UT_ANNUNCIATOR — Alarm group: horn, lamp, first-out, ack / silence / test

Drives a panel horn and alarm lamp (or beacon) for a group of
UT_ALARMs. It follows the standard annunciator sequence: a new
alarm gives a fast flash plus the horn; after acknowledge the lamp goes steady;
an alarm cleared but not acknowledged gives a slow flash. It also identifies which
alarm came first.

Pins

Record UT_ANNUN_DATA

How it works

• Horn: sounds for each new alarm at or above hornPriority, until Ack,
  Silence, hornTimeout, or until nothing at that priority is left to acknowledge
  (e.g. acknowledged one by one on the HMI). A new alarm after a silence sounds it again.
• Ack writes cmdAck into every unacknowledged alarm in the group; each alarm
  acknowledges itself on its next call. The horn stops at once.
• First-out: the event starts when the first alarm appears in a quiet group. The
  alarm with the earliest sequence is the first-out (alarms raised in the same
  millisecond: the lowest index). It stays until the event is over, i.e. no alarm is
  present or waiting for acknowledgement.
• Shelved, suppressed and out-of-service alarms are ignored completely.
• A flash shorter than the PLC scan can't be shown: the lamp then changes every scan.
• A command held on acts only once.
• An empty group is fine: everything stays off.

Using it

VAR  PumpAlarms : ARRAY[1..3] OF UT_ALARM_DATA;  END_VAR

A1(In := P1Fault, Data := PumpAlarms[1]);
A2(In := P2Fault, Data := PumpAlarms[2]);
A3(In := HighLevel, Data := PumpAlarms[3]);
Panel(Ack := AckPB, Silence := SilencePB, LampTest := TestPB, Alarms := PumpAlarms, Data := PanelCfg);
Siren := Panel.Horn;
Beacon := Panel.Lamp;