The bad value alarms feature

Select the Bad value alarms Feature to add and configure a Bad Value alarm on an attribute of Boolean, Integer, Float, or Double data type. If enabled, alarms will be triggered when the attribute has bad data value or data quality.

A bad value results from bad data quality. Bad quality can occur when:

• The PLC indicates that quality is bad (for example, if communications with a physical device is lost).

• There is a communications error (for example, an OPC or I/O server failure).

• There is a configuration error (for example, a broken I/O reference).

• An out of range value is recorded.

• A script sets data quality to bad.

You can configure graphic elements to highlight when a bad data quality state occurs, and its underlying cause. See Use quality and status indicators to provide runtime feedback for more information.

You can add a Bad Value alarm Feature to a template or instance. If added to a template attribute, the Bad Value alarm Feature is automatically locked in derived objects. Bad Value alarm Features cannot be added to attribute arrays.

In the Alarm message box, you can browse and select an existing attribute or you can type a text string as an alarm message. This text string appears in the InTouch alarm view.

Specify a Priority for this alarm, a numeric value for the urgency of the alarm. Valid values are 1 through 999, with 1 being the most urgent.

For more information about pre-configuring alarm priorities, see Configure priority ranges for alarm historization, mapping, and shelving .