Siemens Simatic S7-400 - Manual (Page 345)

Analog Modules
5-129
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
5.23.2 Measuring Methods and Measuring Ranges of the SM 431;
AI 8
RTD 16 Bit
Measuring Methods
As the measuring method for the input channels, you can set the temperature
measurement.
Unused Channels
Disable the “Measuring Type” parameter for unused channels. In this way you
shorten the scan time of the module.
Measuring Ranges
You set the measuring ranges with the “Measuring Type” parameter in STEP 7.
Table 5-73 Measuring Ranges of the SM 431; AI 8 x RTD x 16 Bit
Method Selected Measuring Range Description
RTD-3L: Thermal resistor
(linear, three-conductor
terminal)
(temperature
measurement)
Pt 100 standard
Pt 200 standard
Pt 500 standard
Pt 1000 standard
Ni 100 standard
You will find the digitized analog values
in Section 5.3.1 in the temperature
range
RTD-4L: Thermal resistor
(linear, four-conductor
terminal)
(temperature
measurement)
Ni 100 standard
Ni 1000 standard
Default Settings
The default settings of the module in STEP 7 are “Thermal resistor (linear,
3-conductor terminal)” for the measuring method and “Pt 100 standard” for the
measuring range. You can use this measuring method with this measuring range
without parameterizing the SM 431; AI 8
RTD 16 Bit with STEP 7.