Short Address Programming Note
When programming the short address (CV01) in your DZ121, the decoder will automatically set CV19 to 0, CV29 to 0, CV 55 to 80, CV56 to 30 & CV57 to 0. This is done to insure compatibility with DCC systems that only recognize short addressing (2 digit mode). When using long addressing (4 digit addressing) these CV's are not affected.
After changing the short address (CV01), you will probably want to change CV29 to 06 or another appropriate value based on your operations. You can do this on the programming track or, if you forget, you can use Operations Mode to do this once the loco is back on the layout.
Setting CV19 to 0 clears consisting (this is required for NMRA compatibility).
CV 55, 56 & 57 control the decoder's Back EMF Speed Stabilization feature. Programming the short address will return these values to the default values for BEMF and will turn BEMF OFF. If you wish to use BEMF after programming a new address, you can begin by programming CV57 to a value of 06. This will give good performance with most brands of locomotives. If the locomotive surges while using BEMF use a lower value for CV56. It may also be necessary to adjust CVs 55, 56 & 57 to achieve the motor performance desired for your particular locomotive.