10 0 MHz dBc Hz esa 10 dB Div Offset Frequency Hz Time Constant oo Input 10 0 MHz 13 dBm Reference IN REF Beginning in August 2012 and with BOM revision 2 1 the CSAC GPSDO board had a component change that improves the phase noise filter performance significantly especially below 2KHz offsets from the carrier Please see Figure 2 17 for a typical plot of the new phase noise performance of the unit This change also reduces the jitter of the 10MHZ outputs considerably The following plot shows operation with the phase noise filter disabled light trace and enabled darker trace Noise performance improvements by the filter of almost 20dB can be seen at 1KHz offsets over the CSAC oscillator by itself Please contact Jackson Labs Technologies Inc for information on retrofitting older CSAC GPSDO units with this performance improvement 20 O 2014 Jackson Labs Technologies Inc Ja cks on CSAC GPSDO User Manual Labs Figure 2 17 Phase Noise of the CSAC GPSDO with the phase noise filter enabled EPP ane HORS L f Phase Noise at 10 0 MHz dBc Hz Symmetricom51254 10 dB Div 60 0 70 0 160 0 100 101 102 103 104 105 105 Offset Frequency Hz Time Co
60. second events 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 3 3 13 GPS DYNAMic MODE This command allows the user to select the dynamic motion model being applied to the Kalman filters in the GPS receiver This allows for larger amounts of filtering for lower velocity applications effectively reducing noise and multipath interference Applications with high acceleration can now be used with fast filter settings to allow for the most accurate GPS coordinates to be provided in high dynamic applications such as Jet aircraft Doppler tracking is enabled in all airborne modes as Carrier Phase tracking is very difficult to achieve in high velocity applications The GPS will perform Carrier Phase tracking for non airborne modes The command has the following syntax GPS DYNAMic MODE lt int gt 0 8 Sending the following command to the CSAC GPSDO will select a stationary GPS dynamic model for example gps dynam mode 1 The following table lists all available modes Value Model Application Portable Recommended as a default setting Stationary Used in stationary applications Pedestrian Used in man pack pedestrian settings Automotive Vehicular velocity applications 30 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 4 Sea Used on Ships where altitude is expected
61. t is compatible with GPSCon 3 10 SERVO Subsystem This subsystem regroups all the commands related to the adjustment of the servo loop SERVo DACGain lt float gt 0 1 10000 SERVo EFCScale lt float gt 0 0 500 0 SERVo EFCDamping lt int gt 2 4000 SERVo TEMPCOmpensation lt float gt 4000 0 4000 0 SERVo AGINGcompensation lt float gt 10 0 10 0 SERVo PHASECOrrection lt float gt 500 0 500 0 SERVo 1PPSoffset lt int gt ns SERVo TRACe lt int gt 0 255 SERVo 3 10 1 SERVo DACGain This command is used for factory setup 46 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 10 2 SERVo EFCScale Controls the Proportional part of the PID loop Typical values are 0 7 to 6 0 Larger values increase the loop control at the expense of increased noise while locked Setting this value too high can cause loop instabilities This command has the following format SERVo EFCScale lt float gt 0 0 500 0 3 10 3 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 int gt 2 4000 3 10 4 SERVo TEMPCOmpensation This parameter is a coefficient that reflects the correlation between the temperature of the CSAC versus the required frequency steering Monitoring the tempco and aging parameters provides a mec
62. the earth s gravity The user must establish the minimum and maximum g loads that are displayed on all three axis by slowly tilting the unit over 180 Degrees on all three axis These values are written down on a piece of paper and the system calculates the required gain and offset parameters to scale the accelerometer output to 1g peak to peak scale and Og indication based on entering these values The GYRO CAL COMPUTE command will query the user for the maximum and minimum indicated g loads The GYRO TRACE 10 command can be used to help establish the g indications on the three different axis to aid in this calibration 3 4 7 GYRO SENS and GPS CAL RESET Used for factory calibration of Gyro subsystem 3 4 8 GYRO GLOAD This command will return the present acceleration on the X Y and Z axis 3 5 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 DATE PTIMe TIME PTIMe TIME STRing PTIMe TINTerval PTIME OUT put lt onloff gt PTIMe LEAPsecond PTIME 3 5 1 PTIMe DATE This query returns the current calendar date The local calendar date is referenced to UTC time The year month and day are returned 3 5 2 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 2014 Jackson Labs Technologies Inc 37 CSAC GPSDO
