Re:Break on DC
Neil Robinson said:
I naively assume that all decoders with the brake on dc facility will [stop/pause/reverse with brake-on-DC]
I'd appreciate clarification of the above.
Pretty sure that's a specific Massoth/LGB "feature" to allow automation of a back-and-forth shuttle service without the need for external electronics, although I think some other decoders will try and "soften" the effect of quickly changing the DC polarity under analogue, which in some ways has the same effect as the feature you're describing. Very much depends on the decoder though.
Generally the "Brake-on-DC" function is as Colin described, ie. use it to slow a loco to a gentle stop in front of a red signal, and accelerate away again when DCC is re-instated to the rails. I've seen it used to great effect on an N gauge modular system, you just have to spend some time programing all locos to have reasonably similar deceleration characteristics so that they stop in the same distance. You can leave the acceleration rate different to suit the type of loco and train it's hauling.
Colin, yes indeed the "faux dc" on a DCC system is directional, otherwise you'd not be able to drive your analogue loco back and forth at will!
There are some decoders out there that are not great at running correctly under DC, which is why a lot of people turn off the "run on analogue" function in the decoder to avoid runaways if they're strictly a DCC only operator. I've got an older NCE decoder that sometimes seems unable to make it's mind up which way to run under DC, so that loco doesn't get taken to friend's lines! It runs perfectly on DCC.