Home

Mini-JLT™ User Manual - Jackson Labs Technologies, Inc.

Contents

1. 13 3 35 GPSIGPGGA pa a amp d a amp 44 008 3 3 6 GPS GGASTat 14 3 3 7 GPS GPRMC 14 3 3 8 GPS GPGSV 14 3 3 9 GPS XYZSPeed IA 3 3 10GPS GPZDA 0 ID 3 3 11GPS PASHR s a aso s soa a oio a a om doa doa ID 3 3 12GPS GYRO 16 3 3 13GPS GYRO CAL s a s as a 18 3 3 14GPS DYNAMic MODE aa a a BA 3 3 15GPS DYNAMic MODE 8 Automatic Dynamic Mode LE On a De O 3 3 16GPS DYNAMic STATe 000 0 20 3 3 17GPS REFerence ADELay lt float gt lt s ns gt j 32767ns s 32767ns1 ca 2 gt 220 3 3 18GPS REFerence PULse SAWtooth amp 1 3 3 19GPS RESET ONCE june og SM mle gt si 3 3 20GPS TMODe lt ONJOFFIRSTSURV bata Grae ae ee etd ar CE 3 3 21GPS SURVey ONCE fe SO as Se Ge ge oe 5 a a 3 3 22GPS SURVey DURation lt sec gt 21 3 3 23GPS SURVey VARIANCE lt mm 2 gt HI 3 3 24GPS HOLD POSition lt cm cm cm gt 22 2012 Jackson Labs Technologies Inc 1 Mini JLTTM User Manual J a ck 5 on Labs 3 3 25GPS SURVEY STATus DURation 22 3 3
2. Ref Name Function Specification Description J1 Pin 1 1PPS In Optional external 1PPS OV to 5V pulled low by 4 7K Alternate 1PPS reference input Input resistor J1 Pin 2 Serial TX Serial Transmit Output 3 3V LVCMOS RS 232 serial Serial Transmit output for NMEA and optional SCPI sentences internally connected to USB TX signal J1 Pin 3 Serial RX Serial Receive Input 3 3 LVCMOS RS 232 serial Serial Receive input for SCPI optional 5V compatible commands internally wired ored to USB RX signal J1 Pin 4 Ground Ground Ground Main Power Return J1 Pin 5 VANT External Antenna 3 0V to 5 5V up to 100mA The unit provides a 3 3V antenna Voltage supply to the GPS antenna by default This can be over driven by a voltage gt 3 3V supplied to the VANT pin Both the internal 3 3V and the external VANT supply are diode ored and protected against each other The VANT current is fused by a 100mA self resetting fuse on the PCB J1 Pin 6 5V Power Main Power Supply 4 0V to 6 0V range 5V nominal Supplies power to the unit and the OCXO Up to 8W are required during warmup Range is 5V 1 0V 2012 Jackson Labs Technologies Inc Mini JLT User Manual Jac son 0 J5 Pin 3 LOCK OK Lock and Event 3 3V LVCMOS 3 3V Unit Locked to GPS and no indicator events pending OV Event is pending events can be queried via the sync health command Not stuffed by
3. 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 5 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 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 O 2012 Jackson Labs Technologies Inc 19 Mini JLTTM User Manual Ja ck 5 on Labs 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 wil
4. Mini JLTTM User Manual Ja ck 5 on Labs 3 10 3 SERVo COARSeDac This command sets the coarse DAC that controls the EFC The Mini JLT control loop automatically adjusts this setting The user should not have to change this value This command has the following format SERVo COARSeDac lt int gt 0 225 3 10 4 SERVo DACGain This command is used for factory setup 3 10 5 SERVo EFCScale Controls the Proportional part of the PID loop Typical values are 0 7 double oven OCXO to 6 0 simple single oven OCXO Larger values increase the loop control at the expense of increased noise while locked Setting this value too high can cause loop instabilities This command has the following format SERVo EFCScale lt float gt 0 0 500 0 3 10 6 SERVo EFCDamping Set s the Low Pass filter effectiveness of the DAC Values from 2 0 to 50 are typically used Larger values result in less noise at the expense of phase delay This command has the following format SERVo EFCDamping lt float gt 0 0 4000 0 3 10 7 SERVo SLOPe The parameter determines the sign of the slope between the EFC and the frequency variation of the OCXO This parameter should be set to match your OCXO s EFC frequency slope This command has the following format SERVo SLOPe lt NEG POS gt 3 10 8 SERVo TEMPCOmpensation This command is not supported on the Mini JLT board 3 10 9 SERVo AGINGcompensation This parameter is a coefficient that repr
5. J a ck 5 on Mini JLTTM User Manual Labs GPSCon Utility 5 1 Description GPSCon is a program for the monitoring and control of a variety of GPS time and frequency standard receivers It communicates with the receiver using the SCPI command set This utility can be obtained directly from Real Ham Radio com at the following URL http www realhamradio com gpscon buy now htm Important note On newer faster computers running Windows 7 GPSCon may not acquire data correctly If you encounter this problem it is recommended that you install GPSCon on a slower computer using Windows XP 5 2 Installation Follow the directions that come with GPSCon for installing the utility on your computer 5 3 Using GPSCon The GPSCon utility has a help file that should be consulted in order to get the full functionality of this utility Only a few of the features and commands are mentioned in this appendix for convenience 5 3 1 Setting the options To set up the options for your GPSCon session press the Options button below the display area The window shown in Figure 5 1 will appear You can select from the tabs which options you wish to set 2012 Jackson Labs Technologies Inc 43 Mini JLT User Manual Figure 5 1 Options window Jackson 0 2 GPSCon Utility Pro GPSCon COMA gt E r Logging and graph Time J e p Graph Export Help About Max kB 0 unlim
6. Mini JLTTM User Manual Ja ck 5 on Labs Carrier Phase tracking 1s 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 Sea Used on Ships where altitude is expected to be constant Airborne lg Airborne applications with less than 1g acceleration Airborne lt 2g Airborne applications with less than 2g acceleration Airborne lt 4g Airborne applications with less than 4g acceleration Automatic Mode Select one of the above states 0 7 based on the actual velocity of the vehicle 18 The Mini JLT 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 20 for a description of the GPS
7. no flow control 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 Mini JLT 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 3 2 General SCPI Commands 3 2 1 Quick Start Commands For a quick start try the following SCPI serial port commands help syst stat gps sync meas 3 2 2 IDN This query outputs an identifying string The response will show the following information O 2012 Jackson Labs Technologies Inc 11 Mini JLTTM User Manual Ja ck 5 on Labs lt company name gt lt model number gt lt serial number gt lt firmware revision gt 3 2 3 HELP This query returns a list of the commands available for the Mini JLT GPSDO 3 3 GPS Subsystem 12 N B Firmware revision 2 37 and above adds support for the standard NMEA GPGS V string as well as the GPS FWver command that allows query of the firmware revision used inside the GPS receiver itself Note Please note that Mini JLT M displays antenna height in MSL Meters r
8. 0 simple single oven OCXO are typical 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 Mini JLT 1PPS signal and the UTC 1PPS signal as generated by the GPS receiver Set higher values for tighter phase following at the expense of frequency stability Typical values range from 4 30 25 being the default Setting this value too high may cause loop instability A well compensated unit will show performance similar to the plot shown in Figure 2 3 when experiencing small perturbations 8 2012 Jackson Labs Technologies Inc J a C ks on abs Mini JLT User Manual Figure 2 3 Mini JLT phase compensation plot EFC 2 409962 ad 0m sd 0 07 m 3 Current 2 4098 7 28 0 ns Tl av 1 03n sd 4 7 n F Client mode T 2012 Jackson Labs Technologies Inc 9 Mini JLTTM User Manual J a ck 5 on Labs 10 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM User Manual Labs SCPI Control Quick Start Instructions 3 1 Introduction The SCPI Standard Commands for Programmable Instrumentation subsystem is accessed via the TTL or USB serial interfaces and a terminal program By default the terminal settings are 115200 8N 1
