Moving Alarm block

This block provides a mechanism for triggering alarms when the incoming data lies outside defined boundaries.

Moving alarm block

Description

In this block you can define rules that trigger an alarm when a certain amount of incoming data lies outside defined boundaries. Specifically, you define boundaries outside of which datapoints are considered to be outliers and you define how many outliers may occur per a chosen number of consecutive samples before triggering the alarm. The boundaries you define may be set as a lower and upper limit respectively or as a number of sigma offsets from the center line.

MOVING ALARM block

Output fields

By default your output fields will be called SELECTEDFIELD_ACTIVE, where SELECTEDFIELD is the input field specified in the rule.

If the same default name is used elsewhere, name clashes will results in _1, ..., _X being appended to the output field name.

Timestamp

Timestamps for the output fields will be set to the timestamp of the last input data point that is considered for the corresponding window.
In the case of the Ignore bad quality input data checkbox being selected, the timestamp of the output field stays the same when bad quality input data occurs.

Quality

Output quality is set to bad when not enough data points exist (in the window) to activate the rule, i.e., when the number of data points is less than the specified Number of outliers to activate rule.
When bad data is not ignored (i.e., when the Ignore bad quality input data option is disabled), then output quality is set to bad when not enough data pointsof good quality exist (in the window) to activate the rule, i.e., when the number of data pointsof good quality is less than the specified Number of outliers to activate rule.
When the Ignore bad quality input data option is enabled, bad quality data points are ignored; they are not added to the window and can in no way alter output quality.
Any bad quality of data on the parameter port fields (for limits) means that the input data quality is bad.
If parameter port values for the Lower Limit are greater than for the Upper Limit, output data quality is bad.
If the parameter port Sigma value is less than 0, output quality is bad.

Value

The rule will trigger when the specified x out of y consecutive points are outside the limits on the same side of the center line. The output value is 1 for a triggered rule and 0 for a rule that is not triggered.

Parameter port

This block uses a parameter port to allow you to populate the limits dynamically via specified fields.

Runnability

To ensure runnability:

The input field (on the input port) must be valid.
At least 1 rule must be defined.
The Maximum window size must be greater than or equal to the Number of outlier points to activate rule.
Both the specified Maximum window size and the Number of outlier points to activate rule must be integers greater than 0.
The limit configurations (Lower Limit, Upper Limit, Center Line, Sigma) must be either double values or valid fields on the parameter port.
When using the Lower Limit / Upper Limit combination, the Upper Limit must be greater than or equal to the Lower Limit.
The total Number of Sigmas to offset from the center line must be an integer greater than or equal to 1.
If a Sigma / Center Line combination is used, the Sigma must be greater than or equal to 0.

Requirements for data windows

In the case of dynamic ranges on limits, those limits may vary per data point during runtime when calculating over a window.
Regardless of the timestamp on the parameter port limit fields, the latest available limits will be applied to input data; the parameter port timestamp is ignored.
The output timestamp uses the last input data point timestamp used in calculation.

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