GPS Time Synch Problem

Version 3

    Several customers have seen a problem with their GPS time source showing the wrong time after Feb 13, 2016.  (The date now shows in 1996).

    The manufacturer of the Trimble GPS cards has acknowledged that this bug is in their cards with more details below.  See the attached file for their bulletin. 

    This problem has been identified with the Extended GPS Week Number in the 0x41 message and the Week Number in the 0x8F-20 message on certain legacy Trimble products.

    The week numbers will be incorrect after February 13th 2016.


    Problem Description

    On the products listed in the table above the extended week number in the 0x41 message and the week number in the 0x8F-20 message will be incorrect after 13th February 2016.

    The week number will roll back to 860 and then increment weekly from that value.

    In addition the user should note that after the rollover to WN# 860 the GPS module will lose GPS tracking for a period of approximately 2 hours. The modules will not output their position for this period.

    This is due the Ephemeris data on the GPS receiver being incorrect for the new 860 week number. The module will restore GPS tracking when a new Ephemeris is received 2 hours after the rollover.


    From the Manufacturer

    The modules identified in the table above cannot be re-flashed with new firmware. Any check for the TSIP week number will need to be carried out by the host program.

    The user should check the extended week number value and IF < 1800, ADD 1024.

    There are no direct replacements for the hardware available from Trimble.

    Please discuss SKII and Lassen LP replacements with your local Trimble representative.



    Our suggestion is to change your primary time source from the Trimble GPS to your SCADA Master while we make a patch in our firmware.  We apologize for the inconvenience and are working to resolve the problem as quickly as possible.


    The new firmware that addresses this issue for the C3414 CPU is now available on our website at this link.  C3414-500-S02K0_P3_Firmware_Update

    Update 2:

    The new firmware update which addresses this issue for the C3413 CPU card is now available on our website at this link.