DC Compatible Decoders

[DiveController]

I understood from reading threads on the site that decoders still allowed operation on DC.

On previous threads the owner of a misbehaving DCC equipped loco would be asked if it functioned on DC as a starting point to troubleshoot the decoder problem.

Turns out that TCS decoders do not function under DC control.

Does any one know what decoders are or are not compatible with DC running? …. and why?

Thanks in advance.

[Noel]

I thought the TCS decoders I used had a DC function once enabled in CV29. Will double check later in case I'm getting mixed up. I've been mucking around with so many different decoders these past few months a bit of 'doughalitis' may have set in. Noel

[Tarabuses]

My TCS decoders definitely allow DC control by adjusting cv29.

[DiveController]

I thought the TCS decoders I used had a DC function once enabled in CV29. Will double check later in case I'm getting mixed up. I've been mucking around with so many different decoders these past few months a bit of 'doughalitis' may have set in. Noel

Thanks very much, Noel. Remember the decoder is small in your hands and not far away

 

My TCS decoders definitely allow DC control by adjusting cv29.

 

I wonder if the previous owner did not have CV29 enabled and I'm not set up on DCC to change it yet…..

[irishthump]

I think pretty much all decoders now are set up to enable DC running, even the bog standard Hornby ones have that feature.

 

Also, when they say to check a loco on DC they mean to remove the decoder and run it on a DC track or power supply just to make sure the motor mechanism isn't the cause of any problems.

[DiveController]

Hi IT,

You may be right and the TCS decoder may have that function but presently I cannot reprogram CV29 and cannot check:facepalm:

If it was DC compatible I wonder why to would have been turned off or why it would come with CV29 set to non-DC running as default

The decoder is in a DMU with a function decoder in the dummy car. Neither works. They're hardwired, I think, so not easy to remove. Maybe it really just isn't just compatible? I'll try to check the TCS website again. Seller says it's not DC compatible and I think he's on the level

[DiveController]

Turns out that TCS decoders do not function under DC control.

Does any one know what decoders are or are not compatible with DC running? …. and why?

As a follow-up to the thread my new 2700 class DMU with its TCS decoder is now working perfectly. When received, the locomotive's TCS decoder had a long address of 2700 and would not work on DC. I reprogrammed the decoder to a short address (CV1) and it immediately ran perfectly on DCC and the TCS function only decoder in the dummy car worked the directional marker lights in that car flawlessly. When switched back to DC the DMU again ran perfectly when it would previously not do so, confirming what several members had stated, that their TCS decoders would allow the chipped loco to run on DC.

 

I don't have a manual for the TCS decoder but referred to my Lenz 21+ booklet. CV29 Bit 3 (which facilitates running on both DC and DCC (when enabled), versus operation on DCC only) is set by default to "1" (on), which allow DCC and DC operations.

 

I did not reprogram CV29, merely reset the decoder to a short address (CV1), so it appears that the CV29 Bit 3 was automatically reset to on.

 

It is unclear whether the CV29 Bit 3 was accidentally turned off ("0") by the previous owner disabling DC running, or whether programming an extended address alone (CV29 Bit 6) disables DC running by turning Bit 3 'off'.

 

I believe the TCS decoder in the dummy car is a function only decoder (without a motor control) and since both were likely programmed together as a consist disabling CV29 Bit 3 not only prevents motor operations but entirely disables operation under DC including functions (in this case, lighting)

 

Everything working correctly now, so happy this was such an easy fix!

Edited June 29, 2015 by DiveController