Siemens Simatic S7-400 - Manual (Page 277)

Analog Modules
5-61
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
+24 V L
+
Q
V
S+
S–
M
ANA
0 V
M
U
ISO
Chassis ground
R
L
Figure 5-21 Connecting Loads to a Voltage Output of an Isolated AO over a
Four-Conductor Connection
Two-Conductor Connection of Loads to a Voltage Output
In the case of a two-conductor connection, connect Q
V
to S+ and M
ANA
to S– on
the front connector. However, this will not produce the accuracy of a four-conductor
connection.
Connect the load to terminals Q
V
and to the reference point of the measuring
circuit M
ANA
of the module.
+24 V L
+
QV
S+
S–
M
ANA
0 V
M
U
ISO
Chassis ground
R
L
Figure 5-22 Two-Conductor Connection of Loads to a Voltage Output of an Isolated AO