Siemens SIMATIC S7-300 Module data - Page 322

Analog Modules
4-116
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Terminal Connection Diagram and Block Diagram of the SM 331; AI 8 x 12 bits
M
3
*
Comp–/ Mana
Fault indicator – red
Thermocouples,
Voltage measurement
Current measurement
Resistance test
M
0 +
M
0
*
M
1 +
Comp +
SF
Internal
supply
M
M
L+
Current
source
Multi-
plexer
Meas. range
module
Ext.
compensation
None
AD
C
Isolation
Backplane
bus
interface
SF
+
Int.
Comp.
CH0
M
0 +
CH0
M
0
*
I
C0 +
CH1
M
1
*
I
C0
*
M
2 +
CH2
M
1 +
CH2
M
2
*
M
1
*
M
3 +
CH3
I
C1 +
I
C1
*
M
4 +
M
4
*
M
5 +
CH4
M
2 +
CH4
M
2
*
I
C2 +
CH5
M
5
*
I
C2
*
M
6 +
CH6
M
3 +
CH6
M
6
*
M
3
*
M
7 +
CH7
I
C3 +
M
7
*
I
C3
*
Comp
24V
T
Figure 4-40 Module View and Block Diagram of the Analog Input Module SM 331; AI 8 x 12 bits
The input resistances depend on the measuring range selected (see Technical
Specifications).