Measuring Methods And Measuring Ranges Of Sm 431; Ai 8 X 13 Bit - Siemens SIMATIC S7-400 Reference Manual

Analog modules
5.19 Analog input module SM 431; AI 8 x 13 Bit (6ES7431-1KF00-0AB0)
5.19.3

Measuring methods and measuring ranges of SM 431; AI 8 x 13 Bit

Measuring methods
You can set the measuring method at the input channels:
● Voltage measurement
● Current measurement
● Resistance measurement
You perform the setting with the "measuring method" parameter in STEP 7.
Circuit for resistance measurement
The following conditions apply when measuring the resistance with the SM 431; AI 8 x 13 Bit:
Table 5-46 Channels for resistance measurement of the SM 431; AI 8 x 13 Bit
Measuring type parameter
Resistance
(4-conductor connection)
Unused channels
Unused channels can be left open. You can improve the noise immunity of the module in a
measuring environment with serious interference by short-circuiting the channels and
connecting to M
"deactivated". This reduces the module's cycle time.
Measuring ranges
Set the measuring ranges at the "measuring range" parameter in
Table 5-47 Measuring ranges of the SM 431; AI 8 x 13 Bit
Selected measuring method
V: Voltage
2DMU: Current
(2-wire transducer)
236
Permissible
for channel n
0, 2, 4 or 6 You must disable the "Measuring type" parameter for channels n+1 (1, 3,
5, 7).
Reason: The connections of channel n+1 are used to supply the resistance
that is connected to channel n.
. For unused channels, set the "measuring method" parameter to
ANA
Measuring range
±1 V
1 V to 5 V
±10 V
4 to 20 mA
Condition
Description
The digitized analog values are listed in the section "Repre‐
sentation of analog values for output channels" in the voltage
measuring range.
The digitized analog values are listed in the section "Repre‐
sentation of analog values for output channels in the current
measuring range".
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
STEP 7 .