[Matt Krass]

Originally Posted by Al Skierkiewicz

I think what you are asking is "Can I use the relay outputs as a serial digital link to the digital inputs on another RC?" The answer is maybe but there are some other things that will get in your way besides just the electronic interface. I will let Mike or Kevin answer more on this, but the digital inputs are scanned. That means that the RC isn't looking at them all the time so to act as a serial port you will need to keep data there long enough to be accurately read. In normal serial communications, the transceivers "handshake" and both will know when data has been transmitted and when it is accurately received.
The relay outputs are really intended to control the IFI Spike relays. Being the kind of output that does not need to rapidly turn on and off, these outputs may in fact, be to slow for your use. That being said, we have used the digital inputs for data transfer from a custom circuit to the RC.

I don't think he meant the relay outputs either (I know I'm very annoying ) it would seem from the spec sheet for the RC that 16 digital I/O lines are just that, input/output lines, so you should be able to send a signal from them. These should be faster than the relay outputs right? I believe his intent was using purely the digital I/O lines, but I could be wrong. However if he is would I be correct in saying it's electrically safe/compatible?