9. 26GPS SURVEY STATUS 22 3 3 27GPS INITial DATE lt yyyy mm dd gt 22 3 3 28GPS INITial TIME lt hour min sec gt 22 3 3 29GPS JAMlevel ee 22 3 3 30GPS FWver 2 3 3 31GPS 2 A ES de i at A a e 8 3 4 GYRO SUBSYSTEM er aea O 3 4 1 GYRO MODE lt ON OFF gt Eo a dee ee we O 3 4 2 GYRO TRACE lt int gt 0 255 DEENEN 3 4 3 GYRO CAL lt float float float float float float gt Ke ab 4 8 3 4 4 GYRO CAL COMPUTE a Ae a eet il ey eat as O 3 4 5 GYRO SENS GYRO EFC and GPS CAL RESET tech 8 gt 224 3 4 6 GYRO GLOAD 00000 2A 3 5 PTIME Subsystem s s ans ca S 3 5 1 PTIMe DATE 24 3 5 2 PTIMe TIME 24 3 5 3 PTIMe TIME STRing 24 3 5 4 PTIMe TINTerval 24 3 5 5 PTIMe LEAPsecond a 25 3 5 6 PTIME CD 3 6 SYNChronization Subsystem x 3 2 Seb a bw 4 25 3 6 1 SYNChronization HOLDover DURation a ZO 3 6 2 SYNChronization HOLDover INITiate ada ue ce O 3 6 3 SYNChronization HOLD
10. 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 factory default setting 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 21 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 22 GPS SURVey DURation lt sec gt This command sets the Survey minimal duration 3 3 23 GPS SURVey VARIANCE lt mm22 gt This command specifies the minimum variance of the average position computed during the Survey This 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 18 under the specified minimum variance O 2012 Jackson Labs Technologies Inc 21 Mini JLTTM User Manual Ja ck 5 on Labs 3 3 24 GPS HOLD POSition lt cm cm cm gt This command allows the user to specify manually the exact position of the unit 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 25 GPS SURVEY STATus DURation This query specifies the duration of the survey in progress or
11. Once the green LED D1 is on the unit will output 10MHZ with significantly better than 1ppb frequency accuracy By default the unit will be set to Position Hold mode and an antenna position Auto Survey process is started after power on that may take up to 3 hours to finish The antenna should never be moved when the unit is set to run in Position Hold mode as this would result in loss of frequency and timing accuracy and incorrect GPS fixes The unit must be configured to mobile mode using the GPS TMODE OFF command when used in an application where the antenna position can move during normal operation Using the Auto Survey process and Position Hold mode allows the unit to over determine the timing solution and also allows TRAIM operation which will result in slightly higher timing stability and more robust GPS reception in challenged environmental conditions such as under foliage in urban canyons etc 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 5V power Connect a terminal program TeraTerm is recommended to the unit via the TTL serial connector pins on 11 or to the USB serial port both with 115 2KB 8N1 and no flow control O 2012 Jackson Labs Technologies Inc 3 Mini JLTTM User Manual J a ck 5 on Labs WARNING Do not connect RS 232 serial levels to connector J1 the unit may get damaged fro
12. 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 O 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs 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 previous products such as the FireFly IIA GPSDO units which did not support Position Hold Auto Survey modes 3 3 15 GPS DYNAMic MODE 8 Automatic Dynamic Mode Automatic Dynamic Mode allows the Mini JLTTM 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 setting for any given velocity The unit is able to set 7 different modes as shown in section 3 3 14 The following table shows the Dynamic mode the unit will program into the GPS receiver when Automatic Mode is selected Dynamic Mode 8
13. default for legacy compatibility J5 Pin 2 ISP and GPS Enable ISP mode 3 3V LVCMOS open collector Enables In System Programming Detect indicate GPS signal pulled to 3 3V via 4 7K resistor mode ISP when pulled low during detection Do not load this pin to power on typically enabled by using ground as this would enable a jumper to pin 1 ISP mode during power on Use an LVCMOS input to 3 3V GPS is receiving a sat fix query the state of this pin OV GPS is not receiving a sat fix Not stuffed by default for legacy compatibility J5 Pin 1 Ground Ground Ground Ground Not stuffed by default for legacy compatibility J4 GPS Antenna Antenna Input 11 3 3V default to 5 5V Supplies 3 3V by default and up to 5 5V when using external antenna power feed on J1 Fused with 100mA self resetting fuse J6 10MHz output 10MHz Sine Wave 13dBm 3dBm 10MHz output from isolated Output distribution amplifier driven by on board OCXO Not stuffed by default for legacy compatibility J2 10MHz output 10MHz Sine Wave 5dBm 3dBm 10MHz output output from isolated Output distribution amplifier driven by on board OCXO U17 USB USB command and USB 2 0 USB interface for SCPI and NMEA control sentences Runs in paralell to TTL serial port Auto switchover between TTL and USB ports J3 1PPS output 1PPS output signal 3 3V LVCMOS lt 5ns rise time 1PPS output signal rising edge aligned to UTC 10 Ohms output impedance aligned to UTC when locked t
14. from the X Axis and keep the Y and Z axis without offset or gain adjustments After the Offset is removed we may have to adjust the gain of the axis sensor For example if the range of the X Axis output is 82 Degrees to 78 Degrees then the axis has both an offset of 2 degrees and a gain error of 90 80 Degrees a factor of 1 125 Thus we need to add 2 Degrees offset and a gain of 1 125 The calibration command would thus look as follows GPS GYRO CAL 2 0 0 1 125 1 1 All three axis need to be calibrated simultaneously as shown above for the X Axis GPS GYRO CAL returns the setting of the calibration factors of the accelerometer system Due to the nature of the accelerometer chip the Z axis will have the largest error and lowest sensitivity of all three axis The X and Y axis will have the best resolution and highest sensitivity when the unit is sitting level horizontally 3 3 14 GPS DYNAMic MODE This command allows the user to select the dynamic motion model being applied to the Kalmann 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 2012 Jackson Labs Technologies Inc 17
15. lt ON OFF gt O 2012 Jackson Labs Technologies Inc 29 Mini JLTTM User Manual Ja ck 5 on Labs 3 9 1 2 SYSTem COMMunicate SERial PROmpt This command enables disables the prompt scpi gt on the SCPI command lines The prompt must be enabled when used with the software GPSCon This command has the following format SYSTem COMMunicate SERial PROmpt lt ON OFF gt 3 9 1 3 SYSTem COMMunicate SERial BAUD This command sets the TTL serial speed The serial configuration is always 8 bit 1 stop bit no parity no HW flow control Upon Factory reset the speed is set at 115200 bauds This command has the following format SYSTem COMMunicate SERial BAUD lt 9600 19200 38400 157600 115200 gt 3 9 2 SYSTem STATus This query returns a full page of GPS status in ASCII format The output is compatible with GPSCon 3 9 3 SYSTem FACToryReset ONCE This command applies the Factory Reset setting to the EEPROM All aging tempco and user parameters are overwritten with factory default values 3 10 SERVO Subsystem This subsystem regroups all the commands related to the adjustment of the servo loop SERVo COARSeDac lt int gt 0 225 SERVo DACGain lt int gt 0 1 10000 SERVo EFCScale lt float gt 0 0 500 0 SERVo EFCDamping lt float gt 0 0 4000 0 SERVo SLOPe lt NEG POS gt SERVo TEMPCOmpensation lt float gt 4000 0 4000 0 SERVo AGINGcompensation lt float gt 10 0 10 0 SERVo PHASECOrrection lt floa
16. to the GPS GYRO command Please see the GPS GYRO command for details 3 4 3 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 optional Accelerometer output Please see the GPS GYRO CAL command for details See also the GYRO CAL COMPUTE command for a semi automated calibration method 3 4 4 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 the earth s gravity 2012 Jackson Labs Technologies Inc 23 Mini JLTTM User Manual J a ck 5 on Labs 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 5 GYRO SENS G
