Analog Modules
5-90 S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
5.20 Analog Input Module SM 431; AI 8 14 Bit;(6ES7431-1KF20-0AB0)
Characteristics
The analog input module SM 431; AI 8 14 Bit has the following features:
Rapid A/D changeover, therefore particularly suitable for highly dynamic
processes
8 inputs for voltage/current measurement
4 inputs for resistance measurement
Unlimited measuring range selection
14-bit resolution
Supply voltage: 24 VDC required only for the connection of 2-wire transmitters
Analog section isolated from CPU
The maximum permissible common mode voltage between the channels and
between the reference potential of the connected sensors and MANA is 8 VAC

Block Diagram of the SM 431; AI 8 14 Bit

CH0
CH1
CH6
CH7
+5V
0V
0V
– 15V
+ 5V
+ 15V
L+
M
ENABLE
MULTIPLEXER
Bus S7-400
Bus control
A
D
Bus S7-400
Bus S7-400
Measuring
3
range
module
Measuring
0
range
module
MANA
MANA
Figure 5-30 Block Diagram of the SM 431; AI 8 x 14 Bit