Duration Alarm Calculation

The Timed Alarm State uses the Duration Alarm (TIMED_ALARMSTATE) calculation type to monitor a list of CVS configurable alarm bits. This alarm calculation type can only be implemented with the CygNet Enhanced Point Scheme. Whenever the time designated in calcparm2 is reached, the system finds the first time all of the configurable alarm bits listed in calcparm1 were set. If that time meets or exceeds the time specified in calcparm2, the specified alarm bit will be set.

See Understanding the CVS Metadata File for more information about the elements and attributes that define a CygNet Point Scheme.

For more information, see Alarm Calculation Types and Point Status Bits.

Duration Alarm

The number of entries stored for this calculation is specified by the histvaluecount attribute in the CvsMetadata file for a CygNet Enhanced Point Scheme.

The following image shows the area of an Analog Alarm Settings page of a PNT Editor with an enabled Timed Alarm State alarm using the Duration Alarm calculation type:

Calculation Parameters

The calculation parameters for this alarm are user-provided:

• ConfigBits (calcparm1) — Little Endian 15-bit binary string configuration read from left to right (CONFIG1 to CONFIG15).

• Time Interval (sec) (calcparm2) — Length of time that all the configured CONFIG bits in calcparm1 have to be set before the alarm bit is set.

Example

• calcparm1 = 001100000000000
• calcparm2 = 30 seconds

The following excerpt from a sample CvsMetadata file for an Enhanced Point Scheme shows a previously "Unused" configurable status bit now assigned to the "Timed Alarm State" as CONFIG14.

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<StatusBitDefinition bitid="CONFIG14" desc="Timed Alarm State" displayorder="1021" calcorder="16" calctype="TIMED_ALARMSTATE">
    <CalcParameter1 desc="ConfigBits"/>
    <CalcParameter2 desc="Time"/>
</StatusBitDefinition>

In this example, the Timed Alarm State bit (CONFIG14) is set when CONFIG3 (Low Warning) and CONFIG4 (High Warning) bits (configured in calcparm1 = 001100000000000) have both been set for a minimum of 30 seconds (calcparm2 = 30).