Siemens S7-1200 - RS232, RS422, and RS485; CB 1241 RS485 Specifications

Technical specifications
A.14 Communication interfaces
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
973
A.14.4
RS232, RS422, and RS485
A.14.4.1
CB 1241 RS485 specifications
Note
To use this CB, your CPU firmware must be V2.0 or higher.
Table A- 245 General specifications
Technical data
CB 1241 RS485
Order number
6ES7 241-1CH30-1XB0
Dimensions W x H x D (mm)
38 x 62 x 21
Weight
40 grams
Table A- 246 Transmitter and receiver
Technical data
CB 1241 RS485
Type
RS485 (2-wire half-duplex)
Common mode voltage range
-7 V to +12 V, 1 second, 3 VRMS continuous
Transmitter differential output voltage 2 V min. at R
L
= 100 Ω
1.5 V min. at R
L
= 54 Ω
Termination and bias 10K to +5 V on B, RS485 Pin 3
10K to GND on A, RS485 Pin 4
Optional termination Short Pin TB to Pin T/RB, effective termination impedance is 127 Ω,
connects to RS485 Pin 3
Short Pin TA to Pin T/RA, effective termination impedance is 127 Ω,
connects to RS485 Pin 4
Receiver input impedance
5.4K Ω min. including termination
Receiver threshold/sensitivity
+/- 0.2 V min., 60 mV typical hysteresis
Isolation
RS485 signal to chassis ground
RS485 signal to CPU logic common
500 VAC, 1 minute
Cable length, shielded
1000 m max.
Baud rate 300 baud, 600 baud, 1.2 kbits, 2.4 kbits, 4.8 kbits, 9.6 kbits (default),
19.2 kbits, 38.4 kbits, 57.6 kbits, 76.8 kbits, 115.2 kbits,
Parity No parity (default), even, odd, Mark (parity bit always set to 1),
Space (parity bit always set to 0)
Number of stop bits
1 (default), 2
Flow control
Not supported
Wait time
0 to 65535 ms