Cm 1241 Rs485 And Rs232 - Siemens SIMATIC S7-1200 Manual

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 section on "Biasing and terminating an RS485
network connector".
A.8.4.2

CM 1241 RS485 and RS232

Table A- 62 General specifications
Technical data
Dimensions (W x H x D)
Weight
Power loss (dissipation)
From +5 VDC
Table A- 63 Transmitter and Receiver
Technical data
Type
Transmitter Common mode voltage range
(RS485)
Transmitter differential output voltage 2 V min. at R
Termination and bias
Transmitter Transmitter output voltage
(RS232)
Transmit output voltage
Receiver Receiver input impedance
Receiver threshold/sensitivity
Receiver input voltage
(RS232 only)
Isolation Signal to chassis ground
Signal to CPU logic common
Cable length, shielded (max.)
Baud rate
Parity
Number of stop bits
Easy Book
Manual, 11/2011, A5E02486774-04
CM 1241 RS485
30 x 100 x 75 (mm)
150 grams
1.1 W
220 mA
Description
RS485 (2-wire half-duplex)

RS232 (full-duplex).

-7 V to +12 V, 1 second, 3 VRMS continuous
1.5 V min. at R
10K Ω to +5 V on B, PROFIBUS Pin 3
10K Ω to GND on A, PROFIBUS Pin 8
+/- 5 V min. at R
+/- 15 VDC max.
RS485: 5.4K Ω min. including termination

RS232: 3 K Ω min.

RS485: +/- 0.2 V min., 60 mV typical hysteresis

RS232: 0.8 V min. low, 2.4 max. high 0.5 V typical

hysteresis
+/- 30VDC max.
500 VAC, 1 minute
RS485: 1000 m.

RS232: 10 m.

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,
No parity (default), even, odd, Mark (parity bit always set to 1),
Space (parity bit always set to 0)
1 (default), 2
Technical specifications
A.8 Communication interfaces
CM 1241 RS232
30 x 100 x 75 mm
150 grams
1.1 W
220 mA
= 100 Ω
L
= 54 Ω
L
= 3K Ω
L
279