Siemens Simatic S7-400 - Manual (Page 264)

Analog Modules
5-48
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Connecting Two-Wire Transmitters
+24 V
Sensor, for example,
pressure gauge
+
–
L +
M+
M
-
M+
M
-
M
Two-wire
transmitter
Two-wire
transmitter
+
–
M
P
P
M
ANA
* Connection required in the case of modules with M
ANA
*
Figure 5-10 Connecting Two-Wire Transmitters to an Isolated AI
SM 431; 8 x 13 Bit: Connecting Two-Wire Transmitters
Because the supply voltage for the two-wire transmitters is not fed by the SM 431;
8 x 13 Bit, you must supply the sensors separately with 24 V.
+24 V
Sensor, for example,
pressure gauge
+
–
MI
+
M–
Two-wire
transmitter
Two-wire
transmitter
+
–
M
ANA
M
V+
M
V+
M
I
+
M–
M
I
+
MI
+
M
P
P
Figure 5-11 Connecting Two-Wire Transmitters to an SM 431; 8 x 13 Bit