
There are a various way to control the signalling on a layout. One possibility is to use the same P and N (rails) to have it fully integration inside the DCC addressing. For this option and using ROCO devices, the layout and material needed is:
- Z21 Central station
- ROCO 10836 Switch Decoder
- Traffic light or LED

It is compulsory to connect P and DCC from the Z21 Central Station to ROCO10836. The user manual says it is not necessary, but this is NOT correct. By default, the ROCO 10836 Switch Decoder creates a pulse. This does not work for lights as they need to have a constant value. This can be configured in the CV list of the switch decoder by configuration
- CV 41 (Operating mode output 1) = 4 : Bi-stable continuous operation, either output A or output B active.
- CV 4N(Operating mode output N) = 4 : Bi-stable continuous operation, either output A or output B active.
To revert to switch controlling operation, set the CV with value of 0
