Changing the value of a DS54 Configuration Variable with a DT400 is easy if you follow the steps listed below.
1) Disconnect the DS54 from the LocoNet, aux power source, all inputs and all outputs.
2) Short the pins of the Enable Link.
3) Connect the DS54 track terminal inputs to the isolated programming track.
4) Connect the yellow (feedback) wire from any DS54 Output (A, B, C or D) to either rail of the isolated programming track.
5) DT400 Programming Steps:
6) Remove the yellow feedback wire connecting the output connector to the isolated programming track.
7) Remove the wires connecting the track terminals to the isolated programming track.
8) Open the pins of the Enable Link.
9) Connect the DS54 to the respective inputs, outputs, rails, aux power, and LocoNet.