For a Summary Alarm Type graphic at Runtime, an acknowledged alarm point in an alarm condition incorrectly triggers another alarm notification if the value of the alarm point changes and is still within the same alarm level. This occurs if in Configuratior, the alarm point is Setup By (in the Setup tab) Current Value, and the states (LoLo, Hi, etc.) are configured to use Tag values (in the Value tab).
For example: Suppose an alarm is set up to use a tag for the Lo value. The SetLoAlarm tag is used to set the Lo value to 10.
At Runtime, when the alarm point has a value of 15, it is in the Normal state. If the value changes to 9, the alarm point is in the Lo state, enters in an alarm condition, and causes a message to appear in the alarm window. After acknowledging the alarm point, the message color changes to the acknowledged color (typically green), with ACK State level appearing in the State column. If the alarm point value changes to 8, the alarm point message incorrectly reappears as an alarm that needs to be acknowledged again, even though it is still in the same acknowledged alarm condition. Because it had been Acknowledged in the Lo state, and is still in the Lo state, the alarm point should not appear as an alarm that needs to be acknowledged again. If a sound had been configured for the alarm point, it will also sound again.
This does not affect Detailed or History Alarm Type graphics.
Opto 22 has resolved this issue.