i4connected Knowledgebase 5.6

The Plausibility check feature

Abstract

Check out this article and learn how the i4connected Plausibility check feature operates the Signals data.

This article describes how the Plausibility Check mechanism operates within the i4connected system.

The Plausibility Check feature will evaluate if each measurement is plausible in comparison with the last one. This measurement difference between the current value and the last measured value is checked against a user-defined constant Delta. The Delta constant represents the maximal absolute variation a signal may have per second.

The Signal Plausibility Delta is defined in the Add / Edit Signal panel.

Palusability_delta.jpg

The Plausibility Delta setting

When a measurement is not plausible, it will be swallowed and a "Data not plausible" alarm will be raised from the source device, with the start date of the first implausible value and end date of the last continuous implausible value.

Warning

If the Signal's parent Device has its alarms suppressed, no alarms will be triggered for not plausible measurements.

Let's take as an example the following situation:

PlausabilityCheck.png

Plausibility Check Example 

In the above set of measurements, an implausible value is detected at the time marker 1:30 AM. As explained above, a "Data not plausible" alarm is raised with the start time 1:30 (the time of the implausible value detection) and the end time 1:45 (the time of detection of the first plausible value after the implausible value was detected).

In the same example, another implausible value is detected at the time marker 3:00 AM. Just like before, the "Data not plausible" alarm is raised with the start time 3:00 and the end time 3:15.

To enable the Plausibility Check feature, the Delta property of the signal should be set to not null. The Delta property values are:

  • null: Plausibility Check disabled;

  • 0.5: Plausibility Check enabled with 0.5 absolute variation threshold.