Connectivity, TCP Ports & Serial I/O
322 Console Server & RIM Gateway User Manual
RS-422 uses a full duplex transmit on TX+ (Transmit Data +) / TX- (Transmit Data -) pair, receive on RX+ (Receive Data +) /
RX- (Receive Data –) pair.
RS-485 uses half duplex over single pair. For RS-485 which is a 2-wire bus that drives D+ and D- from a native 4-wire
interface you need to loop 3-6 and 2-7 on the DB-9.