63. the second serial port 2nd port error request string FSYST ERR lt CR gt Enable second serial port 2nd port OK prompt Iscpi lt SPC gt gt lt SPC gt Wildcard for any character type is 7 Wildcard for numeric character is Camiage retum is 2nd port error prompt E HtH gt lt SPC gt lt CR gt Linefeed is lt LF gt Aux request string meas temp lt CR gt M Log Axl or Log Max SS Aux2 request string DATAET lt CR gt T Log Aux2 or Log Min SS Aux3 request string DATA E42 lt CR gt T Log Aux3 r Traces to be visible on the graph M EFC Label Mag Offset Hold wT M Ant CSAC templ fi jo E F PU FT Aux2 1023 fo E F Sats 1 AG f jo E 5 4 1 3 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 62 O 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 5 4 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 5 4 Care must be taken when sending these commands so be sure that the command that you select is supported by the CSAC GPSDO Once you ve selected the command you can press Send to send it to the CSAC GPSDO Figure 5 4 Sending manual commands Status Time Map Graph Export Help About VdmLabs Firmware Rev 2 19 A Life fel Not Tracking 3 5 E PRN El
64. to be constant 5 Airborne lt lg Airborne applications with less than 1g acceleration 6 Airborne lt 2g Airborne applications with less than 2g acceleration 7 Airborne lt 4g Airborne applications with less than 4g acceleration 8 Automatic Mode Select one of the above states 0 7 based on the actual velocity of the vehicle 3 3 1 The CSAC GPSDO uses a GPS receiver that is capable of running in a stationary mode with Position Auto Survey called Position Hold Mode This mode increases timing stability by storing the position into memory and solving the GPS signal only for time as the position is not expected to change Two modes can be selected for Auto Survey operation see section 3 3 19 for a description of the GPS TMODE command 1 Manually setting Timing Mode to ON with a hard coded position in NVRAM 2 Enabling Auto Survey to start automatically after power on by setting Timing Mode to RSTSURV If either one of the above two GPS TMODE Auto Survey Position Hold modes is selected the GPS DYNAMIC MODE command is disabled internally and its setting is ignored as the unit does not expect any motion on the antenna In this case the dynamic state as programmed into the GPS receiver is set to STATIONARY independent of the user selection for GPS DYNAMIC MODE The current dynamic state being applied to the GPS receiver can be queried with the command GPS DYNAMIC STATE Please note that this command syntax has changed from prev
65. ubsystem This subsystem regroups the commands related to the general configuration of the CSAC GPSDO 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 FACToryreset ONCE SYSTem ID SN SYSTem ID HWrev SYSTem LCD CONTrast 0 1 0 SYSTem LCD CONTrast SYSTem LCD PAGE 0 8 SYSTem LCD PAGE SYSTem COMMunicate USB BAUD lt 9600 19200 38400 57600 115200 gt SYSTem COMMunicate USB BAUD SYSTem STATus 3 9 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 3 9 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 the software GPSCon This command has the following format SYSTem COMMunicate SERial PROmpt lt ON OFF gt 44 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 9 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 3840
66. unication breakdown and the unit should be power cycled to clear the communication error 3 11 2 CSAC STeer This query returns the current Frequency Adjustment in units of parts per trillion 1E 012 3 11 3 CSAC STATus This query returns the status value in 0 9 as shown below 2014 Jackson Labs Technologies Inc 49 CSAC GPSDO User Manual Alarm 0 I Nn FP D KF 3 11 4 CSAC ALarm Jackson a Definition Locked Microwave Frequency Steering Microwave Frequency Stabilization Microwave Frequency Acquisition Laser Power Acquisition Laser Current Acquisition Microwave Power Acquisition Heater equilibration Initial warm up Asleep ULP mode only This query returns the Alarm value as shown below Alarm 0x0001 0x0002 0x0010 0x0020 0x0040 0x0080 0x0100 0x0200 0x0400 0x0800 0x1000 0x2000 0x4000 50 Definition Signal Contrast Low Synthesizer tuning at limit DC Light level Low DC Light level High Heater Power Low Heater Power High uW Power control Low uW Power control High TCXO control voltage Low TCXO control voltage High Laser current Low Laser current High Stack overflow firmware error 2014 Jackson Labs Technologies Inc Jackson CSAC GPSDO User Manual Labs 3 11 5 CSAC MODE This query returns the CSAC mode as shown below 0x0001 Analog tuning enable 0x0002 Reserved 0x0004 Reserved 0x0008 1 PPS auto sync enable 0x0010 Discipline enable 0x0020 Ultra
