Details of the problem:
Hello, we have purchased 132 sets access controller of RS485 Communication way from your company, use two FC-08 converter and separate with 2 wires, the first wire has 103sets access controllers, the second wire has 29 sets, when connected them, we found the second wire communication failure, it has a communication indicator normal light which behind all boards, is not the same as the normal time, what’s wrong of that?
Expert answer:
If communication indicator RX light is always opened, that means it has one device connect opposite with A and B in RS485 wire. Please check the circuit to find out the wrong device and connect it in correct way.
