Uit de handleiding van de 76200:
"
Connection of special functionsInstead of lamps for lighting other devices such as smoke generator, telex coupling can be connected to
the light outputs.
For travel direction independent switching the outputs can be paralleled.
Note: If the driving direction of the locomotive does not agree with the indicator of your digital center, you
can reverse it by changing bit 0 of CV 29.
Additional special functions such as smoke generator, telex coupling or driver compartment lighting can be
connected to the special function outputs A1 and A2. The feed to the device is soldered directly to the
decoder circuit board.
The return line is connected either to the black wire of the decoder or the locomotive
chassis."
Lijkt me duidelijk waar die zwarte draad voor bedoeld is