Decoder function problems : LUSENET : Wiring for DCC : One Thread

I am trying to use a four function Lenz LF100XF decoder to turn lights on and off in passenger cars. My command station is made by NCE and the cab is NCE also. After programing the decoder the lights may be turned on or off from the cab. But, when the car momentary looses power (voltage gliches over a switch, etc) I must reselect the car and turn the lights on again only to have the lights go off at the next glich. The problem also occurs when using NCE decoders for the same application. How do I correct this or what am I doing wrong? Thank you. Dave T

-- David Thompson (, October 10, 2003


Sounds like you are using one set of wheels for power pickup for the lights - try using more than one truck for power pickup and see if that helps.


-- Charles Lewis (, October 11, 2003.

The problem occurs when power from the rails is interrupted due to poor electrical pick up, causing the decoder to re-start, and the fact that the command station does not keep sending the 'turn on the lights' command.

If you don't have a huge list of operating decoders, you can set-up the NCE command station to continuously send out the last command to each decoder. Look for this in the manual. If you are controlling a big address list, this can slow down throttle rdesponses.

2nd option is to add a latching relay to the car(s). Let the decoder control the relay, with contacts wired to switch rail power to the lights. Use one decoder function to SET the relay to turn the lights ON. Use a 2nd function to RESET the relay to turn the lights OFF. Use momentary decoder functions to avoid telling the relay to do both.


-- Don Vollrath (, October 13, 2003.

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