17. 04 LPC2105 LPC2106 LPC2109 oo LPC2114 LPC2119 oo LPC2124 SY LPC2129 LPC2131 LPC2132 LPC2134 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 38400 or slower Faster Baud rates will not work properly 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 Mini JLT 4 5 Verifying Firmware Update Power cycle the unit with the pin 2 of JS ISP left floating 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 2012 Jackson Labs Technologies Inc 41 Mini JLTTM User Manual 0 a C k 5 on Labs 42 2012 Jackson Labs Technologies Inc
18. 5 0V nominal voltage The current is typically less than 0 6A at 5V Connect a clean 5V power supply to pin 6 of J1 and ground to pin 4 of J1 Both USB power and external 5V power can be connected at the same time to the unit but USB power will not be used to drive circuits on the PCB 2 3 Connecting the GPS Antenna Connect the GPS antenna to the SMA connector J4 Caution use a Lightning Arrestor on your Antenna setup Use an amplified GPS antenna that is 5V LNA compatible The Mini JLT GPS receiver is a 50 channel high sensitivity GPS receiver with very fast lock time The Mini JLT unit is set at the factory to use Position Hold mode and will initiate an Auto Survey process after power on to establish its new position The Auto Survey process may last up to 3 hours The units antenna should not be moved when set to Position Hold mode Please set the unit to mobile mode using the GPS TMODE OFF command when the unit is to be used in a mobile environment where the antenna position can change more than 1 foot during operation The Mini JLT is capable of generating standard navigation messages see GPS GPGGA GPS GPZDA GPS PASHR and GPS GPRMC TTL serial commands that are compatible with most GPS based navigation software The GPS receiver generates a 1PPS time signal that is phase synchronized to UTC This 1PPS signal is used to frequency lock the 10MHZ output of the Mini JLT GPSDO to UTC thus disciplining the unit s 10MHz f
19. 6 LON 9 17 6 50 m MSL Sat count lu 77 0 ns start 14 45 02 07 11 10 UTC 203 86 hrs Send senztar e 18 02 47 15 11 10 UTC Receiver timeout tar T Log Status N Log sat count Translate time codes 2594 95 6348 7 66236 0 0054106 4 072305 0 00530379 M Log EFC 2 414181 Options GE Iw Tlto GPS 8 0 157483 FT Log PU fi Client mode A Lans Update now I Continuously read error queue Flash LED Last error Get sy me 0 2012 Jackson Labs Technologies Inc Jackson Ke Figure 5 6 Expanded Graph Display 57 GPSCon Utility Pro GPSCon COM8 Status Time Map J Graph Export Help About Mini JLT User Manual iJ ackson Labs FireFly ll Firmware Rev 2 19 0 Life fed 02 38 51 16 1410 EFC 2 414208 ad 0m sd 0 05m D TI max ns 20 H 2 4r A 159494 Temp Filter coeff 0 025 Stat Span mins 15000 se Hide Not Tracking l PRN El z 15 1 40 d lj AN i VTC 1 35 45 16 Now 2010 LaT N 27 15 29 756 LON W 121 57 40 195 7 20 m MSL 0 Sat count 69 0 ns start 17 27 41 15 11 10 UTC Send serv tar D 18 02 47 15 11 10 UTC Receiver timeout z serv tar J Log Status V Log sat count Translate time codes 2584 95 6348 7 66236 0 0054106 4 072305 0 00530379 Log EFC 2414209 Options scpi gt Tlto GPS F11E 09 0 158524 I Log PU fl in zit Update now D Continuously read error queue Flash LED Last error r 5 3 4 Expor
20. GGA This command instructs the Mini JLT to send the NMEA standard string GPGGA every N seconds with N in the interval 0 255 The command is disabled until the GPS receiver achieves a first fix This command has the following format O 2012 Jackson Labs Technologies Inc 13 Mini JLTTM User Manual Ja ck 5 on 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 6 GPS GGASTat This command instructs the Mini JLT 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 until the GPS receiver achieves a first fix This command has the following format GPS GGASTat lt int gt 0 255 This command replaces the regular NMEA GGA validity flag with a decimal number indicating the lock state of the unit Please see section SERVo TRACe for a detailed description of the lock state variable The command allows capture of the position and other information available in the GGA command as well as tracking the lock state and health of the unit s OCXO performance GGASTat shows height in MSL Meters this is different from traditional GPS receivers that display height in GPS Meters The difference between MSL and GPS height can be significant 35m or more are common 3 3 7 G
21. Jackson N Mini JLT User Manual ocument 80200515 Mini JLT User Manual Copyright O 2010 2011 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLT User Manual Labs 1 Introduction 1 1 Overview e 1 2 General Safety Precautions ET 2 1 2 1 Antenna Lightning Protector 2 1 2 2 Grounding Po 2 1 2 3 Power Connections 2 1 2 4 Environmental Conditions 2 2 Quick Start Instructions 2 1 Powering Up the Unit 3 2 1 1 PCB Photos 4 2 1 2 Mechanical Drawings 2 2 1 3 Notes on Signal Interfacing 6 2 1 4 Coaxial Connectors 7 2 2 Power 7 2 3 Connecting the GPS Antenna y Y 2 4 Remote serial control 7 2 5 Loop parameter adjustment 8 3 SCPI Control Quick Start Instructions 11 3 1 Introduction E all 3 2 General SCPI Commands D F Re 0 ee 7 3 2 1 Quick Start Commands 11 322 DNZ pe au aia A ll 3 2 3 A ea 8 4 ee 2 da ed 3 3 GPS Subsystem s a aao a m sosa soa 12 3 3 1 GPS SATellite ek gt Je oy ey Sd e tr dS 3 3 2 GPS SATellite TRAcking COUNt ore Be ae e ae 218 3 3 3 GPS SATellite VISible COUNt 18 3 3 4 NMEA Support
22. LPC2000 Flash Utility File Buffer Help LPC2000 Flash Utility V2 2 3 Flash Programming 4 Erase Blank gt Communication Filename Connected To Port SARMiFury_GPSDO ApplicationimainFur Blank Check e Entire Device COM1 C Selected Sectors CSC pu 5 Upload to Flash GH Ste SE E Start Sector 3 Ft rase Sp Compare Flash Manual Rese EndSection ep Time Out sec Pa Device Use DTR ATS Device LPC2106 get Part for Reset and Boot Loader XTAL Freq kHz 10000 Device ID Boot Loader ID Selection EU Fi LPC2000 Flash Utility Reset Message Please reset your LPC2000 board now and then press OK OK Press the OK button and the download should start Sometimes the utility gets confused and this process from item 4 4 B has to be tried several times It is not necessary to press reset as the utility is asking Just press OK on the utility window s button Warning DO NOT PRESS THE ERASE BUTTON AT ANY TIME THIS WILL RENDER THE PCB USELESS AND CAN ONLY BE RECOVERED AT THE FACTORY 4 4 2 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 38 O 2012 Jackson Labs Technologies Inc Jacks on Mini JLT User Manual Labs Figure 4 3 Flash Magic utility lana 3 lt 0 3 Step 1 Co
23. PS GPRMC This command instructs the Mini JLT to send the NMEA standard string GPRMC every N seconds with N in the interval 0 255 The command is disabled until the GPS receiver achieves a first fix This command has the following format GPS GPRMC lt int gt 0 255 3 3 8 GPS GPGSV This command instructs the Mini JLT to send the NMEA standard string GPGS V 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 3 3 9 GPS XYZSPeed 14 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 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs 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 Leapsecond 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 10 GPS GPZDA This c
24. YRO EFC and GPS CAL RESET Used for factory calibration of Gyro subsystem 3 4 6 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 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 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 24 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs 3 5 5 PTIMe LEAPsecond This command returns the leapseconds accrued between the GPS and UTC time systems 3 5 6 PTIME This query returns at once the result of the four following queries PTIME DATE PTIME TIME PTIME TZONE PTIME TINTerval PTIMe LEAPsecond 3 6 SYNChronization Subsystem This subsystem regroups the commands related to the synchronization of the Mini JLT with the GPS receiver The list of the commands sup
