Starting two engines with DCC

QUOTE (Robert Stokes @ 30 May 2008, 09:31) <{POST_SNAPBACK}>Although I bought my Bachmann EZ DCC controller last year, I have only just got round to fitting decoders in three locmotives and started operating it.

One thing gave me cause for concern straight away. Suppose I press number 7 to start an express train and wind the control knob up to a fairly high speed. If I now press button 2 to start some shunting, the engine in the goods yard starts to accelerate and I have to frantically wind down the control knob. Of course, I can't wind down the control knob before pressing number 2 or the express will slow down.

The only way round this that I have discovered is to press 10 (for a non-DCC engine which I shall not have on the layout) turn the control knob all the way down and then press 2. I can then start the shunter very slowly.

Does this happen with all DCC systems? Have I got it right and there is no simpler way of doing it? Thanks, Robert.

Hornby Elite has 2 control knobs but even so you can re-select a second loco on any knob and run the new loco up from a standstill. Mind you the Elite knob is rate dependant and has no Min-Max setting - that is it goes round and round forever either way.
Robbie

QUOTE (Robert Stokes @ 30 May 2008, 17:31) <{POST_SNAPBACK}>Although I bought my Bachmann EZ DCC controller last year, I have only just got round to fitting decoders in three locmotives and started operating it.

One thing gave me cause for concern straight away. Suppose I press number 7 to start an express train and wind the control knob up to a fairly high speed. If I now press button 2 to start some shunting, the engine in the goods yard starts to accelerate and I have to frantically wind down the control knob. Of course, I can't wind down the control knob before pressing number 2 or the express will slow down.

The only way round this that I have discovered is to press 10 (for a non-DCC engine which I shall not have on the layout) turn the control knob all the way down and then press 2. I can then start the shunter very slowly.

Does this happen with all DCC systems? Have I got it right and there is no simpler way of doing it? Thanks, Robert.

***Robert, the EZ command is about the only controller that will give you this problem. The only practical answer is the one you are using really... or replace it with a more capable unit such as the NCE PowerCab etc...

Richard

I originally started DCC with a Hornby Select.

The problem was the same, in that if you had engine 1 running at full speed, and then selected engine 2 to run on half speed, returning to engine 1 caused it to go at the speed of the previous engine.
When changine engines, you had too try and remember what the setting was on the other engine, and try and quickly move the throttle to compensate.
It was this problem, and a few others, that caused me to ditch it.

I purchased a Prodigy Advanced 2, and have not looked back since.

The prodigy remembers the last throttle settings of all engines. When you select an engine, its last throttle speed is shown.
I think 'RAILSTIMULATOR' is confused, as Prodigy does not default to zero on selecting an engine. It may look like this, as normally you would have the throttle at zero when a train is stopped.
If you have a number of trains running, and you switch off the power, all trains obviously stop. If you then switch the power back on, nothing moves.
On selecting one of the engines, the controller will show what speed it was set at before switch off. A slight movement of the throttle will then send that train on its way at its original speed. Selecting the next train, and again a slight movement of the throttle will then restore all trains to their original speed.

I use the Lenz BM1 train control system, and all trains are set at their operational speed, and are controlled by signal lights. It is therefore imperative that the set speeds remain at all times when switching between trains.

AlanB

Actually, there are other controllers with the same problem as Robert describes. These are usually entry-level controllers. For example, I have an old Lenz Compact that suffers from that same problem of having fixed speeds for a given control knob position. I also have an NCE Cab 04P (the "P" stands for potentiometer) that does the same thing.

The standard NCE Power Cab / Pro Cab has a continuous wheel and buttons that have no fixed settings so "adapt" to whatever settings a locomotive was previously using when one toggles back to that locomotive. The Pro Cab stores up to six locomotives (the number is user-selectable) in memory slots and "remembers" each of their settings. The Power Cab only stores two trains at a time.

Neil S Wood has an ESU ECOS system and that gets over the problem by having motorised knobs, as well as having two of them! When another locomotive is recalled, the knob rotates under its own power to the previous setting for that locomotive (quite disconcerting, actually, until one gets used to it!!).

So, the simplified answer is: if you don't like the speed jump when recalling a different train while running a second (or third or fourth!) train, you will have to upgrade to a more sophisticated DCC controller and eitehr sell on your existing one or hook it up as a "slave" unit for occasional use or shunting.

Incidentally, the reason I have the Lenz Compact is that it was my "starter" unit while I experimented with DCC to see if it was the way I wanted to go. Needless to say, I was hooked! There is nothing wrong with staying with what you have, as long as it does what you want it to. I would guess that somewhere down the track (was that a pun? ) you will want to upgrade to the higher-end unit. By that time there may be a whole new range of sophisticated units on the market.

Enjoy what you have and worry about the future only when you are ready to.