Alarm Violation Criteria
The only way for a channel to cause an ALARM is to set its “Alarm Violation Criteria” to define what constitutes an Alarm Violation. When these criteria are met continuously for the entire trip delay period (as reflected in the channel's current reading), the channel transitions into an UNACKNOWLEDGED ALARM state. The channel Alarm Violation Criteria selection depends on the channel type, which in turn is dictated by the SNA address.
Discrete Channels:
- Alarm on 0 Raw value
- Alarm on 1 Raw value
Analog Channels:
- Alarm on High Set Point
- Alarm on Low Set Point
- Alarm on High & Low Set Point
Both discrete and analog channel types can also be set to the following:
- Disabled - channel is completely inactive
- Alarm Never (status report only) - channel will give reports when queried but never cause an alarm
- Alarm on Com Failure Only - like “Alarm Never” but will cause an ALARM if there is a failure of communications for a PLC channel.
Discrete Reporting Formats:
- 0 Reported as "0" (default)
- 0 Reported as "Off"
- 0 Reported as "On"
- 0 Reported as "Open Circuit"
- 0 Reported as "Closed Circuit"
Analog Reporting Formats:
- Signed
- Unsigned (default)
- Hex
- Octal
- Binary
- 24Hr Time - causes the report to be given in terms of military hours and minutes of the day. NOTE: In order to get this kind of time report, the corresponding 16 bit register in the PLC must contain a value obtained by multiplying the hours (0-23) by 100 and then adding the minutes. Example: if the time is 13:45, the register must contain the value 13 x 100 + 45 = 1,345. Then with this channel configured for 24 Hr Time format, the reading will be "Thirteen hundred hours 45 minutes".
- Spell - causes digits to be reported as individual numerals in sequence (e.g. "6 4 5 4 3" rather than "Sixty-four thousand five hundred forty-three")
Note: These last two settings are useful for example when reporting maximum and minimum values and the corresponding time of day that they occurred, as stored in PLC register locations.
The formatting of the analog value in reports is determined by standard floating-point number practices.