25. ather than in GPS Meters on all commands that return antenna height the legacy Fury GPSDO uses GPS height The NMEA position fixes are in the WGS84 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 SATellite VISible COUNt GPS GPGGA lt int gt 0 255 GPS GGASTat lt int gt 0 255 GPS GPRMC lt int gt 0 255 GPS GPGSV lt int gt 0 255 GPS GPZDA lt int gt 0 255 GPS PASHR lt int gt 0 255 GPS XYZSPeed GPS GYRO GPS GYRO CAL GPS DYNAM ic lt int gt 0 7 GPS DYNAMic 8 Automatic Dynamic Mode GPS DYNAMic GPS REFerence ADELay lt float gt lt s ns gt 32767ns 32767ns GPS REFerence PULse SAWtooth GPS RESET ONCE GPS TMODE lt ONIOFFIRSTSURV 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 DURation 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs GPS SURVEY STATUS GPS INITial DATE lt yyyy mm dd gt GPS INITial TIME lt hour min sec gt GPS JAMlevel GPS FW ver GPS 3 3 1 GPS SATellite This group of commands describe the satellite constellation 3 3 2 GPS SATellite TRAcking COUNt This query returns the number of satellites being track
26. cates a strong jamming signal of gt 50 HEALTH STATUS l 0x800 range is 0 to 255 As an example if the unit is in GPS holdover and the OCXO voltage is too high and the UTC phase offset is gt 250ns then the following errors would be indicated 1 UTC phase gt 250ns 0x4 2 OCXO voltage too high 0x40 2012 Jackson Labs Technologies Inc 27 Mini JLTTM User Manual Ja ck 5 on Labs 3 GPS in holdover 0x10 Oring these values together results in 0x40 0x10 0x4 0x54 The unit would thus indicate HEALTH STATUS 0x54 A health status of 0x0 indicates a properly locked and warmed up unit that is completely healthy 3 6 12 SYNChronization This query returns the results of these four queries SYNChronization SOURce MODE SYNChronization SOURce STATE SYNChronization LOCKed SYNChronization HOLDover DURation SYNChronization health 3 7 DIAGnostic Subsystem This subsystem regroups the queries related to the diagnostic of the TCXO 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 It returns a percentage value between 100 to 100 3 7 2 DIAGnostic ROSCillator EFControl ABSolute This query returns the El
27. d ground source such as power supply ground This should be done before handling the circuit board or anything connected to it 1 6 the GPS antenna 1 2 3 Power Connections Make sure to connect the DC power to the device following the polarity indicated in Section 2 1 Do not reverse the power pins as this will cause serious damage to the circuit board 1 2 4 Environmental Conditions This instrument is intended for indoor use It is designed to operate at a maximum relative non condensing humidity of 95 and at altitudes of up to 50 000 meters Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range 2 O 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM User Manual Labs Quick Start Instructions 2 1 Powering Up the Unit To operate the unit simply follow these two steps 1 Connect a 3 3V or 5V compatible GPS antenna to SMA connector J4 The antenna can be passive or active The Mini JLTTM board will supply 3 3V to the antenna by default and this can be increased to up to 5 5V through the external antenna power supply pin 5 of connector J1 2 Connect 5V 1V DC Power to J1 pin 6 on the unit and ground to pin 4 of J1 The unit will consume up to 8W of power during oscillator warmup The unit will now lock to GPS Red LED D1 is blinking when satellites are being received and will indicate proper lock and no events pending when the Green LED D1 goes on
28. e of an auxiliary measurement You will notice that the Aux 1 request string has been set to meas current lt CD gt and the Log Aux box is checked In the area below labeled Traces to be visible on the graph the box Aux 1 is checked and the label OCXO curr has been added 44 O 2012 Jackson Labs Technologies Inc Jacks ony aba Mini JLT User Manual Figure 5 2 Setting the communications parameters GPSCon Utility Pro GPSCon COM4 r Status Time Map I Graph Export Help SN PRN EL AZ SS VdmLabs Firmware Rev 2 19 C RTS CTS 2012 Jackson Labs Technologies Inc 45 Mini JLTTM User Manual J a ck 5 on Labs Figure 5 3 Auxiliary Parameters window 3 A E Paths amp settings FTP Email Coms Time services Anden Aux coms Export graphics Remote control o cna Y 2nd port eror request string SYST ERR lt CR gt Enable second serial port 2nd port OK prompt scpi lt SPC gt gt lt SPC gt Wildcard for any character type is 7 Wildcard for numeric character is Y Camiage retum is 2nd port error prompt E7 H gt lt SPC gt lt CR gt Linefeed is LES Aux request string meas curent lt CR gt M Log An or Log Max SS Aux2 request string DT T Log Aux2 or Log MinSS Aux3 request string DATA E47 lt CR gt T Log Asch Traces to be visible on the graph KE EFC Mag Hold Min Max filter Ait coeff Label Offset en M A O0 cur fi
29. ectronic Frequency Control EFC output value of the internal reference oscillator It returns a value in volts between 0 and 5 V 3 7 3 DIAGnostic LlFetime COUNt This command returns the number of hours the unit has been powered on 28 O 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM User Manual Labs 3 8 MEASURE Subsystem This subsystem regroups the queries related of some parameters that are measured on board on the Mini JLT The list of the commands supported for this subsystem is the following MEASure VOL Tage MEASure CURRent MEASure 3 8 1 MEASure VOLTage This query returns the power supply voltage applied to the OCXO 10 45V 3 8 2 MEASure CURRent This command is not supported on the Mini JLT board 3 8 3 MEASure This query returns the result of the two following queries MEASure VOLTage MEASure CURRent 3 9 SYSTEM Subsystem This subsystem regroups the commands related to the general configuration of the Mini JLT The list of the commands supported for this subsystem follows SYSTem COMMunicate SERial ECHO lt ON OFF gt SYSTem COMMunicate SERial PROmpt lt ON OFF gt SYSTem COMMunicate SERial BAUD lt 9600 19200 38400 57600 115200 gt SYSTem STATus SYSTem FACToryReset ONCE 3 9 1 SYSTem COMMunicate 3 9 1 1 SYSTem COMMunicate SERial ECHO This command enables disables echo on TTL serial This command has the following format SYSTem COMMunicate SERial ECHO
30. ed 3 3 3 GPS SATellite ViSible COUNt This query returns the number of satellites PRN that the almanac predicts should be visible given date time and position 3 3 4 NMEA Support The following four commands allow the Mini JLT M GPSDO to be used as an industry standard navigation GPS receiver The GPGGA GPRMC GPGSV 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 Mini JLT serial interfaces Once enabled Mini JLT will send out information on the TTL and USB serial transmit pin automatically every N seconds All incoming serial commands are still recognized by Mini JLTTM since the serial 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 Mini JLT 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 5 GPS GP
31. een the 1PPS output and the UTC 1PPS signal can be queried with the command SYNC TINT and this offset should be taken into account 20 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM User Manual Labs when calibrating two unit s 1PPS outputs to each other since the lock algorithms will try to steer the OCXO for a 0 0ns offset to the UTC 1PPS time pulse 3 3 18 GPS REFerence PULse SAWtooth This command returns the momentary sawtooth correction factor that the GPS receiver indicated 3 3 19 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 to commence after a GPS reset as indicated by the red blinking LED 3 3 20 GPS TMODe lt ON OFF RSTSURV gt This command selects the Timing Mode of the GPS 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
32. erence clock over long periods of time The unit disciplines its internal 1OMHz reference to within less than 80ns peak to peak of UTC at all times which is less than one complete clock cycle at 10MHz 50 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM 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 service 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 I
