Alarms notify people that a predefined set of parameters has been met. Typically, these are “offNormal” or “Fault” parameters that are configured to notify specified recipients about the specified condition and to record the conditions that exist when the monitored point meets these parameters. The “normal” parameters for an individual point are properties that may be set and edited, as desired, by a user with proper access and privileges.
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Alarm
An alarm is used to indicate that some value is not within an appropriate or expected range. For example, the normal operating temperature range of a device may be 70 to 100 degrees F. You can set the “out of range” parameters to generate an “alarm” if the operating temperature exceeds the upper limit or goes below the lower limit of this range.
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Alert
This is an alarm that does not have a “normal” state. For example, a motor may require lubrication after every 400 hours of operation (this is not an “out of range” condition). Using the alarming function in Workbench, you can configure an extension to send an email alert to you when the 400 hours runtime has accumulated on the motor.
Example 4. Alarm examples
The following are examples of possible ways that alarms are used:
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Out of operating range notification (offNormal)
An alarm is most commonly used to indicate that some value is not within an appropriate or expected range. For example, the normal operating temperature range of a device may be 70 to 100 degrees F. You can set the “out of range” parameters to generate an “alarm” if the operating temperature exceeds the upper limit or goes below the lower limit of this range.
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Advisory notification (alert)
You may use an alarm in situations to report on a parameter that does not really have a “normal” state. For example, a motor may require lubrication after every 400 hours of operation (this is not an “out of range” condition). Using the alert function, a system integrator can setup an control point that monitors accumulated device run-time and sends an email alert notification at or before the 400 hours run-time has occurred.
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Device fault notifications (fault)
Some devices may report values that are so far out of range that it is obvious that there is a device or system “fault” that needs attention. For example, if a device with a normal operating temperature of between 70 to 100 degrees reports a temperature of 0 degrees F or 1000 degrees F, then it is probable that there is a device or system fault and that the reported temperature is not the actual temperature at the device. The system engineer or supervisor can set parameters and enable alarms for a separate notification for values that are judged to be “faults” as opposed to simply “out of range”.