If they are always going to be together, then just give them the same address and program the light functions accordingly. From experience get a TCS function decoder. The Digitrax one inexplicably does not have directional light effects.
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
It depends. What particular locomotives are you getting? Are we talking F-units?
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I will be getting an HO scale married pair electric Multiple unit set. Car A will be powered while car B will be the dummy. I will install a Digitrax SDH164D decoder in car A and a function only decoder in car B. I will also give an address to car B. Can regular Digitrax decoders be MUed with function only decoders? I plan on doing this so when car A is going forward the tail lights on car B will come on. Are there other ways of setting up this type operation?