I am using 75176 drivers for multi processor communication.'A' line is pulled low and 'B' line is pulled high with 4.7k res.No termination resistor is used.

The problem seems to be that the processors are reading lot of garbage when the communication line is idle.This is happening even during bench testing.

Since the information exchanged is very little I am not using any CRC checking.

What is the method to ensure only valid charecters are read. I am only using a parity check.