Siemens S5-155U System Manual page 465

The 466 Analog Input Module
+
U
E2
-
+
U
-
CM2
U
E1
U
CM1
U
E1/2 : Input Voltage
U
CM1/2 : Common-Mode Voltage
U
ISO : Potential Difference
: Equipotential: this potential is established by the sensor reference potential
(external reference potential)
Figure 9-32 Connecting Sensors to the 466 Analog Input Module (Differential Measurement)
9 - 94
The channels have the following designations on the module:
Channel 0: M0+
M0-
Channel 1: M1+
M1-
: :
Channel 15: M15+
M15-
Channels are arranged in groups of four, for which you can set
separate measuring ranges:
Channel group I: Channels 0 to 3
Channel group II: Channels 4 to 7
The following figure shows the connection of sensors to the module.
You must observe the following condition:
U + U < 12 V
E CM
(i.e. the sum of the set voltage range and common-mode voltage must
be less than 12 V;
current measuring ranges correspond to a voltage of 2.5 V).
Analog Input Module
M +
M -
MUX
M +
+
M -
-
+
0 V
-
ext
U
ISO
0 V Bus
System Manual
C79000-B8576-C109-03