Parameters Of The Channel Pairs; Sensor Evaluation - Siemens SIMATIC ET 200SP Equipment Manual

Parameters/address space
4.2 Explanation of parameters
4.2.3

Parameters of the channel pairs

4.2.3.1

Sensor evaluation

Overview
Select the type of sensor evaluation with the "Sensor evaluation" parameter:
• 1oo1 evaluation
• 1oo2 evaluation, equivalent
• 1oo2 evaluation, non-equivalent
1oo1 evaluation
The sensor uses only one input channel for the 1oo1 evaluation.
1oo2 evaluation, equivalent/non-equivalent
With a 1oo2 evaluation equivalent/non-equivalent, two input channels are occupied by:
• One two-channel sensor
• Two one-channel sensors
• One non-equivalent sensor
The input signals are compared internally for equivalence or non equivalence.
Note that in 1oo2 evaluation, two channels are combined into a channel pair. The number of
available process signals of the F-module is reduced accordingly.
Discrepancy analysis
When using a two-channel sensor or two one-channel sensors which measure the same
process variable, the sensors interact with a slight time delay due to the limited precision of
their arrangement.
The discrepancy analysis for equivalence/non equivalence is used for fail-safe applications to
prevent errors from time differences between two signals for the same function. The
discrepancy analysis is initiated when different levels are detected in two associated input
signals (when testing for non equivalence: the same levels). A check is made to determine
whether the difference in levels (when testing for non equivalence: the same levels) has
disappeared after an assignable time period, the so-called discrepancy time. If not, this means
that a discrepancy error exists.
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Digital input module F-DI 8x24VDC HF (6ES7136-6BA01-0CA0)
Equipment Manual, 10/2021, A5E50578307-AA