DTM30: How does it know the point positions?

Digitrax command stations invoke an "interrogation" sequence after power up. Accessory decoders and other devices that are connected to LocoNet (e.g. DS54, DAC20, DS64, BDL168, SIGM20) will report the positions of their outputs.

  • Points driven by LocoNet accessory decoders (e.g. DAC20, DS64) will report positions if "turnout feedback" microswitches are used.
  • Points driven by a DAC20 will also report positions even if no turnout feedback microswitches are used.
  • BDL168 type sensors report automatically, so LEDs for them will light up
  • Sensors connected to LocoNet accessory decoders (e.g. DAC20, DS64) will report automatically, so their LEDs will light up
  • Signals controlled by SIGM20 report automatically, so their LEDs will light up.

If you have points driven by a non-LocoNet accessory decoder, then the LEDs will not light until the position is known. Using the panel pushbutton or a throttle will change the point and its LED will light.

The DTM30 does have an "initialise" feature: by using one push button, all connected points can be driven to a known state. For a layout without DAC20 or without wired position feedback, this may be the simplest option to get up and running.