An event is any noteworthy occurrence in your process or system that you want the system to react to and record. Events that are brought to the operator's attention are alarms. Along with standard alarms and events, the DeltaV system provides the means for users to easily create their own specific alarms and events. Alarms can be applied to any parameter. When that parameter is non-zero, the system can generate an alarm. The event can be logged to the Event Chronicle and optionally brought to the operator's attention as an alarm.
The DeltaV system supports the following means for generating alarms:
Standard alarm detection (PV alarms) is provided in the input and PID function blocks. The alarm limits are configured within the function block. When the alarm condition is detected, the alarm active parameter is set to 1 (for example, the high limit has been exceeded: HI_ACT = 1).
Custom alarms can be applied to any parameter within a control module. When the parameter is non-zero, the alarm is set to active (1).
Fieldbus device alarms are generated by fieldbus devices based on the built-in fieldbus device alerts and PlantWeb alerts when the device alarms are enabled.
HART device alarms are generated by the system based on internal device information. The DeltaV system polls the HART devices and translates the information into DeltaV alarms.
Asset alarms are generated by external, mechanical assets such as turbines, engines, pumps, and motors and by external, optimization assets. Asset alarms are integrated into the DeltaV system through an External Asset Server running on an Application Station.
Hardware alarms are generated in the DeltaV system itself (controllers, workstations, I/O cards, and so on) to alert operations and system maintenance staff to problems so that expeditious actions can be taken to resolve these problems.
The DeltaV Live and DeltaV Operate applications provide special pre-configured displays that show operators the most important active alarms under their control. Active alarm lists can be shown by plant area or unit. With the appropriate security keys, the operator can acknowledge alarms and suppress noisy alarms until the cause can be resolved.
This section refers to alarms generated in function blocks and modules as process alarms because they are typically triggered by a process change. This section also refers to alarms that are derived from a fieldbus or HART device as device alarms and DeltaV system generated alarms as hardware alarms.