BECKHOFF CX9000 - Manual (Page 30)

Product overview
28 Embedded PC
CX9000-N031 connections
The CX9000-N031 system interface features two RS422 / RS 485 interfaces, COM1 and COM2 (9 pin Sub-D plug
connector). The maximum baud rate on all channels is 115 kBit. The pin assignment for all interfaces is equal and
described below. The interface parameter can be set in the operating system or in the PLC program.
RS232 COM interface (connector):
Pin assignment COM interface:
PIN Signal Type Description
2 TxD+ Data-Out + Transmit 422
3 RxD+ Data-In + Receive 422
5 GND Ground Ground
6 VCC VCC +5V
7 TxD- Data-Out - Transmit 422
8 RxD- Data-In - Receive 422
For RS 485 Pin 2 and 3 ( Data +) as well as Pin7 and 8 (Data -) have to be connected..