33. esents the drift of the EFC needed to compensate the natural drift in frequency of the OCXO due to aging This coefficient is automatically computed and adjusted over time by the Jackson Labs Technologies Inc firmware This command has the following format SERVo AGINGcompensation lt float gt 10 0 10 0 32 O 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs 3 10 10 SERVo PHASECOrrection This parameter sets the Integral part of the PID loop Loop instability will result if the parameter is set too high Typical values are 10 0 to 30 0 This command has the following format SERVo PHASECOrrection lt float gt 100 0 100 0 3 10 11 SERVo 1PPSoffset This command sets the Mini JLTTM 1PPS signal s offset to UTC in 16 7ns steps Using the SERV 1PPS command results in immediate phase change of the 1PPS output signal This command has the following format SERVo 1PPSoffset lt int gt ns 3 10 12 SERVo TRACe This command sets the period in seconds for the debug trace Debug trace data can be used with Ulrich Bangert s Plotter utility to show UTC tracking versus time etc This command has the following format SERVo TRACe lt int gt 0 255 An example output is described here 08 07 31 373815 60685 32 08 2 22E 11 14 10 6 0x54 date 1PPS Count Fine DAC UTC offset ns Frequency Error Estimate Sats Visible Sats Tracked Lock State Health Status Please see the SYNChronization co
34. fo r fo bes 5 e pu Tas be o r fo 3 rb F Sas D Au 1 fo Ch 103 0 05 5 3 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 5 3 2 Sending manual commands to the receiver You can send SCPI commands manually by using the drop down box under the display window as shown in Figure 5 4 Care must be taken when sending these commands so be sure that the command that you select is supported by the Mini JLT GPSDO Once you ve selected the command you can press Send to send it to the Mini JLT 46 O 2012 Jackson Labs Technologies Inc Jackson Ke Figure 5 4 Sending manual commands Status Time Map Graph Export Help About VdmLabs Firmware Rev 2 19 Life Not Tracking 3 Stat Jr PRN El Az 15 2 147 Stop 18 7 261 26 4 118 Hide UTC 22 56 52 28 Oct 2010 LAT N 37 16 52 397 LON Y 121 59 15 645 74 16 m HSL Current OK 0 06 GPS Receiver Status 3D Fix 1PPS SOURCE MODE GPS GPSDO Status Locked DIAG LOG READ ALL DIAG LOG READ DIAG ROSC EFC ABS DIAG ROSC EFC REL M Tlto DIAG TEMP F L DIAG TEST RES 99 DIAG TEST ALL T Conti SPS INIT DATE ar mo dau GPS INIT POS IN deg mp ze Ai dea mm sec elev Last error E 2 7 22 33 33 28 10 10 UTC Receiver timeout 7 22 39 48 28 10 10 UTC Receiver timeout 22 39 58 28 10 10 UTC Receiver timeo
35. ial BAUD 29 3 9 2 SYSTem STATus os eh fs as a a 3 9 3 SYSTem A ONCE pa a a a O 3 10SERVO Subsystem 3 10 1SERVo FASTlock 80 3 10 2SERVo FALEngth A 2 2012 Jackson Labs Technologies Inc Jac son Ke 3 10 3SERVo COARSeDac 3 10 4SERVo DACGain 3 10 5SERVo EFCScale 3 10 6SERVo EFCDamping 3 10 7SERVo SLOPe 3 10 8SERVo TEMPCOmpensation 3 10 9SERVo AGINGcompensation 3 10 10SERVo PHASECOrrection 3 10 11SERVo 1PPSoffset 3 10 12SERVo TRACe 3 10 13SERVo 4 Firmware Upgrade Instructions 4 1 Introduction 4 2 ISP Flash Loader Utility installation 4 2 1 Philips LPC2000 Flash Utility 4 2 2 Flash Magic Flash Programming Utility 4 3 Putting the PCB into In Circuit ae cae mode 4 4 Downloading the firmware 4 4 1 Philips LPC2000 Flash Utility 4 4 2 Flash Magic Flash bel um 4 5 Verifying Firmware Update 5 GPSCon Utility 5 1 Description 5 2 Installation 5 3 Using GPSCon 5 3 1 Setting the options 5 3 1 1 Communication Parameters 5 3 1 2 Auxiliary parameters 5 3 1 3 Other options 5 3 2 Sending manual commands to the 1 receiver 5 3 3 Use of the mouse in graph mode 5 3 4 Exporting the graphics 5 4 Interpreting the Data 6 Certification and Warranty 6 1 Certification 6 1 1 Warranty 6 1 2 Limitation of War
36. ified 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 O 2012 Jackson Labs Technologies Inc Mini JLT User Manual 47 Mini JLTTM User Manual J a ck 5 on Labs 48 Remember in order to see all the data in the log file you must either set the span control to zero or right double click in the graph When you have locked the start and stop time using the mouse you can scroll left or right through the data without changing the span To scroll to a later time use Shift Left click To scroll to an earlier time use Shift Right click Double left click to release everything The time span indication at the lower right of the graph will turn red to signify that mouse override is in effect Figure 5 5 Graph display GPSCon Utility Pro GPSCon COM8 Gras dite Map ff Graph Export Help EEE SS Jackson Labs FireFly Il Firmware Rev 2 19 Life go 02 36 34 16 11 10 EFC 2 414181 ad 0m sd 0 04m J TI max ns 20 S 0 17 Temp se Jr Filter coeff 0 025 Span mins 15000 se Hide Mot Tracking 0 PRN El As 2 41396 0 13560 3 0 av 0 03n sd 11n VTC 2 36 25 16 Now 2010 Lat N 27 15 39 75
37. ingle 5V supply with 4 0V to 6 0V range and has connectors to indicate GPS and External Reference lock presence The board includes a high performance GPS receiver that can acquire and track up to 50 GPS signals down to a state of the art 160dBm a 32bit processor that runs a Real Time OS one10MHZ 5dBm legacy output one optional 10MHz 13dBm output 1PPS UTC synchronized CMOS output TTL USB or optional RS 232 serial control interfaces and precision voltage references and DACs Figure 1 1 Mini JLT GPSDO MINI JLT 8 a 3 2012 Jackson Labs Technologies Inc 1 Mini JLTTM User Manual Ja ck 5 on Labs 1 2 General Safety Precautions The following general safety precautions must be observed during all phases of operation of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Jackson Labs Technologies Inc assumes no liability for the customer s failure to comply with these requirements 1 2 1 Antenna Lightning Protector Always use a UL approved and properly installed GPS Antenna Lightning protector on the coaxial GPS antenna feed to prevent damage injury and or death in case of a lightning strike 1 2 2 Grounding To avoid damaging the sensitive electronic components in the Mini JLTTM GSPDO always make sure to discharge any built up electrostatic charge to a goo
38. interval 0 255 The command is disabled until the GPS receiver achieves a first fix This command has the following format GPS PASHR lt int gt 0 255 3 3 12 GPS GYRO 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 GPS GYRO 1 The resolution of this command is 1 20 of a second Setting the command to 0 disables the Accelerometer output This command has the following format GPS GYRO lt int gt 0 255 GPS GYRO 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 0 Degrees The worst performance with an accuracy 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
39. 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 3 6 11 SYNChronization health The SYNChronization health query returns a hexadecimal number indicating the system s health status Error flags are encoded in a binary fashion so that each flag occupies one single bit of the binary equivalent of the hexadecimal health status flag The following system parameters are monitored and indicated through the health status indicator Individual parameters are ored together which results in a single hexadecimal value encoding the following system status information If the OCXO coarse DAC is maxed out at 255 HEALTH STATUS l 0x1 If the OCXO coarse DAC is mined out at 0 If the phase offset to UTC is gt 250ns If the run time is lt 300 seconds If the GPS is in holdover gt 60s If the Frequency Estimate is out of bounds If the OCXO voltage is too high If the OCXO voltage is too low HEALTH STATUS 0x2 HEALTH STATUS 0x4 HEALTH STATUS 0x8 HEALTH STATUS l 0x10 HEALTH STATUS l 0x20 HEALTH STATUS l 0x40 HEALTH STATUS l 0x80 If the short term drift ADEV 100s gt 100ns HEALTH STATUS l 0x100 For the first 7 minutes after a phase reset or a coarsedac change HEALTH STATUS l 0x200 If the GPS receiver indi
