# PIKO 36125 Decoder Setup Issue



## cskozlowski (Dec 29, 2019)

Using a PIKO 36125 decoder in a PIKO DR-64 (2-6-2) locomotive and I am trying to change the default locomotive address of my train. I have tried to change the default DCC base address (CV1) from '03' to '64' using my Digitrax system (DCS-100 command station) and the digital decoder 'loses its mind' whenever I program a '64' into CV1. 'Losing its mind' includes running randomly and powering on at full speed and the function buttons all become rather random/non-functioning. I performed a factory reset (CV8) and it restored the base address (CV1) to '03' successfully. Any hints on what I am doing incorrectly would be much appreciated. I am using a 'program track' and not programming on the main. As an additional point of reference, I was able to change CV1 to '10' and that worked successfully.


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## Greg Elmassian (Jan 3, 2008)

Ouch...

CV1 is base address using short addressing...
CV2 is start voltage... 

You should re-study the standard NMRA CV's



https://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-9.2.2_decoder_cvs_2012.07.pdf



Greg


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## cskozlowski (Dec 29, 2019)

My original post was incorrect. It should say 'CV1', not 'CV2' (I have corrected the original post). I still have the issue as outlined.


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## Greg Elmassian (Jan 3, 2008)

What is your CV29?

I hope you are doing this in "service mode" (on the programming track in programming mode, not POM).

Greg


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## cskozlowski (Dec 29, 2019)

Yes, I am on the programming track in programming mode. Like I said, I was able to change CV1 to a '10', but when it is changed to an '64', it takes the value but then the train doesn't behave properly on the main (functions don't work and other 'bad' behavior). My CV29 is: '014' (decimal)


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## Greg Elmassian (Jan 3, 2008)

please answer question on CV29


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## cskozlowski (Dec 29, 2019)

CV29 is 14 (decimal).


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## Greg Elmassian (Jan 3, 2008)

change to 2, and try it (no reason for railcom, and turn off DC mode for now)...

Noise on the tracks can have issues with DC mode...

Greg


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## cskozlowski (Dec 29, 2019)

Will do later today and report back. Thanks Greg. After I change CV29, will then attempt the change to CV1.


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## Greg Elmassian (Jan 3, 2008)

Also to be sure, read back the values to be sure they "took" (I think you are already doing this), and be sure you have the throttle/cab set to 28/128 speed steps, not 14... this could be a problem...


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## cskozlowski (Dec 29, 2019)

So, interesting results. I changed CV29 to '2' and did a readback to confirm the setting took (I am in 'direct mode' on my digitrax system when I program CVs on the programming track). I then changed CV1 to a set of different address (10,20,30,40,50,60,61,62,63 and 64) and read back the values. I put the train on the main after each time and got some very interesting results, these values worked (10,20,30,40,60,61,62,63) with the exception of 64. Kind of fascinating results. When CV1 is programmed to 64, the train will be 'full speed' in 'reverse' direction when DCC power is applied - I am on test rollers so the train isn't going anywhere. So I did some thinking: 64 (decimal) is 40 (hex) so I am now wondering about the valid address space on a PIKO decoder (36125) in the short address space (looks like it might only be 6 bits instead of 8 bits which is quite strange). It is supposed to support values up to 127 on CV1. I was going to set the address to 65 (decimal) and see what happens. The good news is that it looks like addresses up to 63 work just fine - my train is a model BR64 so I was hoping to use 64 as the locomotive address but we don't always get what we want.


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## cskozlowski (Dec 29, 2019)

Just an additional random thought when CV1 is set to 64 (decimal): IF there is a 6 bit limitation in the address space of CV1 on the PIKO decoder (36125). The train running 'full speed' actually makes sense since the CV1 lower 6 bits wouild be all ZEROs which is interpreted by the decoder as running in DC mode, since the rail voltage in DCC is always 'maximum' with an embedded PCM signal this would result in the locomotive running at 'full speed' on the track.


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## Greg Elmassian (Jan 3, 2008)

Very weird, but often rolling stock manufacturers negotiate a "deal" for a crippled or older model of decoder to keep the price down, been doing this for year in all scales.

What is the MFG id and version? (CV 's 7 and 8).

Some DCC systems are also limited in sending commands, but not your Digitrax. Gotta be the decoder.

Greg


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## cskozlowski (Dec 29, 2019)

CV7: 37, CV8: 162. I am thinking of getting the soundtraxx decoder (which I have used on another locomotive) for this locomotive but they are currently out of stock because of chip shortages. Thanks for all of your help Greg, the experimentation I did this afternoon really helped to nail down the issue.


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## Greg Elmassian (Jan 3, 2008)

Yeah, really sounds not too cool, should be no issues with that address. Be careful on the soundtraxx, they can be sensitive to voltages over 19v DCC... I run the full spec 24v and the Tsunami's go nuts...

Greg


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## Dan Pierce (Jan 2, 2008)

Some manufacturers do have a CV1 address that can not be used, Lenz did not like address 99 if I remember corectly, and Zimo did not like address 1 and 2.


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## cskozlowski (Dec 29, 2019)

Based on my testing, the PIKO decoder (36125) setting CV1 to 64 is a bad idea.


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