Measuring Ranges Of The Sm 331; Ai 8 X 12 Bits - Siemens SIMATIC S7-300 Reference Manual

Special characteristics of unused channels for some measuring ranges
Since configured inputs can remain unused because of the channel group
generation, you must take note of the following special characteristics of these
inputs to enable the diagnostic functions on the used channels.
• Measuring range 1 to 5 V: Connect the unused input in parallel with a used
input of the same channel group.
• Current measurement, 2-wire transmitter:
There are two ways to use the channels:
a) Leave the unused input open and do not enable diagnostics for this
channel group. Otherwise, if diagnostics are enabled, the analog module
triggers a single diagnostic interrupt and the SF LED of the analog module
comes on.
b) Connect the unused input with a resistance of 1.5 to 3.3 kW. You may then
enable diagnostics for this channel group.
• Current measurement 4 to 20 mA, 4-wire transmitter: Connect the unused
input in series with an input of the same channel group.
Special characteristic when all channels are disabled
If you disable all input channels of the module and enable diagnostics when
parameterizing the analog input module SM 331; AI 8
not indicate that the "external auxiliary voltage" is missing.
Measuring ranges
You perform the setting of the measuring ranges by means of the measuring range
modules on the module and with the "measuring method" parameter in STEP 7.
Table 4-67 Measuring Ranges of the SM 331; AI 8 x 12 bits
Method Selected
U: Voltage
TC-I:thermocouple
(internal compensation)
(thermovoltage
measurement)
TC-E: Thermocouple
(external compensation)
(thermovoltage
measurement)
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Measuring Range
(Type of Sensor)
" 80 mV
" 250 mV
" 500 mV
" 1000 mV
" 2.5 V
" 5 V
1 to 5 V
" 10 V
Type N [NiCrSi-NiSi]
Type E [NiCr-CuNi]
Type J [Fe-CuNi]
Type K [NiCr-Ni] Type K [NiCr-Ni]
Type L [Fe-CuNi]
Measuring Range
Module Setting
A You will find the digitized
analog values in Section
4.3.1 in the voltage
measuring range
B
A You will find the digitized
analog values in Section
4.3.1 in " 80 mV the voltage
measuring range
Analog Modules
12 bits, the module does
Description
4-123