40. ited z Interval 130 y secs Bit from display Pixels 317 Local HTML and image files HTML file c program files amp 86 gpscon gpsstat htm Browse bitmap HTML update interval 30 y secs m Satellite tracking history file Track file c program files amp 86 gpscon gpsdmp bin Browse Max kB 0 unlimited 512 Span 2020 er mins 5 3 1 1 Communication Parameters Paths 4 settings FTP Email Coms Time services Adam Aux coms Export graphics Remote control IV Log Status M Log EFC MN Log sat count M Tito GPS Log PU Translate time codes I Continuously read error queue Flash LED Use bitmap IV Statistics IV Show best fit to EFC T ANSI font in status IT Timax g ns Filter coeff 0 025 Before you can use GPSCon you must set the communication parameters for your system Open the dialog box by pressing the Options button Then select the Coms tab You will see the window shown in Figure 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 3 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 exampl
41. l be applied immediately to the GPS receiver and are stored in Non Volatile memory 3 3 16 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 15 This state can be different from the user selected Dynamic model mode for two reasons 1f 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 if the GPS Timing Mode is set to ON or to RSTSURV the dynamic state will always be set to 1 Stationary 3 3 17 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 betw
42. low 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 29 GPS JAMlevel Firmware revision 2 32 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 and loss of the 1PPS signal from the GPS will cause a SYNC HEALTH 0x800 event to be flagged and the unit to disable the LOCK_OK signal on connector J3 22 O 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM User Manual Labs 3 3 30 GPS FWver This command queries and returns the Firmware version used inside the GPS receiver itself 3 3 31 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 on the Mini JLTTM unit GYRO MODE lt ON OFF gt GYRO TRACE lt int gt 0 255 GYRO CALibrate lt float float float float float float gt GYRO CALibrate COMPute GYRO CALibrate RESET GYRO SENSitivity lt float float float gt GYRO EFC lt 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 Similar
43. m RS 232 serial levels on connector J1 as the default configuration is TTL level Both the TTL serial port J1 and the USB port are internally ored together so the user may send and receive commands to from both ports as long as commands are not sent to both ports at the same time Try some of these SCPI commands help syst stat GPS sync meas 2 1 1 PCB Photos The Mini JLT PCB is shown in Figure 2 1 Figure 2 1 Mini JLT Single Oven PCB m 5 SN 7 EN r s A bk GPS Antenna In 2 SMINI JLT R gun sg A A 10MHz 5dBm Out i Power and Serial Port f TR A La O 7 i d En 0 1PPS Out 1 r a 7 NR 10MHz 13dBm Out e use y sane Be Le ER LOCKOK EVENTE ISP SH M and GPS Fix OK Connector ii ei A ear EE i i BE SS 2 1 2 Mechanical Drawings The following drawings show the mechanical dimensions and the pinout of the Mini JLTTM PCB 4 2012 Jackson Labs Technologies Inc Jackson Ke Figure 2 2 Mini JLT Mechanical Dimensions Mini JLT User Manual laas 1 050 1 025 Table 2 1shows the Mini JLT revision 1 0 hardware pin descriptions Table 2 1 Mini JLT hardware connectors
44. mmand 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 OCXO warmup 1 Holdover 2 Locking OCXO training 4 Value not defined 5 Holdover but still phase locked stays in this state for about 100s after GPS lock is lost 6 Locked and GPS active O 2012 Jackson Labs Technologies Inc 33 Mini JLTTM User Manual J a ck 5 on Labs 3 10 13 SERVo This command returns the result of the following queries SERVo COARSeDac SERVo DACGain SERVo EFCScale SERVo EFCDamping SERVo SLOPe SERVo TEMPCOmpensation SERVo AGINGcompensation SERVo PHASECOrrection SERVo 1PPSoffset SERVo TRACe Ab 0 KT E ke 34 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLTTM User Manual Labs Firmware Upgrade Instructions 4 1 Introduction The following is a short tutorial on how to upgrade the Mini JLT GPSDO firmware Please follow the instructions in order to prevent corrupting the Mini JLT 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 There are two Flash loader utilities available to upgrade the Mini JLT firmware You can download the Philips LPC2000 utility f
45. mmunications Select Device 8 Erase block D 0x000000 0x000FFF Erase block 1 0x001000 0x001FFF COM Port 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 Rd Prot Oscillator MHz V1 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 4 will appear 2012 Jackson Labs Technologies Inc 39 Mini JLTTM User Manual Ja ck 5 on Labs Figure 4 4 Device selection window Flash Magic NON PRODUCTION USE ONLY Die SP Options Tools Help EATA HOLC ARM Cortex LPC900 2 clock 80C51 80051 Technical on line articles about 8051 and 4 programming www esacademy com fag docs C Expand the ARM7 folder and select the appropriate processor in this case the LPC2138 40 2012 Jackson Labs Technologies Inc Jacks on Mini JLT User Manual Labs Figure 4 5 Expanded device selection window File ISP Options Tools Help 4028 lt 96 LPC2101 LPC2102 LPC2103 LPC21
46. nc 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 2012 Jackson Labs Technologies Inc 51 Mini JLTTM User Manual Ja ck 5 on 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 DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY 52 2012 Jackson Labs Technologies Inc
47. o EFCScale parameter For example if we set SERVo FASTlock to 2 and SERVo FALEngth to 3600 and SERVo EFCScale is set to 0 7 Then initially the unit will multiply the EFCscale by 2x and an effective EFCscale value of 1 4 is applied to the PLL loop This increased gain value difference will be reduced every second by 1 3600 so that the gain after two seconds would be 1 3998 until after 3600 seconds the gain has been reduced back to its long term value of 0 70 as stored in the SERVo EFCscale parameter Disabling the FASTLOCK mode is accomplished by setting the SERVo FASTlock to 1 This will set the dynamic gain to 1 0 effectively disabling the fastlock feature This command has the following format SERVo FASTlock lt int gt 1 20 3 10 2 SERVo FALEngth This command adjusts the length of time during which the FASTLOCK feature is active please see the command SERVo FASTlock above It can be set from 100 seconds to 20 000 seconds The Dynamic FASTLOCK gain is slowly reduced until it reaches a gain of 1 0 after the FALEngth period of seconds During this time the PLL loop gain is increased by the amount specified in the SERVo FASTlock parameter which will result in a faster initial phase lock to UTC after power on while giving the lowest possible noise floor best short term stability during normal operation This command has the following format SERVo FALEngth lt int gt 100 20000 2012 Jackson Labs Technologies Inc 31
48. o GPS can drive 50 Ohms end terminated cables 2 1 3 Notes on Signal Interfacing The optional LOCK_OK_OUT is a 3 3V LVCMOS signal and thus require a series resistor of typically 390 to 470 Ohms when used to drive an external LED The serial port RX and TX lines cannot be directly connected to a DB9 connector as these are driven with TTL signal levels Connecting these pins to an RS 232 serial interface may damage the board 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs The SCPI and NMEA outputs are sent to both the TTL serial output and the USB output and the SCPI control commands can be sent to either the TTL serial port or the USB serial input both signals are ored together on the board Commands can thus be sent to the board via both ports but should not be sent to the TTL serial port and the USB serial port simultaneously as this will result in non destructive garbling of the serial transmission Connect an active or passive L1 GPS antenna that is compatible to 3 3V or 5V antenna power and connect this antenna prior to turning on the board Use a lightning arrestor on the antenna feed for safety and to prevent damage injury or death in case of a lightning strike 2 1 4 Coaxial Connectors The GPS antenna connector the 1PPS connector and the 1OMHz connectors on the Mini JLT board are generic SMA types 2 2 Power The unit is powered from a 4 0V to 6V DC source with
