Question regarding TMCC, Cab1 and my Dash 8.

Good afternoon,

We originally build our club network on the MTH DCS command system.

We then added some Lionel engines and we controled them via a black command base hooked to the MTH TIUs and a CAB-1 remote control with its pull out antenna

We then replaced this Lionel system with a Legacy base and remote.

We run our Lionel (and Weaver and 3rd rail, etc.) both with the Legacy remote and MTH DCS remotes.

We have now a fundamental question. We need to know what are the diffences or specifics between TMCC and CAB 1 as we see it as choices on the Legacy remote control.

Thank you very much.

You may answer me on the forum and/or my email address. 

The big difference is the CAB1 uses relative speed steps, the TMCC setting uses absolute speed steps.  The TMCC locomotives always had the capability of absolute speed steps, but the old TMCC system didn't have the capability.  You also get the throttle graph, the train brake, the keypad icons, etc.

Jeff,

In the early 2000's we used primarily Railsounds 4.0, there were some units that ran RS 3.0, but most were 4.0.

There were also 2 versions of the Dash-8 from 2002. The one shipped with TMCC was cab #580. The other was #582. Depending on which one you have you may have a "generic" diesel soundboard in the loco (the Towercom will tell the truth) which would not have the horn sequence at reset.

In regards to RPM's, the RPM's are initiated by the throttle, the serial data sends a command to the RS audio board to ramp up. The soundboard then looks for an input (specifically on pin 22 of the audio board) to confirm it is in fact moving and the RPM's stay ramped up. More throttle up on the red thumbwheel registers more RPM ramping, the pulse on pin 22 does not change, it is constant, so after the initial throttle up it looks soley at the serial input from the throttle turn on the remote. You can ramp up manually too, if you want more RPM's at slower speeds, but the throttle turns is what ultimately tells the sounds to ramp up or not, even after you have used the manual override keys (3 and 6).

It is quite possible the "duty" cycle wire from the DCDS is not sending that pulse to pin 22 of the audio board. Turn the throttle, get the loco moving, manually rev up to notch 3 then press and hold the brake button. If the brakes fail to squeal then it is the duty cycle lead that is the culprit. If the brakes do squeal, then there is no problem, aside from the fact the specific audio board in your loco does not feature the horn blast at AUX1 + 0.

Some RS 4 audio boards give you crewtalk when you turn smoke on and off, others do not. Some RS 4 boards will toot the horn at reset, others will not.

The auxiliary program code of "8" is correct for this loco.

Hope this helps clear up the confusion.

Mike

Will TMCC engines run better or worse when we select CAB 1 on the Legacy remote to run them?

And vice versa, running CAB 1 engines (or Legacy for that matter) with the TMCC program selected on the remote?

Thank you very much.

Jean-Paul.

One thing to consider when using both Legecy and the Original TMCC Command base, there is a slight delay involve, in that the TMCC command base is down stream from the Legecy base and all track commands to the engines go through the Legecy base. So if you are using a Cab1 handheld, it talks to the TMCC Command base, which in turn talks to the Legecy base and then to the engine.  We've noted this at several club meets where both systems were being used.  I believe this all in the best interest of backwards compatibility.

I have found that TMCC is better to run TMCC engines and try to stay away from cab1 mode.  legacy engines do not always respond in cab1 mode, but will run in TMCC mode.