Programming track booster

[BandO-55]

Our club is having a problem programming locomotives using a programming booster. We can change the CVs but all the CVs read back as 255 or 6383. The Digitrax DCS100 command station programming output is connected to a PTB-100 programming booster , through a 4PDT toggle switch to the programming track. We've had this configuration for a number of years without any problems.  I’ve tried several things to locate the problem: I connected a short section of track directly to the programming terminals of the command station. We were able to program and read back the CV values in a non-sound decoder. Next, I went back to our existing wiring, removed the programming booster and wired the command station directly to the toggle switch. Again, we were able to program and read back the CV values in a non-sound decoder. At this point I decided the programming booster was defective. A club member brought in a PTB-100 programming booster he was not using.  I wired it into the circuit replacing the old one. We tried programming another non-sound locomotive and received the same results: able to program but unable to read the CV values. When reading the decoder, the indicator LED on the programming booster would flash and the locomotive would slightly lurch forward, but the DT 402R  throttle being used for programming, would read 255 or 6383.  We tried more than one non-sound locomotive and more than one throttle with the same results.

 

Does anyone have any suggestions?

 

George 

[gmpullman]

Hello,

Are you certain the switch is good and the contacts are clean? 

I was never a fan of having a programming track that was a part of the layout trackage. I remember reading in the early days of DCC 'no-no' practice that the risk of bridging the usual DCC current/signal onto the programming track or vice-versa could be catastrophic. Some diagrams were made showing an isolation section of track to act as an insurance 'buffer' so that something as simple as one wheel bridging the gap would not scramble signals or destroy decoders.

Speaking of gaps, how good is the integrity of the gaps between the layout trackage and the part-time programming track. Even some scenery materials might compromise the insulated gap sort of forming a 'semi-conductor'.

Good Luck, Ed

[BandO-55]

If I remove the booster from the circuit, we can read and write to non-sound decoders (I haven’t tried sound decoders). I’m confused because I tried two different boosters with the same results. I find it hard to believe two boosters have failed exactly the same way.