The Serial Out is quite useful, it amazes me why folks hesitate to hook it up...
Only the Serial Out on the Cruise M has sufficient drive to run the Railsounds. When you attach the Cruise M to the R2LC serial line, it affects the Serial data levels on pin 24, and as a result the data going to Railsounds is not strong enough - and Railsounds quits working. The best way to install the Cruise M is to isolate the serial data from the R2LC radio pin 24 and place the output of the R2LC pin 24 into the Cruise M *only*, and then the output on pin2 of the Cruise M back into the isolated serial line. This will keep the signal levels proper for the Railsounds to work.
I designed the Cruise M board, so ask questions and I will do my best to answer them.
jon
Jon,
That's interesting, I tried to use the serial out several times a number of years ago, and I was never successful at getting a proper serial data stream to trigger the sound card. I simply stopped using it, but I'll have to revisit it again with your comments in mind. I just figured there was something I didn't understand about the serial data out line.
FWIW, my usual experience is the CC-M stops working properly before the RailSounds when you just parallel the serial data.
BTW, for the CC-M documention, other than mentioning "Serial Data Out" in the Pin Designations table, that lead is never mentioned in the text that I can see. The example for a K-Line Allegheny shows all three serial signals connected to the same place, feeding pin-1 of the CC-M, no mention of pin-2. This led me to believe that serial data out was for some other function.
On diesels, with the serial data to the RS card going through the motherboard, it would be necessary to find and cut the trace to separate them, and that is also not mentioned.
I did find a mention of pin-2 in this paragraph, but it wasn't clear that using the serial data out was more beneficial than just injecting the horn for configuration changes.
The serial data is repeated on pin-2 of the 10-pin connector on the Cruise “M”. In this
repeated data stream, any configuration changes on the Cruise “M” will inject a
“horn” command. This can be used for confirmation of configuration changes.