Siemens Simatic S7-400 - Manual (Page 306)

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 M
ANA
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
MUL
TIPLEXER
Bus S7-400
Bus control
A
D
Bus S7-400
Bus S7-400
Measuring
3
range
module
Measuring
0
range
module
MANA
M
ANA
Figure 5-30 Block Diagram of the SM 431; AI 8 x 14 Bit