Basics of Programming
As each DCC system is different, the procedure for programming a CV will vary depending upon the system. Unfortunately, we cannot provide detailed instructions to cover every command station and have to assume that you have some level of understanding regarding it’s capabilities and operating procedures. For specific programming procedures, please consult your DCC system manual.
Locking and Unlocking CVs
The CV Lock/Unlock is a relatively new feature available in some DCC decoders which allows you to program a decoder without the danger of overwriting the programming in another. This especially useful in installations where multiple decoders are used. For example, if you have installed a function decoder in addition to the sound decoder, you may wish to lock the CVs after programming to prevent accidentally programming one or the other.
To use the CV Lock feature implemented in CV 15 and 16, Bit 0 of CV 30 must first be set to 1 (the default value is 0). This is to avoid inadvertently locking the decoder when the CV Lock feature is not needed.
CV 15 and 16 are used for locking and unlocking the decoder. CV 15 is the Unlock Code and may be programmed to any value between 0 and 255 regardless of whether the decoder is locked or unlocked. CV 16 is the Lock Code and may be set to any value between 0 and 7 but only when the decoder is unlocked. Attempts to program CV 16 with a value greater than 7 will be ignored.
The decoder is unlocked when the value in CV 15 matches the value in CV 16. Otherwise the decoder is locked and can not be programmed in either operations mode or service mode. Further, a locked decoder can not be reset to its factory defaults until it is first unlocked. Tsunami decoders are shipped from the factory with all CVs unlocked, that is, CV 15 and 16 are both set to 0.
Note that if the decoder is unlocked, changing the value in CV 16 will instantly lock the decoder. You must then set CV 15 to the same value as was just programmed into CV 16 to unlock the decoder again.
If you decide to use the CV Locking feature for a multi-decoder installation, each decoder installed inside that locomotive must first have its Lock Code in CV 16 set prior to installation of any other decoders. Otherwise, all the decoders will have the same Lock Code and the feature will not work. The easiest way to go about this is to first install one decoder and program its Lock Code. Then install the next decoder and program its Lock Code. Since the first decoder is now locked it will be unaffected by the programming of the second decoder (unless you accidentally set the Lock Code of the two decoders to the same value. If this happens you will need to disconnect one decoder and start over). Continue in this manner until all decoders have been installed and their Lock Codes have been set.
Tsunami Steam Sound User’s Guide