Siemens Simatic S7-400 - Manual (Page 265)

Analog Modules
5-49
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Connecting Four-Wire Transmitters
M+
M–
M+
M–
M
ANA
Sensor,
for example,
pressure gauge
+
–
Four-wire
transmitter
+
–
U H
* Connection required in the case of modules with M
ANA
P
P
* *
Figure 5-12 Connecting Four-Wire Transmitters to an AI
SM 431; 8 x 13 Bit: Connecting Four-Wire Transmitters
To ensure that the permissible value for U
CM
is not exceeded, you must connect
the M– cables to M
ANA
.
M
Sensor, for example,
pressure gauge
+
–
Four-wire
transmitter
+
–
U H
M
I
+
MI
+
M–
M
V+
M
V+
M
I
+
M
I
+
M–
P
P
Figure 5-13 Connecting Four-Wire Transmitters to an SM 431; 8 x 13 Bit