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Telit Wireless Solutions SL869-T User Manual
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Telit Wireless Solutions SL869-T User Manual

Telit Wireless Solutions SL869-T User Manual

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Summary of Contents for Telit Wireless Solutions SL869-T

  • Page 3 SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE Notice While reasonable efforts have been made to assure the accuracy of this document, Telit assumes no liability resulting from any inaccuracies or omissions in this document, or from use of the information obtained herein.The information in this document has been carefully checked and is believed to be entirely reliable.
  • Page 4 Usage and Disclosure Restrictions License Agreements The software described in this document is the property of Telit and its licensors. It is furnished by express license agreement only and may be used only in accordance with the terms of such an agreement. Copyrighted Materials Software and documentation are copyrighted materials.
  • Page 7 Non-Disclosure Agreement to use timing module firmware and is a supplement to other SL869 software user guides. This document is intended only for distribution to Telit employees and to SL869-T GNSS timing module customers who have signed a Non-Disclosure Agreement (NDA) with Telit Wireless.
  • Page 8 SL869-T. “Chapter 4: “Messages Description” describes in detail each of the output messages related to timing which are produced by the SL869-T. “Chapter 5: “Document History” provides of the changes made to this User Guide. Danger – This information MUST be followed or catastrophic equipment failure or bodily injury may occur.
  • Page 9 The SL869-T timing module is a member of the SL869 product family that is intended for use in timing applications. The timing firmware within the module provides an accurate PPS signal by holding an internal reference position that represents the location of the antenna for the timing module, and then by applying satellite measurements only to the calculation of time.
  • Page 10 (e.g. a $PSTMHOT command) while the auto-survey algorithm is underway, the algorithm is restarted. If the antenna position is accurately known a priori when the SL869-T timing module is installed, the module can be commanded into Position Hold mode and to specifiy the antenna position as its held reference position.
  • Page 11 The table below lists the commands used for managing the timing feature, and that are available to authorized users of the SL869-T timing module. These commands are echoed by the SL869-T back to the Host after the command is executed.
  • Page 12 8 digits to 100000 If the OnOff field is set to ‘1’ and the command is successful, the SL869-T uses the position provided in the command as the reference position and responds with the following message: $PSTMPOSITIONHOLDENABLED*49<cr><lf>...
  • Page 13 Enable Position Hold: $PSTMENABLEPOSITIONHOLD,1,3340.2555,N,11739.2333,W,255.55*06 This command is used to manage the PPS output of the SL869-T and is described in the Software Authorized User Guide. The command types described in the subsections below can be used to set and get information about the Position Hold and TRAIM features and are supplemental to the command types supported by standard firmware.
  • Page 14 TRAIM algorithm and are not used for timing correction. Also, if the average time error exceeds the alarm threshold, the Status indicates an OVER alarm condition. By default the SL869-T uses an alarm threshold of 15 nanoseconds. This command can be used to poll for the satellites used for timing.
  • Page 15 The response to this command has the following format: $PSTMPPS,1,16,<Enabled>,<UsedSats>,<Sat1>,...,<SatN> *<checksum><cr><lf> Parameter Format Description 0 – TRAIM is disabled Enabled One digit decimal 1 – TRAIM is enabled UsedSats Decimal Number of satellites used by the TRAIM algorithm Sat1…SatN Decimal List of used satellite IDs Example: $PSTMPPS,1,16,1,5,31,22,14,32,20*53...
  • Page 16 The response to this command has the following format: $PSTMPPS,1,18,<Enabled>,<RemovedSats>,<Sat1>,...,<SatN> *<checksum><cr><lf Parameter Format Description 0 – TRAIM is disabled Enabled One digit decimal 1 – TRAIM is enabled RemovedSats Decimal Number of satellites removed by the TRAIM algorithm Sat1…SatN Decimal List of removed satellite IDs Example: $PSTMPPS,1,18,1,2,31,1*41...
  • Page 17 If Samples is set to 0, the algorithm is disabled. Otherwise, if a non-zero value is provided and the SL869-T is not in Position Hold mode, the algorithm is restarted using the specified number of position samples. It is recommended that the number of samples should be chosen to allow the algorithm to run for one hour or longer.
  • Page 18 Note 1: TRAIM messages are all controlled by the same bit. Example: Enable output of the $PSTMPOSHOLD message: $PSTMSETPAR,1201,4000000,1 The message will be output after the SL869-T is given a software reset command (e.g. $PSTMHOT) or the setting is saved to flash.
  • Page 19 In order for the new default Position Hold state to become Disabled, it must be saved to flash. If the module is in Position Hold mode, the SL869-T must then be rebooted to use the new default and disable Position Hold.
  • Page 20 $PSTMSETPAR,1215,<Samples><cr><lf> and then saving to flash. Note that the specified number of samples takes effect when the parameter is saved to flash. Please refer to section 3.2.7 for more information regarding the use of this value. Example: Configure the position auto-survey to run for one day (24 hours) from start-up by default: $PSTMSETPAR,1215,15180...
  • Page 21 The table below summarizes the messages that are related to the timing feature and are output periodically by the SL869-T. These messages are available to authorized users of the SL896 Timing firmware. Message ID Description $PSTMPOSHOLD Position Hold status and reference position...
  • Page 22 This proprietary message reports the status of the Position Hold feature which is used for timing. If Position Hold is enabled, the held reference position is also reported. Format: $PSTMPOSHOLD,<OnOff>,<Lat>,<N/S>,<Long>,<E/W>,<Alt>*<checksum> <cr><lf> Parameter Format Description 0 – Position Hold is disabled OnOff One digit decimal 1 –...
  • Page 23 This proprietary NMEA message reports the status of the TRAIM algorithm. Format: $PSTMTRAIMSTATUS,<OnOff>,<Status>,<Alarm>,<AvgError>, <UsedSats>,<RemovedSats>,<RefSecond>*<checksum><cr><lf> Parameter Format Description 0 – TRAIM is Off OnOff One-digit 1 – TRAIM is On Decimal 0 – UNDER alarm Status One-digit 1 – OVER alarm Decimal 2 - UNKNOWN Alarm...
  • Page 24 This proprietary NMEA message reports the satellites that are being used for timing correction. Format: $PSTMTRAIMUSED,<OnOff>,<UsedSats>,<Sat1>,...,<SatN>*<checksum> <cr><lf> Parameter Format Description 0 – TRAIM is Off OnOff One-digit Decimal 1 – TRAIM is On UsedSats Decimal Number of satellites used for timing correction Sat1…SatN Decimal List of used satellite IDs...
  • Page 25 Example: Given the $PSTMTRAIMUSED example above, this example shows residuals for PRNs 22, 6, 18, 15 and 3, respectively. $PSTMTRAIMRES,1,5,-21,-7,22,-6,-9*0E This proprietary NMEA message reports the satellites that have been removed from use for timing correction. Format: $PSTMTRAIMREMOVED,<OnOff>,<RemovedSats>,<Sat1>,...,<SatN> *<checksum><cr><lf> Parameter Format Description 0 –...
  • Page 26 Revision Date Changes 2013-09-24 Draft issue 2013-10-28 Re-wrote Section 2 as an Overview. Added $PSTMPPS command types related to TRAIM. Added $PSTMSETPAR command for controlling output messages related to timing. 2014-10-01 Expanded introductory section on internal reference position (auto-survey, resets, etc.). Added details on use of no. of samples, added example for 24 hour survey.