CT chip vagaries solved

In an earlier posting I made mention of some problems with CV values in CT Elektronik DCX74 chips. I've now got much further towards a solution. The main lessons being:

1. check carefully which decoder files are used in DecoderPro, some of the CT files are for very old versions of the chips which have different CV layouts. Using those can make a newer chip go haywire.
2. the mapping of half-speed mode to a function key isn't well documented for the DCX74. It is in the DCX75 (German) manual, and there are DecoderPro files available on their JMRI users Yahoo group. With luck the files will find their way to a release version of JMRI/DecoderPro in due course.
3. the movement behaviour for uncoupling is different to that by Zimo. Loco movement seems to be triggered on "function off" rather than "function on". I haven't found a setting which will trigger the operation of a coil at the correct place in the operating sequence. Consequently, I think it will end up as a two function uncoupling sequence; the first to "open" the coupler, the second to move the locomotive. ( Update, December 2008 ; I have now deciphered the CT movement behaviour, and it does all the tricks ! See the 2mm scale 04 elsewhere in the blog. I have updated the JMRI/DecoderPro definitions file to make this considerably less cryptic. ).