KB720 Trouble reading CV values with SFX064D

If you have trouble reading back CV's on the programming track, this may be due to insufficient current draw on the SFX064D function leads. You can always just re-program the CV value into a CV to get the desired results, even though reading CVs does not work. OPs mode is recommended for programming all CVs except CV01, CV17 & CV18 (2 digit and 4 digit addresses). If a second DCC decoder is present that is not Sound FX compatible then correct readback of CV data is not possible, since the NMRA CV readback was not designed for multiple decoder readback.

KB717 Using SFX064D with other DCC Decoders

The sound project loaded into this decoder can be operated independently of any other DCC motor or function decoder. If another non-Sound FX compatible DCC decoder is connected to the track leads then CV readback of SFX064D Sound CV's and PR2/PR3 SoundTest modes may not be possible. Note that it is always possible to Write CV values using Operations mode or a Service Mode programming track, even if CV Read is inoperative.If the connected function loads are insufficient for CV readback or an incompatible DCC decoder is also connected, it is still possible to download a complete sound project by ...

KB727 SFX064D Sound Decoder Installation Instructions

1) Connect the Red and Black track wires from the 9 pin Track and Function harness to the locomotive track power connections.2) Connect the function leads that are to be used from the 9pin Track and Function harness. Note that to be able to readback Sound FX CV's a combination of function lead loads of at least 60mA at 12volts should be connected to these function leads. Insulate the unused function leads so they cannot short to the locomotive frame or track power.3) Mount the 28mm speaker attached to the 10pin sound feature harness in an appropriate sound enclosure. Be ...