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Spirent TestCenter: What connections are needed between the Chassis and the Symmetricom TP-5000 GPS receiver?

Environment/Versions
  • Spirent TestCenter
  • External Timing Reference - Symmetricom TP5000

 

Answer
  • When an external timing reference (ETR) is needed for GPS setup, 3 connections are needed.
    • The 10Mhz
    • 1PPS and
    • AUX/CRAFT serial connection.
  • The two coax/BNC connections are for clock signals (10Mhz / 1PPS).
  • We should be using a Null-modem serial cable (Not a straight-through cable) which carries the time-of-day (ToD)
  • On the TP5000 unit/modules, the serial port is labeled 'CRAFT'.
    • Baud rate on the TP5000 'CRAFT' port should be set at 56kbps, if not already defaulted to.
  • You must also configure the Spirent TestCenter chassis to communicate with a TP5000 device.
    This is done by the following steps:
    1. Telnet or console to the Spirent TestCenter chassis (Console configuration is 9600-8-n-1 & No Flow control)
    2. Enter 'etr device TP5000' (This ensures the chassis does not have to search for a device by using different baud rates and commands)
      • Enter 'etr devname' or 'etr device'  (If we have "TP5000" returned, we can verify that the device was excepted by the chassis firmware)
      • If/when getting ETR status-related errors (i.e. 'Error: unknown status fe', 'Error while waiting for response'), please double check the 'AUX'/'CRAFT' connection.
  • Notes:
    • If you connect to the TP5000 to the Spirent TestCenter chassis before setting the 'etr device TP5000' command, you may need to reboot the TP5000 and wait for it to lock/calibrate to the satellites again.
    • The first release of the Next Generation SPT-N11U chassis did not support the TP5000 yet. v4.31
    • Tested in v4.33 and TP5000 shows Successfully Established Connection.

Product : Chassis,Spirent TestCenter