Siemens SIMATIC PCS 7 Configuration page 52

3 Configuring the redundant peripherals
3.6 Additional parameter settings for the configuration of the redundant AI modules
Discrepancy time / deviation time
As described in the help for AI modules, the deviation time of AI modules should
be a multiple of the update time. To calculate the update time, the following
parameters must be considered:
Update time of the AI modules
Cycle time of the PROFIBUS (can be ignored if the baud rate is
Update time of the (partial) process images (TPA)
The update time of an analog value for an analog input card, such as 6ES 7331-
7TF01, can be taken from the table 3–6.
First, select the parameter "Integration time / interference frequency suppression".
Then you allocate the number of channels used.
Table 3–6: Analog value for parameters
Principle of
measurement
Integration time /
interference frequency
suppression (per channel)
Integration time error
Integration time in ms
Basic reaction time
including integration time in
ms (per channel)
Basic module execution
time in ms (all channels
enabled)
Smoothing the measured
value
Table 3–7: Examples
Integration time / interference frequency
50 Hz
50 Hz
50 Hz
10 Hz
10 Hz
10 Hz
Configuration of Redundant I/O Modules
Entry-ID: 28430682, V2.0,
Analog value conversion
60 Hz
± 0.05%
16.6
55
440
Step:
None
Weak
Average
Strong
suppression
03/2015
SIGMA DELTA
50 Hz 10 Hz
± 0.04% ± 0.02%
20 100
65 305
520 2440
Time constant: Max module cycle:
1 x cycle time *** 2.44 s
4 x cycle time *** 9.76 s
32 x cycle time *** 78.08 s
64 x cycle time *** 156.16 s
Number of channels
used
1
4
8
1
4
8
1.5 Mpps).
Update time
of module
65 ms
260 ms
520 ms
305 ms
1220 ms
2440 ms
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