Yes, but if he is doing something like modbus for instance, he only has the node#, correct number of bytes to collect, and then the timeout or Silent time.

Then he would have to verify the data with a crc check before proceding, this of course is if he is using MB RTU and Not ASCII, or his own home grown protocol.

Only reason I menioned modbus is because he mentioned a 485 network, Node ID, and Broadcast so it kind of sounds like it.

Richard