49. ol voltage to be lowered to maintain 10 0MHz exactly A drift of 2mV is visible over 200 hours On the left side of the screen the EFC range over this 200 hour plot is displayed vertically as 0 00193V This means the drift of the EFC voltage due to aging is 88mV per year The EFC sensitivity of the crystal is about 8Hz per volt so the crystal ages at 8Hz V 0 088V Year 0 704Hz Year drift At 10MHz 0 704Hz 10MHz 7 04E 08 aging rate per year This is the same as 0 2ppb drift due to aging per day This crystal aging is fully compensated by the firmware with and without GPS reception of course The OCXO heater current is shown in turqoise We can see it ranges from 0 135607A to 0 178146A The OCXO current jumps lower every 24 hours because the unit is sitting next to a window and the sun shines onto the OCXO in the evenings heating it up and thus making the unit use lower power during that event In Figure 5 6 which is a zoom of Figure 5 5 we can see the phase offset error of the internal OCXO to the UTC GPS reference We can see the maximum drift is 77ns to 93ns The average is TI av 0 03ns The standard deviation over the 200 hour plot is sd 11ns This means the average error of the 1OMHz phase of this unit over 200 hours is only 11ns rms Or in other words the average jitter wander over 200 hours of operation is 11ns 200Hrs 1 528E 014 or in other words the unit performs as well as a high quality Cesium Atomic ref
50. ommand instructs the Mini JLT to send the NMEA standard string GPZDA every N seconds with N in the interval 0 255 The command is disabled until the GPS receiver achieves a first fix This command has the following format GPS GPZDA ant 0 255 3 3 11 GPS PASHR The NMEA string PASHR POS has been added for compatibility to legacy GPS hardware 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 Ox0d sta termination characters PASHR POS 0 aa bbbbbb 00 cccc ccccc d eeeee eeeee f ggg 9 92 hhhh iii ii jjj jj kkkk kk IL 1 mm m mn n 00 0 p pp checksum Where aa Number of Sats bbbbbb 00 Time of Day UTC cecc 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 IL 1 PDOP mm mHDOP 2012 Jackson Labs Technologies Inc 15 Mini JLTTM User Manual Ja ck 5 on Labs nn nVDOP 00 0Static number p pp Firmware Version 1 05 and above This command instructs the Mini JLT to send the NMEA standard string PASHR every N seconds with N in the
51. over RECovery INITiate Bo 0 3 6 4 SYNChronization SOURce MODE 26 3 6 5 SYNChronization SOURce STATE 26 3 6 6 SYNChronization TINTerval 26 3 6 7 SYNChronization IMMEdiate 26 3 6 8 SYNChronization FEEstimate 26 3 6 9 SYNChronization LOCKed 2 E 86 3 6 10SYNChronization OUTput 1PPS RESET IONIOFF OT 3 6 11SYNChronization health 3 6 12SYNChronization 28 3 7 DIAGnostic Subsystem Mn SAND a Ae 4128 3 7 1 DIAGnostic ROSCillator EFControl RELative 3 7 2 DIAGnostic ROSCillator EFControl ABSolute 28 3 7 3 DIAGnostic LlFetime COUNt2 28 3 8 MEASURE Subsystem 28 3 8 1 MEASure VOLTage 29 3 8 2 MEASure CURRent 29 3 8 3 MEASure m aomp m a a e 29 3 9 SYSTEM Subsystem i RE ey RE NS A ei e 3 9 1 SYSTem COMMunicate DEE 2 9 3 9 1 1 SYSTem COMMunicate SERial ECHO a due a 4 9 3 9 1 2 SYSTem COMMunicate SERial PROMpt 29 3 9 1 3 SYSTem COMMunicate SER
52. owing format SYNChronization SOURce MODE GPSIEXTernallAUTO 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 Mini JLT 1 PPS and the GPS 1 PPS signals The resolution is 1E 10 seconds 3 6 7 SYNChronization IMMEdiate This command initiates a near instantaneous alignment of the GPS 1 PPS and Receiver output 1 PPS To be effective this command has to be issued while not in holdover 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 26 2012 Jackson Labs Technologies Inc Mini JLT User Manual Jackson Ke 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 O OFF 1 ON of the PLL controlling the TCXO 3 6 10 SYNChronization 0UTput 1PPS RESET ON OFF 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
53. pin 2 of 15 to allow in field firmware upgrades on the Mini JLT PCB Both LED 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 4 4 Downloading the firmware Download the latest version of Mini JLT 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 TTL serial port prior to firmware download The Mini JLT is TTL level compatible A TTL to RS 232 converter must be used when connecting to the computer s RS 232 serial port to prevent damage to the board Connect a USB or TTL serial connector to the Mini JLTTM as indicated in Section 2 1 1 The units firmware may also be updated through the USB connector serial port 4 4 1 Philips LPC2000 Flash Utility A Open the LPC2000 utility Set the COM port in the LPC2000 application as needed on your PC B Select the Baud Rate of the LPC2000 utility to be 38400 or slower Faster Baud rates will not work properly C Press the READ DEVICE ID button this should then show LPC2138 in the DEVICE window if the unit is communicating correctly to the application Warning Make sure NOT to press the erase button under any circumstances this may erase factory calibration data and the unit will not operate and will have to be returned to the fac
54. ported for this subsystem is the following SYNChronization SOURce MODE GPSIEXTernall AUTO SYNChronization SOURce STATE SYNChronization HOLDover DURation SYNChronization HOLDover STATe SYNChronization HOLDover INITiate SYNChronization HOLDover RECovery INITiate SYNChronization OUTput 1PPS RESET ONIOFF SYNChronization TINTerval SYNChronization IMMEdiate SYNChronization FEEstimate SYNChronization LOCKed 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 holdover The second number in the response identifies the holdover state A value of 0 indicates the Receiver is not in holdover a value of 1 indicates the Receiver is in holdover 2012 Jackson Labs Technologies Inc 25 Mini JLTTM User Manual J a ck 5 on Labs 3 6 2 SYNChronization HOLDover INITiate The SYNC HOLD INIT and SYNC HOLD REC INIT commands allow the user to manually enter and exit the holdover state even while GPS signals a
55. ranty 6 1 3 Exclusive Remedies 2012 Jackson Labs Technologies Inc Mini JLT User Manual 31 31 32 32 32 32 32 32 2 33 33 Mini JLTTM User Manual J a C k 5 on Labs 4 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs Introduction 1 1 Overview Jackson Labs Technologies Inc designed the Mini JLT board to address a market demand for replacing the end of life Trimble Navigation Limited Mini T GPSDO units used in existing customer projects The board was designed to be form fit function compatible to the Trimble units with the exception of adding various features such as a 1PPS external input 3 axis on board accelerometer USB communication internal antenna power supply wide range main power supply extended temperature range lower overall height 0 8 inches vs 0 5 inches above the PCB and a significantly improved thermal stability Allan Deviation and Phase Noise performance The unit also adds support for NMEA and SCPI communication commands and removes support for TSIP proprietary commands The Mini JLT GPSDO uses a GPS receiver that can run in stationary Position Hold mode and mobile mode to discipline an OCXO local oscillator to better than I ppb frequency accuracy It supplies two 1OMHz outputs The board includes both TTL level RS 232 serial levels optional and USB serial control ports for NMEA and SCPI communication The board operates from a s
56. re 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 OCXO drift when not locked to GPS for testing purposes or to prevent the GPS receiver from being spoofed and affecting the OCXO 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 3 6 4 SYNChronization SOURce MODE The Source Mode command allows an optional external 3 3V 5V level 1PPS input to be connected to the Mini JLT board on pin 1 of connector 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 foll
