Siemens S7-1200 - Page 974

Technical specifications
A.14 Communication interfaces
S7-1200 Programmable controller
974 System Manual, 03/2014, A5E02486680-AG
Table A- 247 Power supply
Technical data
CB 1241 RS485
Power loss (dissipation)
1.5 W
Current consumption (SM Bus), max.
50 mA
Current consumption (24 VDC) max.
80 mA
CB 1241 RS485 (6ES7 241-1CH30-1XB0)
①
Connect "TA" and TB" as shown to terminate the network. (Terminate only the end devices on the RS485 network.)
② Use shielded twisted pair cable and connect the cable shield to ground.
You terminate only the two ends of the RS485 network. The devices in between the two end
devices are not terminated or biased. See the S7-1200 System Manual section on "Biasing
and terminating an RS485 network connector"
Table A- 248 Connector pin locations for CB 1241 RS485 (6ES7 241-1CH30-1XB0)
Pin
9-Pin connector
X20
1
RS485 / Logic GND
--
2
RS485 / Not Used
--
3
RS485 / TxD+
3 - T/RB
4
RS485 / RTS
1 - RTS
5
RS485 / Logic GND
--
6
RS485 / 5 V Power
--
7
RS485 / Not used
--
8
RS485 / TxD-
4 - T/RA