Conditions

Current Value Compared to Fixed Value

In this example, an alarm will occur if the current value of the tag is >= 6:

Current Value Compared to Value of Another Tag

In this example, an alarm will occur if the current value of the tag is >= the current value of the Site 1/battery/1/Battery State of Charge tag:

Max Change Over a Time Interval Compared to Fixed Value

In this example, an alarm will occur if the absolute difference between the minimum and maximum value in the past hour is >= 10:

Max Change Over a Time Interval Compare to Value of Another Tag

In this example, an alarm will occur if the absolute difference between the minimum and maximum value in the past hour is >= the value of the Site 1/battery/1/Battery State of Charge tag:

Tag is Unavailable for Amount of Time

In this example, the alarm will occur if the tag is not available (NA, in other words has no value) for 30 minutes straight:

Bit Value

In this example, the alarm will occur if bit 12 (1 << 12 or 0x1000) of the tag is 1. Only bits 0-31 of 32-bit integer values are supported (non-integer number values are ignored):

Bit Field Alarms

In this example, the alarm will occur if bit 12 (1 << 12 or 0x1000) of the tag is 1, but unlike the above example, this alarm is provided by the Inverter Status Bit Field Type that is assigned to the tag in the Tag Settings form. In this case, the Severity, Bit, Active When 0/1, and Message can't be changed here; they can only be changed by editing the bit field type (which will also affect alarms for all other tags with that bit field type).

Custom Formulae

In this mode you can enter arbitrary conditions. All of the above conditions can be expressed as a custom formula, and when you switch to Custom Formula mode it will show the formula corresponding to the condition you had selected (unless any options were blank). The formula must evaluate to true, false, or null; any time it becomes true, it triggers an alarm event. See Formula Language for a complete guide to writing formulae.