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4digit DCC address problem


matt1471

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I'm using a Digitrax DCC control system and was trying to re-address a Zimo MX644D decoder which I have reset using CV8 etc.  I have re-address it correctly, and it recalls it's 4digit address when I read back from the decoder, however when placed on the main track to run, nothing happens, however it DOES work on the 2 digit address (03).

 

Any ideas?

 

Thanks in advance

Matt

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When the loco is using a 4-digit address (extended addressing) CV 29 bit 5 should be set to 1.  What's the value of CV 29 in this loco, and did you set the loco's 4-digit address just using the Digitrax (which should have set CV 29 automatically), or manually enter values for CVs 17 and 18?

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When the loco is using a 4-digit address (extended addressing) CV 29 bit 5 should be set to 1.  What's the value of CV 29 in this loco, and did you set the loco's 4-digit address just using the Digitrax (which should have set CV 29 automatically), or manually enter values for CVs 17 and 18?

 

I've had a look at CV29 and it reads back with a value of 'd010', which I presume to be 10.  I am unsure how I look/change bit 5 to 1?! 

 

 

If you are using a DT4xx throttle, whn you press enter to set the 4-digit address, the throttle asks for a confirmation, to which you are expected to press the + symbol to represent 'y'. Is this happening??

 

I'm using the Digitrax Zephyr DCS51 control station.  I'm 100% sure I'm programming the address correctly and can confirm that when I read back the address for both 2 digit and 4 digit, it confirms the address set, but I get no response from the 4 digit addresses.

 

 

 

Could anyone explain the process to change the CV bits on a Zephyr?

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I've had a look at CV29 and it reads back with a value of 'd010', which I presume to be 10.  I am unsure how I look/change bit 5 to 1?! 

 

 

 

I'm using the Digitrax Zephyr DCS51 control station.  I'm 100% sure I'm programming the address correctly and can confirm that when I read back the address for both 2 digit and 4 digit, it confirms the address set, but I get no response from the 4 digit addresses.

 

 

 

Could anyone explain the process to change the CV bits on a Zephyr?

 

The value of 10 for CV29 is for a two digit address, so for whatever reason, the decoder didn't respond and change the CV29 value at the same time as accepting the four digit address values.

 

 

You need to calculate the value for CV29, then enter it. There isn't any direct support for bit-by-bit entry. CV29 calculation is either through table in the Zephyr manual, or the handy calculators that abound - one I wrote is at

 

http://www.2mm.org.uk/articles/cv29%20calculator.htm

 

You probably want a value of 34 or 38 if wanting DC running.  (You don't want RailCom turned on, because out of the box, and without several third party extras, you can't get RailCom on Digitrax hardware)

 

 

 

- Nigel

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matt1471, on 05 Jan 2016 - 18:49, said:

I've had a look at CV29 and it reads back with a value of 'd010', which I presume to be 10.  I am unsure how I look/change bit 5 to 1?! 

 

If 'd010' means CV 29 has a value of 2 (indicating 28/128 speed steps) then you need to add 32 to it to signify extended addressing, so try setting it to 34.

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If 'd010' means CV 29 has a value of 2 (indicating 28/128 speed steps) then you need to add 32 to it to signify extended addressing, so try setting it to 34.

No. "d010" means ten, indicating 28/128 speed steps, plus RailCom.

What the "d" stands for is questionable - "Digital number" might be likely to match some aspects of the DT300/400/402 throttles from Digitrax.

 

- Nigel (Zephyr owner....)

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What's the address? Different systems handle addresses between 100 and 128 in different ways, some systems regard them as 2 digit addresses and some as four digit

 

3725 in this case.  Zimo state the decoder will take an address from 0 - 9999.

 

 

If 'd010' means CV 29 has a value of 2 (indicating 28/128 speed steps) then you need to add 32 to it to signify extended addressing, so try setting it to 34.

 

This is the black science of DCC that I just don't understand!! lol  Will give it a go and let you know!! 

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No. "d010" means ten, indicating 28/128 speed steps, plus RailCom.

Actually it indicates 28 rather than 14 speed steps.

 

[Edit]Being a Digitrax decoder this would presumably be transponding, not Railcom, and having it set could well be what is desired. Confused the system and decoder type.

 

Use of 128 speed steps is entirely at the discretion of the command station and independent of whether the decoder is set for 14 or 28 steps.

 

What the "d" stands for is questionable - "Digital number" might be likely to match some aspects of the DT300/400/402 throttles from Digitrax.

 

Decimal!

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These are the values that make up CV 29

 

1 - direction is reversed

2 - 28/128 speed steps instead of 14/27

4 - loco runs on both DC and DCC

8 - Railcom transmission enabled

16 - User-defined speed curve is used

32 - decoder uses extended address from CVs 17/18

 

To compute CV 29, add up the values for all the options you want from the above. Eg 28/128 speed steps (2) and extended addressing (32) gives a value of 34. If you want the loco to also run on DC (4) then the value would be 38. The remaining 2 bits (64 and 128) are not used for anything at present.

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