Responding to alarms in DeltaV Live

The DeltaV System provides both audible and visible indications when a module (or fieldbus device) goes into an alarm condition. Depending upon the severity of the problem, you might hear an alarm horn or see visual alarm information on graphics such as alarm banners, alarm lists, faceplates, and detail displays. These audible and visual cues persist until you respond to them.

To respond to a single alarm parameter, select the alarm parameter data link or click the Acknowledge Alarm button.

To acknowledge all alarm parameters on the main display, click the Acknowledge Alarm button in an alarm banner.

Note

If a fieldbus device has an active alarm and you must delete or decommission the device, download the device port before deleting or decommissioning the device. If you do not download the port first, the alarm remains after the device has been deleted or decommissioned.

Absolute and deviation alarms

Analog values have two types of alarms: absolute and deviation alarms.

Absolute alarms

An absolute alarm monitors a particular parameter (typically the PV) to determine if it exceeds a specific value known as the "trip point." The trip point is the monitored value at which the alarm becomes active. In DeltaV, absolute alarms can be configured as low low, low, high, and high high. For low low and low alarms, the alarm trips, or becomes active, when the monitored value is less than the alarm trip point. Similarly, for high and high high alarms, the alarm trips when the monitored value is greater than the alarm trip point.

Deviation alarms

A deviation alarm trips, or becomes active, when the value of the difference between the monitored value and the setpoint or reference value exceeds the value of the deviation alarm trip point. When the difference is greater than the trip point, the alarm is a deviation high alarm. When the difference is less than the trip point, the alarm is a deviation low alarm.

Alarm priorities

Each alarm is assigned a priority, which indicates the importance of the alarm. The priority determines the order and color in which alarms appear in an alarm banner or alarm list. The three main alarm priorities are CRITICAL, WARNING, and ADVISORY. A special LOG event is also recorded in the Event Chronicle but does not show up on an alarm banner, alarm list, or contextual display. Alarm priorities have default color settings, but note that these defaults may have been changed by the configuration engineers.

Alarm priority	Alarm color (default setting)
CRITICAL	Red
WARNING	Yellow
ADVISORY	Purple
LOG	Blue

The engineer who configures the alarm determines if a horn sound is associated with a CRITICAL, WARNING, and ADVISORY alarm, and if so, the type of horn sound. For example, a beep and a buzz-type sound are typical horn sounds. LOG events do not have a horn sound.