I am trying to establish a DCC controlled layout using a DIGITRAX ZEPHYR DCS50 command control.  I have purchased three BACHMANN DCC-EQUIPPED LOCOMOTIVES and cannot, using the DIGITRAX manual's proceedure for CHANGING THE DECODER ADDRESS, change the decoder address.  An error message telling me the DCS50 is not able to read the decoder appears on the DCS50's display whenever I try either on a PROGRAMMING TRACK or the main layout.
Please pass proper proceedures or other gems of wisdom regarding decoder address changes along if possible.
Thanks, P.D.

Having difficulty changing the decoder address of Bachmann GP40 diesel locomotive.  Am using Digitrax Zephyr DCC system and keep getting error message "d nA" when trying to change address or CV values of new locomotive.  Any suggestions for a successful solution?