SoundTraxx SoundCar Users Guide - Manual (Page 13)

Tsunami SoundCar User’s Guide Page 9
The decoder is unlocked when the value in CV 15 matches the value in
CV 16. Otherwise, the decoder is locked and cannot be reprogrammed in
either Operations Mode or Service Mode. Moreover, a locked decoder cannot
be reset to its factory defaults until it is unlocked. SoundTraxx decoders are
shipped from the factory with all CVs unlocked (CVs 15 and 16 are both set
to 0).
Note: If the decoder is unlocked, changing the value in CV 16 will instantly
lock the decoder. You must then set CV 15 to the value programmed into
CV 16 to unlock the decoder again.
If you decide to use the CV locking feature for a multi‑decoder installation,
you must first set the lock code in CV 16 in each decoder prior to installing
the next one. Otherwise, all of the decoders will have the same lock code
and the lock/unlock feature will not work. To ensure the lock/unlock feature
will work correctly in a multi‑decoder installation, install one decoder and
program its lock code. After you have locked the first decoder, install the
second decoder and set its lock code. Because the first decoder is locked, it
will be unaffected while you program the second decoder (unless you happen
to accidentally set the lock code of the two decoders to the same value. If
this happens, disconnect the second decoder and start over). Repeat this
procedure until all decoders have been installed and their respective lock
codes set.
It is a good idea to create a system to help you remember all those lock
codes. As an easy example, you might choose to set the lock code for motor
decoders to 1, sound decoders to 2, and function decoders to 3. In any event,
keeping CV 15 set to 0 will guarantee that the decoder stays locked until you
are ready to program.
If You Forget the Lock Code
As there are only eight possible combinations, you can easily determine a
forgotten lock code using trial and error with the following procedure:
Place the model on the programming track and set CV 15 to 0. Then, try to
read the value programmed into CV 16. If CV 16 does not read back, the
decoder is locked. Set CV 15 to 1 and try reading CV 16 once more. Again,
if CV 16 does not read back, the decoder is locked. Program CV 15 to 2 and
try reading CV 16 again. Continuing in this manner, you should eventually
find the value programmed into CV 16, as it can only be a value from 0 to 7. If
you have set CV 15 to all eight values from 0 to 7 and the decoder still does
not respond, there may be a problem with the installation, the programming
track, or even the decoder itself. Investigate further and contact SoundTraxx
customer support as necessary.
If you do not have access to a programming track with read‑back capabilities
(or are uncertain if yours is working properly), you can also use Operations
Mode to determine the lock code. To do this, alternately program CV 15
and another CV to a value where there is a known response. For example,
changing CV 128 (Master Volume Control) should produce audible feedback
Basics of Programming