Ok, I know the 128 speed is not a CV29 value and that it is the control station not the decoder that sends the 128 speed option to the decoder but WHY?
It is very frustrating to begin a train moving then you remember it needs to be set to 128 speed. Tou either stop the train or if you try to select 128 on your controller it stops until you add throttle.
Is there some reason this can’t be an option on the locomotive decoder? If it can, has anyone done it?
Gary
What DCC system are you using that yo need to set speed steps for each train?
At my club using Digitrax DSC-200 (and DCS-100 before that), the OpSw's are set to always use 128 steps.
Peter
woodoneOH, but CV29 does have a value for setting speed steps. Bit 2 in most cases. Who’s decoder are you working with?
I have LocSound, TCS, BLI and Bachmann But the question was a general one.
CNR378 What DCC system are you using that yo need to set speed steps for each train? At my club using Digitrax DSC-200 (and DCS-100 before that), the OpSw's are set to always use 128 steps. Peter
I’m using NCE Procab system. The system maintains the information until I remove the locomotive from the layout. If I want to use it at a later time an place it back on the layout I need to reprogram the 128.
If you use JMRI for programming, there are 28 speed steps.
And some people don't like using 128 speed steps, I being one of them. I belong to a club where many have DCC equipped locos. And many don't adjust the locos to start moving at speed step one. Very frustrating to me to have to get up to speed step 40 or 50 (of 128) before the loco moves. I can get starts just as smooth with 28 speed steps by slowly advancing the speed controller and observing what the engine is doing.
There doesn;t need to be a setting in the decoder because the decoder automatically can figure it out based on the control packets it is receiving. There's no need for any option on the decoder, what would that buy you? If the system sends 28, the decoder responds properly. If the system sends 1128, the decoder responds properly. Having a setting would make things even more confusing if you send 28 and it's set for 128 or vice-versa, and the loco doesn't move.
I still can't believe there is not a setting to make NCE default to 128. Time and time again it is shown that (especially slow speed) response is significantly better on 128. You should be able to make the global default anything you want. Digitrax defaults to 128 but you can configure the default to be 28 or 14 if you want.
--Randy
Modeling the Reading Railroad in the 1950's
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rrinker There doesn;t need to be a setting in the decoder because the decoder automatically can figure it out based on the control packets it is receiving. There's no need for any option on the decoder, what would that buy you? If the system sends 28, the decoder responds properly. If the system sends 1128, the decoder responds properly. Having a setting would make things even more confusing if you send 28 and it's set for 128 or vice-versa, and the loco doesn't move. I still can't believe there is not a setting to make NCE default to 128. Time and time again it is shown that (especially slow speed) response is significantly better on 128. You should be able to make the global default anything you want. Digitrax defaults to 128 but you can configure the default to be 28 or 14 if you want. --Randy
I’m guessing you already talked to NCE. I like the 128 setting because I get really good low speed control and it smoothes out that jerking you get with some locos.
gdelmoro I’m guessing you already talked to NCE. I like the 128 setting because I get really good low speed control and it smoothes out that jerking you get with some locos.
It isn't the speed step setting that makes any one internal drive smooth...it's the BEMF sensitivity and how you configure your decoders to manage and to respond to BEMF from the motor. This has been true of modern decoders since about 2006 or so.
The fewer speed steps there are, the more 'discrete' the variance between the speed at which the drive propels the locomotive from step-to-step. When you add more steps, they are less discrete. Using more steps means, simply, that the difference in speed is less...less discrete...as you add each step to your setting. It won't necessarily make your locomotive move more 'smoothly'.
It all comes down to if you have a voltage range from 0-12V and control it with 128 steps, each step is a finer change thant if you divided the same range into 28 steps.
Some recent MR reviews of DCC locos show this - they tested the loco on both 28 and 128 steps and you cna see how, with no adjustments whatsoever, a loco might start at 3 SMPH on step 1 out of 128, but control the same loco with no adjustments with 128 steps and at step 1 it runs at less than 1 SMPH.
My old Atlas Commander I had years ago would always default back to 28 steps every time it was turned on. Had to manually reset it to 128 steps every time it was turned on.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Go here and scroll down to page 34. The chart there shows what CV29 should be set for 128-speed steps.
OK so I called NCE and they tell me the easiest thing to do is when I power up the DCC System just select 128 on the controller. From that point any locomotive on the layout or placed on the layout will be in 128 speed as long as the decoder supports that and the proper CV29 value is entered.
gdelmoro .. as long as the decoder supports that and the proper CV29 value is entered.
.. as long as the decoder supports that and the proper CV29 value is entered.
This is key. The system may need to be configured to do 128 speed steps, not sure, but the decoder needs to have CV29 programmed with the right value. The value will also include lighting parameters, which way the locomotive should move in reverse, etc, so you have to refer to a table or a calculator and remember all the characteristics you want before you select the right number and enter it.
Right - but that value for CV29 is the SAME value used for 28 steps. So if you forget to press the 128 button, the loco will still operate. There's no way to set a decoder for 128 steps only.