> So am I right in my understanding that a DStar 2m radio (such as > IC-V82 + UT-118) will send (or can be made to send) unadulterated > data over the voice+data channel?
Yes*. The footnote being that you can't send any byte sequence. Since the radios use XON/XOFF flow control, those values are obviously out. Some of the radios use the data port for programming as well, so there are some escape sequences that you can't send. D-RATS uses yenc-style escaping to only avoid the specific banned values without having to encode the rest. > Does this mean whatever it receives on the serial port is sent out > as additional data on voice+data more, or is there a comms protocol > on the ICOMs to 'poke' data bytes into a message queue? Correct, what you put in comes out the other end (assuming the note above). There is no protocol you need to speak to the radio. > Q. How useful/important would it be for transmission integrity to > include compression/FEC of 'simple data' on the voice+data link. D-RATS does compression and error detection. At 900 baud, FEC starts to eat up your channel pretty quick. For most connections, framing and checksums provide a good balance of speed and overhead. -- Dan Smith dsmith#danplanet.com, s/#/@/ www.danplanet.com KK7DS
