Tricky one this...

1. Is it that you've got the SERIN syntax slightly screwed... You wrote...

Serin rs232t,t2400,1000,noresp1,["AZ=",byte1]

should it not be...

Serin rs232t,t2400,1000,noresp1,["AZ="],byte1

otherwise byte1 becomes part of your qualifier... and therefore you're not missing your reply, it's just not qualifying.

2. Or is it "just too late", or "seriously" too late?

If it's the former, you might get away with trimming your qualifying condition and dumping the first character like so...

Serin rs232t,t2400,1000,noresp1,["Z="],byte1

3. The best thing to do is to capture and dump the entire reply from the device and work out how much of the expected reply is missing before determining the best course of action to deal with it.

Melanie