With DCC, the command station
sends out up to 180 command packets per second. How many each loco
receives depends on how many locos are being run at the time and the
features used by each one. The Packet Time-Out feature provides a
method to shut the decoder down if it doesn't receive a valid packet
within a specified time.
Most decoders do not have this feature
implemented. The only ones I know of that do are Throttle Up!/ SoundTraxx
sound decoders.
I think the reason that most companies
do not implement this is because of the way it's specified. It's almost
useless for preventing problems. The shortest time it can be set for
is 10 seconds. Considering that every operating decoder should be
getting many packets per second, any decoder that doesn't get one
within two or three seconds is probably out of control. Waiting 10
seconds for it to shut down is enough time for an out-of-control loco
to crash. Fortunately, runaways don't happen often enough to demand
this be implemented in a way to shut locos down sooner.
For Throttle Up! sound decoders,
it can be used to have the decoder go silent after the specified period
of time. When you're finished with a particular loco, and the system
quits sending it packets, 10 seconds later (or more, depending on
how you program it) it will shut down. Other than that, you'll need
the use of Function 8 to turn the sound off. |
