There are two options available to enable the PPS output from the LD2 fitted with a Topcon GPS card.
Warning: This procedure is for LD2 units equipped with Topcon GPS receivers only. It will NOT work with Ashtech equipped units.
Using Topcon PC-CDU software to check the PPS status on the LD2 and configuring the PPS/ZDA output. A document outlining the procedure to do this is available at the bottom of this article.
Topcon script files, are available from Veripos Helpdesk which will enable the LD2 to output a ZDA with a 1PPS on port 1 of the LD2.
To upload the file, connect a PC using a serial port (preferably not using a digi port) to port 5 or Port 3 (if Port 3 switch is fitted to rear panel) of the LD2, ensure that port 5 of the LD2 is set to "REMOTE" mode (Configuration - Serial Ports - P5) or ensure Port 3 switch is set to GPS. Open PCCDU on the PC and connect. In the menu's go to File - Manual Mode. This will open a dialog box, select "Load Script" and navigate to the location of the script file and press open. Then select the "send script" button. You should see the script load on the screen.
This should enable the 1 second PPS and ZDA on port 1 of the LD2.