Summary

GT-NS/GT-DM is unresponsive or frozen.

Cause

Possible reasons:

1. The R1/R2 conductors are shorted or disconnected (GTA/V-DES or GT-DM).
2. The GT-NS is disconnected from the GT-DA, or the GT-DA is malfunctioned (GTA/V-DES).
3. The GT-NS has malfunctioned caused by a possible power surge (GTA/V-DES).

Solution

First ensure proper connection on R1/R2 and confirm 24V DC on the line.

If the R1/R2 is correctly connected, and power is verified, change the appropriate dip switches (shown below – GT-NS:SW1- Switch 4 or with the GT-DM: SW2 – Switch 1) on (or in the up position. This will cause the GT-NS or GT-DM to work independently of the R1/R2 path. It will then be able to determine if it is the GT-NS or the GT-DA (GTA/V-DES) that needs possible repair or replacement.

GT-NS

GT-DM