DCS Signal

Hi ps 2 3volt engines much have the red wire on the center rail from the transformer and the black wire must be on the outer rail ps 3 does not matter and will work either way ps 2 3 or 5 volt will NOT work unless above as mentioned! Alan

also, ps 2 3- and 5-volt engines should start up in conventional if dcs in tiu is turned off!

The locomotives start up and run fine on my test track which my TIU connected to. I tried reversing the lines on my layout to see if I messed up with that.  Did you mean to tell me that there's some other electrical/electronic thing going on.

Agreed, while you said you swapped wires, a classic symptom is if PS3 engines can work on a track, and PS2 doesn't, we generally suspect polarity. https://ogrforum.com/...4#177398552057085634

That said, you also mentioned 15 year old engines. Point being, that in order to save the DCS address in the engine from "add engine" command it REQUIRES a working battery subsystem. Again, cannot stress this enough- MTH DCS doesn't actually save the new address into the engine firmware until the engine performs a complete shutdown (loss of track power- AND the battery or super capacitor powering the microcontroller) in the engine through the shudown sequence to save that new address.

I'm saying this, because if you attempt to add the engine while on you main track, and it adds and increments a new ID- huge flag your battery subsystem is not working. Yes, the normal test is does the engine continue to play sounds when track power is dropped, but further proof of that test is saving an updated ID or settings to memory.

Again, let's say you added the engine on the test track. In order to move it to the mainline, it lost power. If the new ID didn't save in the engine because the battery subsystem is not up to par- then it reverts to an old ID however your remote stored the new ID. So now you have an ID mismatch and get engine not on track when pressing startup.

If you then re-add the engine, it now increments (duplicate names in the remote) and as long as you do not lose track power it keeps responding to that ID current just added ID- however, if power is lost, then you have to re-add it.

A clear symptom of needing to replace or at least check on the battery and the system as a whole.

Ok thank you. I have spare BRDs to replace the battery with on the 4-4-0 and the BRD I replaced about three years ago on the 2-8-0. So that would be my next step.  I'm a little concerned that this has happened at the same time and if there is some other issue I missed.

I should add that I've had these locomotives for many years and I'm not trying to add them.  If I have to delete and re add them so be it.

@Richard Guitar 013017 posted:

I should add that I've had these locomotives for many years and I'm not trying to add them.  If I have to delete and re add them so be it.

Well, we are back at- signal basics. If you think and know the ID conflict scenario is not it- just it works on the test or side track, your mainline only works with PS3, that generally points at polarity being the issue. Otherwise, the other answer is your signal is just weak and on the verge and PS3 gets better signal than PS2.

@Alan Mancus posted:

Hi ps 2 3volt engines much have the red wire on the center rail from the transformer and the black wire must be on the outer rail ps 3 does not matter and will work either way ps 2 3 or 5 volt will NOT work unless above as mentioned! Alan

also, ps 2 3- and 5-volt engines should start up in conventional if dcs in tiu is turned off!

THANKS for THIS POST Alan.   

As long as I've poured over info on the forum THIS info on polarity is new to me...........  I always thought the the RED wire HAD to be on the CENTER RAIL no matter what  engine was present. 

Thank you Vernon.  Before I replace/install new BDRs, is there a way I can boost the signal?

@Richard Guitar 013017 posted:

Thank you Vernon.  Before I replace/install new BDRs, is there a way I can boost the signal?

No, not really. DCS signal is rather complex since it is put into the power via the TIU internal circuitry so there is no "booster". Further TIU channels can get damaged over time by voltage spikes and other events that kill off sections of the signal driver chip. Again sort of 2 problems- DCS is bi -directional so your engines only have a fixed transmit strength back to the TIU and no way of boosting that, and further, TIUs and specific channels of the TIU can take hits over time that begin to degrade the (TIU to engine) transmit strength.

The classic troubleshooting with no other tools or equipment is just connect a different channel of the TIU to your given problem track. If the problem follows the TIU channel- then there might be something up with that channel of the TIU.

Massive multi-page topic on DCS signal and TIU signal generator section repair, protection,  and discussion.

https://ogrforum.com/...between-aghr-and-mth