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QUOTE (wiggy25 @ 15 Jun 2008, 13:03) <{POST_SNAPBACK}>Hope someone can help with this!

I have this CT elektronic decoder fitted to a diesel 04 shunter and it's being a swine!

It says that programming CV1 with a value of 0 gives it a hardreset.

So I did that first.

Set a short address to 7

Ran the loco all ok works fine, but very slow at top speed.
So I altered CV5 (Max speed top volts) to a value of 200, it says the range is 0-255.

I couldn't then run the loco as the address had changed to 200!

This seems to happen no matter what settings I put in, when ever I change any of the speed settings the address changes as well!
This decoder was replaced only a week ago, and I've only just got round to running it, now find it's playing up, is it another decoder required?


I've just been round all the same issues (in an Farish 04 with my own 2mm finescale wheels). After some headbanging, I now have a loco which goes from crawl (1 wheel turn in 12 seconds) to sensible top speed, sane acceleration etc.

There is a bug in one of the JMRI/DecoderPro files, so use caution if using those (see below).

In summary:

MUST use DIRECT MODE to program the chip, don't try anything else.

CV1 = 0 does execute a factory reset. I have used it a couple of times. It takes a while to respond.
CV109 can be useful in allowing access to alternative CV range (basically have two full sets of CVs which are swapped by CV109). Its worth setting CV109 to an odd number to gain access to the second set, fiddle with those for a while, and if still stuck, then go back to the first set by setting the value to an even number (0). That seemed to fix some of the wierdness in mine, though still not 100% happy that I understand what is going on.

Half speed in reverse is caused by bit 2 (numbering bits 0,1,2, etc) of CV116

To make decoder work satisfactorially in my 04, I ended up with:

CV1 = 7 (I am using short addresses)
CV3 & CV4 = 4
CV5 = 255
CV6 = 84 Wanted low speed range to be more controllable, hence somewhat skewed downwards, couldn't make a custom speed table behave to my satisfaction, but suspect some of the JMRI files may be screwed and ran out of time.
CV29 = 1 (guess who wired the chip to motor leads without checking !!).
CV50 = 255 (regulation influence, standard value)
CV51 = 30 P-value (much reduced from default)
CV52 = 15 I-value (kept in proportion to CV51, seemed to be OK, so stopped fiddling).
CV64 = 200 ( cuts top speed, see the Arnold Web Commentary on the Trans decoders and note below)
CV116 = 3 (Half speed operates on F3, reverse speed is normal, bit 3 can give 65% reverse speed)

NOTE that there is an error in one of the JMRI files for the DCX in that it has CV64 incorrectly labelled in the definitions as CV49 !
Setting CV49 to a non-zero value causes the half-speed (F3) to turn off, and may cause some of the other wierdness.
Faulty JMRI file on CV64 is "CT_Elektronik_DCX_new", not to be confused with "CT_Elektronik_DCX_new2"
I've not fully reconciled the JMRI files to my satisfaction, so cannot say which is properly correct on all aspects.

I will fiddle some more with the values after the 2mm Scale Association Expo at the weekend.

If still stuck, drop me email via the contacts link on the 2mm Scale Association website and I'll try to get my full set of CV's over to you, I don't read the MRforum too frequently.

- Nigel
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