Properties Of The Rs422/485 Interface - Siemens SIMATIC ET 200SP Manual

2.4.2

Properties of the RS422/485 interface

Definition - RS422/485 interface
The RS422/485 (X27) interface is a differential voltage interface for serial data transmission.
Properties - RS422/485 interface
The RS422/485 (X27) interface has the following properties and meets the following
requirements:
Type
BaseUnit terminals
RS422 signals:
RS485 signals:
Max. data transmission rate: 115.2 kbps
Max. cable length:
Standard:
CM PtP communication module (6ES7137-6AA00-0BA0)
Manual, 01/2013, A5E03790792-01
Differential voltage interface
Terminals connected to the electronics module (see RS232 and
RS422/485 interface of the communication module (Page 17) for
assignment)
T (A), R (A), T (B), R (B), GND; all signals are isolated against the
backplane bus and the load voltage
R/T (A), R/T (B), GND; all signals isolated against backplane bus and
load voltage
1200 m; cable type LIYCY 3 x 2 x 0.14. T(A)/T(B) and R(A)/R(B)
twisted in pairs.
DIN 66259 Parts 1 and 3, EIA-RS422/485, CCITT V.11
Product overview
2.4 Properties of the interfaces
15