Analog Modules
5-97
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Circuit Variants of 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 5-58 Selection of the Measuring Method for Channel n and Channel n+1 of the SM 431; AI 8 14
Bit (6ES7 431-1KF20-0AB0)
Meas. Type
Channel n+1
Meas. Type Chan-
nel n
Disabled Voltage
"1 V Voltage
1 to 5 V Voltage
"10 V Current
4-DMU Current
2-DMU R-4L
Disabled x x x x x x
Voltage "1 V x x
Voltage 1 to 5 V x x x
Voltage "10 V x x x
Current four-wire
transmitter x x
Current two-wire
transmitter x x
Resistance
four-conductor x
Example
If you select “current (two-wire transmitter)” for channel 6, you can only disable the
measuring method or set “current (two-wire transmitter)” for channel 7.
Circuit for Resistance Measurement
The following conditions apply when measuring the resistance with the SM 431;
AI 8 x 14 Bit:
Table 5-59 Channels for Resistance Measurement of the SM 431; AI 8 14 Bit (6ES7431-1KF20-0AB0)
Measuring Type Parameter Permissible
for Channel n Condition
Resistor
(four-conductor terminal) 0, 2, 4 or 6 You must disable the(“Measuring Type” parameter for
channels n+1 (1, 3, 5, 7).
The reason The connections of channel n+1 are used
to supply the resistance that is connected to
channel n.