Siemens Simatic M7-400 Reference Manual page 322

Analog Modules
Unused Channels
Unused channels can usually be left open. Put the measuring range modules in
position "B". You can improve the noise immunity of the module in a measuring
environment with serious interference by connecting M– and chassis ground.
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 by means of the measuring range modules on the
module and the "Measuring Type" parameter in STEP 7.
Table 5-63 Measuring Ranges of the SM 431; AI 16 x 13 Bit
Method Selected
" 1 V
U: Voltage
1 to 5 V
2DMU: Current 4 to 20 mA
(two-wire transmitter)
4DMU: Current 4 to 20 mA
(four-wire transmitter)
" 20 mA
Default Settings
The default settings of the module in STEP 7 are "Voltage" for the measuring
method and "" 10 V" for the measuring range. You can use this combination of
measuring method and measuring range without parameterizing the SM 431;
AI 16 13 Bit inSTEP 7.
5-106
Measuring Range Measuring Range
(Type of Sensor) Module Setting
" 10 V
S7-400, M7-400 Programmable Controllers Module Specifications
Description
A You will find the digitized analog
values in Section 5.3.1 in the l i S
B
voltage measuring range
D To supply these transmitters with
current you must connect 24 V to
the L+ and M front connector
terminals.
You will find the digitized analog
values in Section 5.3.1 in the
current measuring range
C You will find the digitized analog
values in Section 5.3.1 in the
current measuring range
ti 5 3 1 i th
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