5.21.3
Measuring methods and measuring ranges of SM 431; AI 8 x 14 Bit
Measuring methods
You can set the measuring method at the input channels:
● Voltage measurement
● Current measurement
● Resistance measurement
● Temperature measurement
You specify the setting by means of the measuring range modules on the module and the
"Measuring type" parameter in STEP 7.
Circuit variants for the channels
Two channels are set in each case with the measuring range module. There are therefore
restrictions as regards the measuring method for the adjacent channels 0/1, 2/3, 4/5 and 6/7,
as shown in the following table:
Table 5-55
Selection of the measuring method for channel n and channel n+1 of the SM 431; AI 8 x 14 Bit
(6ES7431-1KF10-0AB0)
Measuring method,
channel n
Measuring method, channel n + 1
Deacti‐
vated
Voltage Current
4-DMU
Current
2-DMU
R-4L
R-3L
RTD-4L
RTD-3L
TC-L
Disabled
x
x
x
x
x
Voltage
x
x
x
Current 4-wire trans‐
ducer
x
x
Current 2-wire trans‐
ducer
x
x
4-conductor resistor
x
3-conductor resistor
x
4-conductor thermal
resistor
x
3-conductor thermal
resistor
x
Thermocouples
x
x
x
Example
If you select "current (2-wire transducer)" for channel 6, you can only disable the measuring
method or set "current (2-wire transducer)" for channel 7.
Analog modules
5.21 Analog input module SM 431; AI 8 x 14 Bit (6ES7431-1KF20-0AB0)
S7-400 Automation System Module Data
262
Reference Manual, Ausgabe 11/2016, A5E00850736-08