BECKHOFF CX2020 - Manual (Page 32)

Mounting and wiring
3.10 RS232 connections (CX20x0­N030)
The CX20x0­N030 system interface provides an RS232 interface, COM1 (X300). It is implemented on a 9­
pole Sub­D pin strip. If more than one interface is required the system can be extended via the Terminal Bus
(K­ or E­bus) or Bus Terminals (KL/EL6001) which provide serial interfaces. The pin assignment is shown at
the bottom of the page.
The maximum baud rate on both channels is 115 kbit. The interface parameters are set via the operating
system or from the PLC program.
RS232 COM interface (connector)
Table 6: Pin assignment of the COM interface
PIN Signal Type Description
1 DCD Signal in Data Carrier Detected
2 RxD Signal in Receive Data
3 TxD Signal out Transmit Data
4 DTR Signal out Data Terminal Ready
5 GND Ground Ground
6 DSR Signal in Dataset Ready
7 RTS Signal out Request to Send
8 CTS Signal in Clear to Send
9 RI Signal in Ring Indicator
CX2020, CX2030, CX2040 32 Version 1.2