Siemens Simatic M7-400 Reference Manual page 352

Analog Modules
Table 5-74 Parameters of the SM 431; AI 8
Parameter
•
Smoothing
•
Reference junction
(reference to the cold
junction)
1)
If you use the module in ER-1/ER-2, you must set this parameter to "No" because the interrupt lines are
not available in ER-1/ER-2.
2)
Only in the CC (central controller) is it possible to start up the analog modules with the default settings.
3)
The limit values must be within the temperature range of the connected sensor.
4)
Valid for the format of the output temperature and the dynamic reference temperature
Smoothing of the Measured Values
You fill find information that is generally applicable to the smoothing of analog
values in Section 5.6.
The cycle time of the module is a constant in the SM 431; AI 8
dependent on the number of channels that are enabled. It therefore has no effect
on the step response, which is defined by the parameter assignment of
interference frequency suppression and smoothing.
Step Response
Table 5-75 How Response Times Depend on the Parameterized Interference Frequency Suppression
and Smoothing of the SM 431; AI 8
Interference Frequency
S pp essio i H Suppression in Hz
10
50
60
400
The following figures illustrate the contents of Table 5-75. They show the response
time required for a step response before the smoothed analog value is almost
applied to 100%. The figures apply to every change of signal at an analog input.
5-136
16 Bit, continued
Value Range
None
Low
Average
High
None
Internal
Reference temperature value dynamic
16 Bit
Response Time in ms with Parameterized Smoothing:
None
100
20
16.7
10
S7-400, M7-400 Programmable Controllers Module Specifications
2)
Default Parameter
None
Internal Static
Low Average
200 1600
40 320
33.3 267
20 160
Scope
Type
Module
16 Bit that is not
High
3200
640
533
320
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