Newbie question about switching between locos in DCC

[Gannet]

So today, for the first time, I had multiple trains running on my layout.  Yay!

But here's what I found disconcerting/annoying.  I'm using a Digitrax Zephyr Extra DCS51.  Let's say I had loco 1 running at the speed I want at throttle position 2, but loco 2 needs to be at position 3 to run the speed I want.  If I then toggle from loco 2 to loco 1, loco 1 immediately changes speed because the throttle is at position 3.  Not Good.

So is this inherent to DCC throttles?  Or perhaps (I hope) it's just an artifact of using an entry-level unit?  What I expected to happen is that I could toggle between locos and they would remain at their previous speed unless I moved the throttle.

I found this annoying to the point of being almost a deal breaker.  Do I need a different Digitrax throttle, a different system (NCE?), or what?

[Ho crazy]

 It's your system. I use mrc prodigy advance and don't have any problem with speed memory. I used to use a nce system a couple of years ago and had no problem with it also. I would guess the digitrax system you are using does not have memory for speed.

[cacole]

I've never used a Digitrax system, but with my NCE ProCab radio throttles I can select between six different locomotives in the recall stack and their speed doesn't change.

[Lake]

I use Digitrax, Super Empire Builder, but have a DT400R dual throttle and a UT4R throttle. Though I never run more then one engine at a time when doing operations by my self as my layout is point to point. With other people more engines are run.

There are many who use the Zephyr so one most likely will help you out. Many users on some of the other forums also.

[maxman]

Gannet

So today, for the first time, I had multiple trains running on my layout.  Yay!

But here's what I found disconcerting/annoying.  I'm using a Digitrax Zephyr Extra DCS51. 

Do I need a different Digitrax throttle, a different system (NCE?), or what?

What kind of controller (speed changing device) does the Zepher have?  Is it a potentiometer type with stops on each end, or does it have an encoder (like on your car radio volume knob)?  If it has a pot, it won't do what you want.  You will have to get an add-on controller.

[Stevert]

Gannet

So is this inherent to DCC throttles?

  It's inherent to DCC throttles that use a potentiometer as opposed to an encoder.  If you got an NCE system and used one of their CABxxP throttles, I'm pretty sure you'd run into the same issue.

  You can avoid the issue on your Zephyr by using either another Digitrax throttle or a jump throttle for the 2nd loco. 

  Or better still, you can speed-match your locos so they all run at the same speed for a given throttle setting.

[selector]

To be clear and specific, I use the old DT400 throttles with the twin encoders.  Like the older DT400, the modern duplex ones are also supplied with two encoder knobs that rotate.  They chirp with each rise in speed step if you like that feature, or are silent...your choice of settings.   You can dial up locomotives at will, adjust speed, and none of them will jump as soon as they are acquired.  If you can fit a DT400 variant to your Zephyr, you are sure to be glad you did ere long.  For me, the DT400, NMRA track gauges, Opti-Visor, sound decoders, and RTR steamers make the hobby for me.

Crandell

[CSX Robert]

As has been mentioned, upgrading to a DT402 throttle will eliminate that issue.  There are also a couple of things you can do to reduce the effect.   The first is to program some momentum into your locos.  They will still change to the current throttle setting when selected, but they will change gradually instead of jumping to the new speed.  The other thing that can help is adjusting the throttle between locos.   After  you press "LOCO" to select a new loco, but before you press "LOCO" again to finalize the selection, you can adjust the throttle setting to try to approximately match the next loco without affecting the previous one.

[Texas Zepher]

Gannet

If I then toggle from loco 2 to loco 1, loco 1 immediately changes speed because the throttle is at position 3.  Not Good.

I only usually run one throttle for each locomotive unless they are consisted together.   On a Zephyr there are two jumper ports where a regular DC throttle can be used for a DCC throttle.  I would use the built in Zephyr throttle for one locomotive and one of the jumpers (or buy another Digtirax throttle) to use for the second train.  That way there is no "toggling" between the locos.  One throttle is always in control of one train.

[Gannet]

Thanks all for the helpful replies.

[bbrown]

I also use a Zephyr for my layout.  When you press the LOCO button, the numbers are flashing on the display as you type in the next locomotive.  Before you confirm your numbers by pressing LOCO again, the instruction manual tells you to make sure the speed and direction knobs are in or near to the state of the running engine.  In other words, you could be selecting an engine running forward at 25% throttle, but your knobs are set on reverse and 50%.  As soon as you confirm the address selection, that decoder will respond to the position of those controls.  I too, use a DT400 that automatically select the current state before you select the decoder.

[rrinker]

 Yup, biggest downside of a potentiometer control, can;t switch between moving locos withotu the speed changing.  Only one system I know of can handle that, and that's ESU, because the potentiometers are motor drivin, so when you select a different loco, the knnob actually moves to the matchign speed setting. COmplicated (and typically German) way of doign what an encoder does naturally.

 The first purchase I added to my Zephyr was a DT400 and I haven't looked back. I don't mind running on the club layout with a UT4 (also potentometer based, and with the same problem) because I'm not switching between multiple runnign trains, I select one and it's always active until I'm done runnign it. But at home where I switch back and forth frequently, the encoder is MUCH better. Some don;t lie encoders because they perpetually turn,t here's no hard coded stop or full position, but it's not too difficult to see if your loco is goign faster or moving, you don't have to look at the throttle display to see the speed setting. I normally operate with my throttle down at my side, not lookign at the screen on it, and just rotate the knob with my thumb. And int he case of the DT400/402, you can click the knob like a mouse button to change direction. Completely one-handed operation, leaving the other hand free to uncouple or deal with car cards.

                                    --Randy