TCS M1 decoder behavior

[Scott Lupia]

Guys, I installed a TCS M1 decoder in my GHB L1 mikado replacing a Digitrax DZ125 that was working fine.  The behavior I am seeing is movement of the engine with no relationship to speed tables.  Sometimes it starts around speed step 14,15,16, it will stop at random speed steps in the 20's and start going again.  It does the same in reverse although a little better.  I checked wiring and connectors to see if there was a breakage in motor voltage and it is constant.  I tried altering the speed steps individually and that had no effect.  It is as if certain speed steps don't exist and will not take values.  When I put the engine on the programming track (I am using a NCE Powercab version 1.28a) and select "use alternate speed table" the behavior is worse than if I leave it on "use standard speed table".  I just ordered the upgrade chip from NCE to version 1.65 fro my 1.28a.  I was thinking that maybe the out of date software could be the culprit.  Has anyone ever seen this behavior from a TCS decoder before?  Worse case scenario, I will just put the Digitrax DZ125 back in because that worked fine.

Scott Lupia

[peteski]

If the Digitrax decoder works with the PowerCab then it is not the cab.  The DCC packets transmitted over the track (containing info such as direction and speed steps) are the same coming from the cab, regardless of the decoder used (they adhere to NMRA specs).  One thing you should check is if both the decoder and command station are set for the same number of speed steps (it is either 14 or 28/128).

How does the decoder behave without selecting any speed tables and with Vmin, Vmid, and Vmax not set (default setting with no custom speed curve)?

I have a strangely behaving TCS Z3 decoder, but I haven't been able to play around with it much.

[Scott Lupia]

Peteski,
The decoder misbehaves on factory settings. I did a factory reset and had the same result. What has me puzzled is the erratic behavior which seems to have no rhyme or reason. I hate the idea of trying another decoder in there because each time I do something major the L1 gets a little rougher around the edges. I was considering another TCS decoder just to see if the problem lives within that particular decoder. I did check to make sure we are on 28 speed steps and it is.

Scott

[Burlington Bob]

I would suspect that the decoder is at fault and if it's under warranty I would contact TCS.  I sure wouldn't give up on TCS decoders, I think they're the best available in their price range.

[Scott Lupia]

Well, I got a second TCS M1 decoder and it behaves the same way as the original one.  I did upgrade the Powercab to version 2.65 and that did not help.  I am currently waiting for a response from NCE since the issues seems to be with the NCE powercab and not the decoders.  I have no idea why my Powercab would not work with TCS decoders. 

Scott

[peteski]

Well, I got a second TCS M1 decoder and it behaves the same way as the original one.  I did upgrade the Powercab to version 2.65 and that did not help.  I am currently waiting for a response from NCE since the issues seems to be with the NCE powercab and not the decoders.  I have no idea why my Powercab would not work with TCS decoders. 

Scott

I'll be curious as to what you find out. Personally I doubt it is the NCE system (but it will be good to eliminate that possibility).  I tried my misbehaving NCE Z3 decoder on a CVP EasyDCC system and it was still acting strange as far as speed steps are concerned.  but then again, my problem might not be the same as yours.

[Scott Lupia]

Peteski, I am going to give the decoder a shot on my friends NCE Procab system. It's either going to work, or not. I will learn something either way.

Scott

[peteski]

Agreed. Also, if you had another friend with a different brand DCC system that would be even a better test.

[carlso]

Scott - if you had a DZ125 that worked fine, then why did you want the TCS. What did you hope to gain?

Anybody else - I have a KATO Mike that had a TCS M1 that literally melted the tender floor. Do not know why as I did not install the M1. I was thinking about a DZ126 install. I have also thought about the Zimo 621, which I have in another loco that is one of my best running. Any thoughts from you on which one?

Carl

[Mike C]

Scott - if you had a DZ125 that worked fine, then why did you want the TCS. What did you hope to gain?

Anybody else - I have a KATO Mike that had a TCS M1 that literally melted the tender floor. Do not know why as I did not install the M1. I was thinking about a DZ126 install. I have also thought about the Zimo 621, which I have in another loco that is one of my best running. Any thoughts from you on which one?

Carl

I've got a DZ 125 or 126 in my Kato 2-8-2 .  Runs great .  The only thing is the top speed is way to high . But after adjusting cv 5 and 6 it will be much better.

[Scott Lupia]

I have seen TCS decoders run well. I think they can give better slow speed control. The M1's I did install (when they sort of worked) were quieter and smoother than the DZ125. The DZ125 is a good decoder and I won't be upset if I have to stay with it. I would just prefer the M1.

For what's it worth, I toyed around with the M1 more today. I turned the BEMF off and adjusted the dither functions (CV 55, 56 and 57).  I got better control, got the engine to run at speed step 1 and z consistent speed table. I just couldn't get it to start consistently at speed step 1.  I am getting the feeling that the root cause is CV settings.

Scott