1. Setting the sensor numbers

The “sensor board number” needs to be set to a number between 1 & 256. It needs to be different from any other module on your layout that generates sensor messages, but other than that it doesn’t matter. A value of “10” is offered as a starting point by our PC program Locoanalyse. If this value doesn’t conflict with anything else, use that value. If two BD4 units are connected to the SIGM20, it will generate sensor messages for 8 attached inputs to that board. Using the "On Board Inputs" field on the main SIGTM20 screen, you can choose the inputs to be "senors 1-8" or "sensors 9-16". This chooses whether the board generates messages with input numbers 1-8 or 9-16. Again, it doesn't matter which you choose as long as it is unique.

Program the board, then open the "message display" window on the  "LocoNet debug" menu tab. Add a locomotive to the track attached to a BD4 input; you should see a sensor message "on" generated. Remove the locomotive: you should see a message "off" generated. If you set board number "10" and input "1-8" you should see a message like OPC_SENSORREP sensor report:10,1 On"

Any device on LocoNet can see those messages and respond to them, including the SIGM20.

2. Responding to those sensors

Suppose BD4 input 1 is connected to track just after signal 1. you will want signal 1 to go red. 

  • Open the signal 1 edit screen 
  • Click "define" for "block is occupied when"
  • You see a list of 3 conditions that would make the signal go red
  • Highlight the first one (it normally is highlighted as you open the screen)
  • Choose "device type" to be "sensor" and select "10,1 occupied"
  • click OK. The signal condition will now be programmed to make the first BD4 input make signal 1 go red.

Follow similar steps for the other signals and sensor inputs.