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GPS Receiver Firmware Identification

This procedure attempts to identify the chip-set within a GPS receiver and, for Trimble-based units, the firmware revision installed.


This procedure is suitable for use in two scenarios. When used with the following digitisers and instruments:

  • DM24S3EAM
  • DM24S3AM
  • DM24S6EAM
  • DM24S6AM
  • Affinity
  • 3TDE
  • 40TDE
  • 5TCDE

it will attempt to identify the GPS receiver currently being used for synchronisation. No re-cabling is required and the procedure can be used on a running system.

In addition, with the use of an additional cable, GSL part number CAS-DCM-0001, an off-line receiver can be connected to Port A or Port B of any EAM or EAM-U, in addition to all of the systems listed above (other than the Affinity).

The procedure

The procedure as documented below assumes:

  1. that the digitiser being used has a direct, functioning connection to the public Internet. If this is not practical, the script can be downloaded using a PC and transferred to the digitiser using any suitable method. Be very careful not to introduce DOW/Windows-style line endings during any file-transfer operations;

  2. that the user is contacting the digitiser using a Windows PC using the PuTTY terminal emulator. Any emulator can be used and it should be clear how to adapt the instructions in order to use a different emulator, if desired. PuTTY can be downloaded from Linux users may prefer to use the ssh command from a terminal window.

Start by opening your terminal emulator and entering the IP address of the digitiser into the "Host Name (or IP address)" field, as shown:

then click the Open button.

If this is the first time that you have used the emulator to contact this digitiser, you may get a warning about an uncached host key:

Simply click the Yes button to continue.

In addition, Windows Defender may ask whether you wish to allow this software to make connections:

Again, simply click the Allow Access button to continue.

You should then be prompted for the login user: type root

You should next be prompted for the root password; note that this will not be echoed as you enter it.

Once logged in, enter the command


to download the required script. This step depends on a correct network configuration (including the DNS server and default gateway) and a routed connection to the public Internet. If this is not practical, you can download the script to an Internet-connected PC and then transfer it to the digitiser using scp. If you have problems with this step, please contact for advice.

Once the script is downloaded, enter the command

sh PortC

and the script will attempt to identify the currently-connected GPS receiver.

If you are using an Affinity, enter GPSPort in place of PortC in the command above.
If you are using a CAS-DCM-0001 cable to connect a GPS receiver to a different port, enter the correct port name (e.g. PortA or PortB) in place of PortC in the command above. Note that you cannot use an Affinity in this way.

In the example above, the script has identified a Trimble Lassen SQ running firmware version 1.06. According to information received from Trimble, the Lassen-based GPS receivers will experience problems at the following dates:

Receiver chip-set Firmware Failure date
Lassen SQ V1.04 27th July, 2019
Lassen SQ V1.06 27th July, 2019
Lassen iQ V1.16 13th September, 2022

If the script reports a firmware version not listed above, please contact for advice.