57. requency output to the US Naval master clock for very high frequency accuracy typically better than 10 digits of frequency accuracy when locked to GPS 2 4 Remote serial control The unit is controlled via the TTL or USB serial port at 115200 baud 8N1 Other Baud Rates can be set via SCPI commands Attach the Mini JLT unit to your PC s Hyperterminal the optional GPSCon software package see 2012 Jackson Labs Technologies Inc 7 Mini JLTTM User Manual Ja ck 5 on Labs Chapter 5 of this manual or a third party freeware Windows based application program called Z38XX The Z38xx program can be used to track the performance of the Mini JLTTM Z38xx is available on the Jackson Labs Technologies Inc website under the following URL http www jackson labs com assets uploads main Z38XX zip 2 5 Loop parameter adjustment All loop parameters can be controlled via either of the two serial ports Loop parameters are optimized for the TCXO on the board and changing the factory settings may result in the unit s performance to deteriorate The commands to control the loop parameters are part of the servo command See also the SERVO Subsystem section 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 good double oven OCXO and 6
58. rom the Jackson Labs Technologies Inc website under the Support tab http www jackson labs com support html The Flash Magic utility is available for download on the Flash Magic website http www flashmagictool com 4 2 1 Philips LPC2000 Flash Utility The first is the Philips LPC2000 utility version 2 2 3 Please note that some computers are known to be incompatible with the LPC2000 flash utility Preliminary investigations show Windows Media Center and or Centrino vPro processor systems to create download difficulties Please use a different computer if you experience problems such as the download breaking up in the middle of the transfer Or alternatively you may use the Flash Magic programming tool Please ensure that you have at least version 2 2 3 of the LPC2100 flash utility installed Earlier versions may not recognize the LPC2138 processor used on the Mini JLT boards O 2012 Jackson Labs Technologies Inc 35 Mini JLTTM User Manual Ja ck 5 on Labs 4 2 2 Flash Magic Flash Programming Utility The second utility 18 the Flash Magic tool available on the Flash Magic website http www flashmagictool com If the Philips LPC2000 tool doesn t work please use this one 4 3 Putting the PCB into In Circuit Programming ISP mode Momentarily short out the ISP pin 2 of header JS to pin 1 of header J5 of the Mini JLT board to ground the ISP pin during power on It may be useful to connect a push button to pin 1 and
59. t gt 100 0 100 0 SERVo 1PPSoffset lt int gt ns SERVo QUIet lt ON OFF gt SERVo TRACe lt int gt 0 255 SERVo FASTlock lt int gt 1 20 SERVo FALEngth lt int gt 100 20000 SERVo 30 2012 Jackson Labs Technologies Inc Ja ck 5 on Mini JLT User Manual Labs 3 10 1 SERVo FASTlock The FASTlock command enables the FASTLOCK mode and sets its gain parameter Fastlock works by momentarily multiplying the EFCScale gain to a value determined by this SERVo FASTlock parameter Gain values of 1x to 20x can be set with a gain of 1x effectively disabling the FASTLOCK feature By selecting gain values of gt 1 the PLL loop parameter Proportional gain SERV EFCscale will be increased after power on thus increasing loop aggressiveness and improving lock PLL time It is not desirable to maintain a high loop gain for longer than necessary to lock the PLL since high loop gains come at the expense of increased phase noise reduced short term stability The FASTLOCK mechanism will automatically reduce the FASTLOCK gain over a period of time specified by the SERVo FALEngth command during which time the FASTLOCK gain is slowly decreased from its initial value to 1 0x Setting the FASTLOCK gain to 2 for example will result in the Proportional gain value stored in the SERVo EFCscale parameter to be multiplied by 2x initially after power on This dynamic gain is slowly reduced until the gain is back to 1 0x the value stored in the SERV
60. the last survey 3 3 26 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 3 3 27 GPS INITial DATE lt yyyy mm dd gt Firmware revision 2 32 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 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 28 GPS INITial TIME lt hour min sec gt Firmware revision 2 32 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 al
61. 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 3 13 GPS GYRO CAL This command calibrates the output period of the Accelerometer data in g s per axis and in tilt in Degrees per axis Both offset and gain need to be calibrated on the unit to properly format the output of the three axis tilt to be 90 Degrees to 90 Degrees and the 0 Degree reference By default the unit is shipped with a normalized output of 0 Degrees Offset and a gain of 1 0 and the user will need to calibrate their unit in their system 16 2012 Jackson Labs Technologies Inc J a ck 5 on Mini JLT User Manual Labs This command has the following format GPS GYRO CAL lt float gt lt float gt lt float gt lt float gt lt float gt lt float gt Calibration is accomplished by slowly tilting the unit on all six axis and measuring the maximum and minimum tilt indications in all six axis and writing these down on a piece of paper to calculate the calibration values Later firmware releases may automate this process Example if the result for say the X axis is 87 Degrees to 93 Degrees then we need to remove an offset of 3 Degrees from the X axis while the gain of the X axis is properly set We would thus send the following calibration command to the unit GPS GYRO CAL 3 0 0 1 1 1 This will remove a 3 Degree offset
62. ting 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 value of zero causes the export to take the same setting if any as the screen display The export may be done automatically on a timed basis Simply enter a non zero value in seconds to choose an export time interval To manually export in accordance with the settings press the Export button 2012 Jackson Labs Technologies Inc 49 Mini JLTTM User Manual Ja ck 5 on Labs 5 4 Interpreting the Data Figure 5 5 shows the data acquired by the Mini JLTTM unit over a period of more than 200 hours The red trace is EFC crystal frequency control voltage The crystal is aging becoming faster in frequency over time This requires the contr
63. tory Pressing the erase button on the ISP utility will thus void the warranty 36 2012 Jackson Labs Technologies Inc J a ck 5 0 n Mini JLT User Manual Labs Figure 4 1 LPC2000 flash utility f LPC2000 Flash Utility File Buffer Help PHILIPS LPC2000 Flash Utility V2 2 3 r Flash Programming Erase Blank r Communication Filename Connected To Pott CAARMiFury_GPSDO ApplicationimainFur Blank Check Entire Device come D Upload to Flash pr Execute Code Use Baud Rate pload to Flas eer 7 Start Sector 38400 z Selected Sectors atter Upload Erase Compare Flash Manual Reset gt Time Out sec 2 r Device Use DTR ATS Device ES Part for Reset and Boot Loader TAL Freq kHz f10000 Device ID Boot Loader 10 Selection Please note that the Use Baud Rate setting needs to be set to 38400 Baud or less it will not work faster than 38400 Baud The DEVICE should show up as LPC2138 after pressing READ DEVICE ID Also please point the Filename to the directory where you have stored the latest firmware hex file that is to be downloaded D Start the download by pressing Upload to Flash button The following window should appear if the correct COM port has been chosen etc O 2012 Jackson Labs Technologies Inc 37 Mini JLTTM User Manual J a C k 5 on Labs Figure 4 2 LPC2000 flash download
64. ut 22 40 07 28 10 10 UTC Receiver timeout 22 40 23 28 10 10 UTC Receiver timeout 22 42 17 28 10 10 UTC Receiver timeout 5 3 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 update cycle the selected span 1f 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 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 magn

Download Pdf Manuals

Related Search

Related Contents

ASUS Asus Rampage IV Extreme RAMPAGEIVEXTREME User's Manual  Quentin Drouet  Válvula de esfera M10P Roscadas y preparadas para  Sony BDVE780W Stereo System User Manual    Oreck IronMan IM90 User's Manual  Euro-Pro 372 Sewing Machine User Manual  

Copyright © All rights reserved. Failed to retrieve file