67. vice Except for products returned to Customer from another country Jackson Labs Technologies Inc shall pay for return of products to Customer If Jackson Labs Technologies Inc is unable within a reasonable time to repair or replace any product to condition as warranted the Customer shall be entitled to a refund of the purchase price upon return of the product to Jackson Labs Technologies Inc 6 1 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 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 O 2014 Jackson Labs Technologies Inc 67 CSAC GPSDO User Manual Jackson Labs 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 6 1 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 DIRE
68. with the last internal offset stored in NVRAM effectively storing the calibration parameter inside the CSAC oscillator once per day Figure 2 7 CSAC steering display page e CSAC Status Figure 2 8 This page displays the following Cesium Vapor Cell status Laser Current LI Cell Temperature in C and TCXO Steering Voltage OV to 3 3V The TCXO is locked to the Cesium Vapor Cell via a Phase Locked Loop and generates the 1OMHz output frequency O 2014 Jackson Labs Technologies Inc 13 CSAC GPSDO User Manual J a C k S onj Labs Figure 2 8 CSAC status display page TINT Figure 2 9 TINT is the time interval offset between the internal CSAC oscillator phase and UTC as generated by the GPS receiver It is displayed in nanoseconds The PLL control loop will try to zero this offset over time as the unit follows UTC at NIST in Colorado via the Satellite transmissions FEE indicates the Frequency Error Estimate which is a unit less number and is estimated by comparing the UTC phase offset from 1000 seconds ago to the present phase offset This is similar to the Allan Deviation number for a measurement interval of 1000 seconds Smaller numbers are better but numbers below 1E 012 are below the noise floor of the instrument A number of 4E 012 for example can be loosely interpreted to be a phase drift of the 10MHz and 1PPS outputs of 4 picoseconds per second averaged over 1000 seconds as compared to the UTC master clock at NIST in C
69. 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 5 5 Graph display GPSCon Utility Pro GPSCon COM8 x Ss E ackson Labs FireFlyl Firmware Rev 2 19 Life 440 EFC 2 414181 ad 0m sd 0 04m J TI max ns 20 emp Fiter coeff 0 025 MEA Jr Stop Span mins 15000 o Hide Not Tracking 0 PRN El z TI av 0 03n sd 11n 2 41396 0 13560 93 0 ns ed hia aii A lk i LON W 11 57 40 127 VTC 2 36 25 16 Now 010 LaT N 27 15 39 756 6 50 m MSL 77 0 ns 0 start 14 45 02 07 11 10 UTC 203 86 hrs Send serztar 18 02 47 15 1110 UTC Receiver timeout 7 servitar T Log Status M Log sat count Translate time codes 2584 95 6348 7 66236 0 0054106 4 072305 0 00530379 M LogEFC 2414181 Options F TltoGPS fT1E 08 0157483 FT Log PU fi Pic E EE Continuously read error queue Flash LED Last error t sys time 64 2014 Jackson Labs Technologies Inc Jackson 7 Figure 5 6 Expanded Graph Display GPSCon Utility Pro GPSCon COM8 Status Time Map J Graph Export Help About CSAC GPSDO User Manual E ackson Labs FireFly ll Firmware Rev 2 19 o Lite fed 02 38 51 16 1410 EFC 2 414208 ad 0m sd 0 05m D TI max n
70. y other serial control O 2014 Jackson Labs Technologies Inc 5 CSAC GPSDO User Manual Jackson Labs software to send commands and query status from the unit The third party application GPSCon is recommended for monitoring and controlling the unit This software is available at http www realhamradio com gpscon info htm JLT also provides a freeware control program called Z38xx and this application program can be downloaded from the following website www jackson labs com index php support The RS 232 serial port on connector J1 operates in parallel to the USB serial port and commands can be sent and queried independently to and from both connectors English language SCPI GPIB commands are available to switch the default serial output of the unit from the RS 232 serial port to the USB port and vice versa 2 3 Operating the unit from the RS 232 port 1 Connect a 5V compatible GPS antenna to connector J4 2 Plug in aclean DC power source of between 8V to 32V 36V max to the power pins 15 and 16 of connector J1 Plug in the Ground connection to pins 12 and 14 of connector J1 RS 232 Serial TX and RX signals are available on pins 9 and 8 respectively of connector J1 Make sure not to accidentally short out adjacent pins 13 and 15 of connector J1 as this would severely damage the board WARNING PLEASE MAKE SURE NOT TO CONFUSE POWER CONNECTOR J1 AND LCD CONNECTOR J3 AS THESE TWO CONNECTORS ARE MECHANICALLY IDENTICAL AND ARE THUS EASY

CSAC GPSDO User Manual - Jackson Labs Technologies, Inc.

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