Running MTH Powered units back to back DCS and Conventionally

Not that I've seen. Proto-2 engines don't seem to retain their MU configuration when started up conventionally. However, the old Proto-1 engines had a reset feature (#50) that you'd execute while the engine was running which would lock it in the direction it was travelling (#53 unlocked it as I recall). There might be a whistle/bell combination for Proto-2 engines that duplicates that function, but I haven't really investigated it since we run DCS.

To lock the direction of a ProtoSounds-2 engine the procedure is this:

1.  Run the engine at as slow a speed as possible (so it doesn't stall) in the direction you wish to keep the engine running after you lock it;

2.  On your MTH controller (Z-500, Z-750, Z-1000, or Z-4000) quickly tap the horn button once, followed by three taps of the bell button.

If the direction lock takes you'll get two horn blasts from the engine.  Sometimes when you tap the horn button the horn will sound.  If that happens try again.  This may take several tries to get it to work (I know from experience).

Also remember that when an engine has its direction locked there is no neutral.  When track power is on the engine will run in the direction it is locked, so any accessories, such as operating tracks or uncouplers, will have to be powered from an alternate power source instead of track power.

I hope that this is helpful to you.

Stuart

Thanks guys, was afraid of that. As one is a Proto 3 engine and the other Proto 2, can it be done for both so that one engine is always forward and the other one always reverse as it would keep them in sync. (And is it easily undone?)

Like the look of back to back modern units but may have to run them nose to tail then since reversing the motor wires for a few hours of running at a friends house and returning them to normal would be a lot of work

On the second-generation Proto-1 units, you could reverse the lighting and motor plugs on the board so the locomotive would cycle neutral-before-backward instead of the standard neutral-before-forward.

With Proto-2 engines (or the reset 50 on Proto-1) the direction is locked until you un-set it. Fine for mainline running, but not for switching or yard operation.

Under DCS, Proto-3 and Proto-2 engines peacefully co-exist when MU'd together (aka L@$#-Up) and the pair (or however many) operate as a single locomotive would with the lead and tail units lighting accordingly.

Lima;

I checked Barry's book and did a quick test on my DCS.

I believe the best way to get what you want is to open the engine and swap the wiring around. On some engines You an just unplug and swap plugs for the couplers but I suspect the lights and motors are going to be  more difficult.

This is somewhat permanent but will make the engine act as you desire in all modes without MUing them up. Just Remember which one faces backwards.