Here is my best recollection of some of my various attempts at programming the 4-digit address. I tried many, many times in many, many ways - so this is not necessarily a blow-by-blow description!
My initial unsuccessful attempt to program the 4-digit address was on the programming track - by getting to AD4 on my Zephyr and entering/writing the desired code. That's the way I have done most of the decoders I use.
Then I tried unsuccessfully to do it in Ops mode on the main by programming the various CVs (but the failures may have been due to not using the correct sequence as TCS had indicated to me later).
When that failed, I probably went back to the programming track to set the various CVs. I know that sometimes I would not be able to read a CV back after setting it - rec'd the DNR message on the console. Then back to Ops mode on the main. And so on and so on - back and forth between the programming track and Ops mode - until I successfully programmed it in Ops mode on the main following the advice on the sequencing from TCS.
Based on the most recent responses, I decided to try again tonight on the programming track setting CV29, CV17 and CV18 to the desired values. Still no success. Went back to Ops mode on the mainline and successfully set the address to 2527 as desired.
Not sure why I cannot set the address on the programming track; but since I can accomplish what I want in Ops mode, I am satisfied. I shouldn't ever need to change the locomotive address again, so this works for me.
Thanks,
Bart