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:
The DeltaV Operate application provides special preconfigured 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.
If you are working in a DeltaV Zones environment there are additional considerations.
In a DeltaV Zones environment there are additional considerations you should be aware of concerning alarms and events. Refer to Inter-Zone Alarms and Events for more information.
The DeltaV system supports the following process alarms:
Standard alarms consist of HIGH-HIGH, HIGH, LOW-LOW, LOW, DEVIATION HIGH, and DEVIATION LOW. Standard alarms are only available in function blocks with built-in alarm state computation.
Custom alarms are supported at the module level (except unit modules and phase logic modules). Custom alarms reference existing parameters or user-defined expressions. A custom alarm can be used as an alarm for the operator or an event to be logged. You customize the alarm by selecting from a set of options.
DeltaV process alarms require alarm calculation and alarm detection.
Calculation - Many DeltaV function blocks include alarm state calculations. Any Boolean parameter can provide the alarm calculation component for a module. This component is the input to alarm detection. You can also create your own alarm state calculations by using function blocks that support expressions (for example, the Calc/Logic and Condition function blocks).
Detection - In order for a module to detect the result of an alarm state calculation, you must associate the result of that calculation with a specific alarm parameter. When the alarm state calculates to the TRUE value, the associated alarm parameter triggers.
For the standard alarms, simply select the function block on the diagram, click the right mouse button, and then click Assign Alarm. The software determines the detection parameters for you. For custom alarms, click the alarm view pane (lower-right window in Control Studio), click the right mouse button, and then click Add. You select the detection parameters for the alarm.
Fieldbus and HART devices can report conditions directly to the DeltaV system. These conditions can range from potential problems such as hardware failures within the device, loop problems, and misconfigured parameters, to proactive reporting of upcoming maintenance needed.
Device condition functionality is dependent on the device. Foundation fieldbus devices support either standard Foundation fieldbus alerts or PlantWeb alerts.
Standard Foundation Fieldbus alerts - Devices report alerts in a single alarm: abnormal. This alarm is based on the standard Block Alarm definition.
PlantWeb alerts - Devices report alerts in one of three alarms: Failed, Maintenance, and Advisory. The most recent, active alert condition is reported for its associated alarm. A device can report multiple alarms (Failed, Maintenance and Advisory) but only one alert condition at a time can drive the alarm. Fieldbus devices that support PlantWeb alerts and the reannunciation feature reannunciate alarms if another associated alert condition occurs for the alarm. For example, an acknowledged Maintenance alarm changes state to unacknowledged if a new Maintenance alert condition occurs.
Device alarms derived from PlantWeb alerts are visible through the DeltaV Operate alarm interface tools such as the alarm banner and the alarm summary object. They are also visible in the DeltaV Explorer. Device alarms can be added to your DeltaV displays as well. They may also provide a recommended action based on alarms.
The Configuring Device Alarms topic provides more information.
Although the alarm interface tools and operator displays give visibility to device alarms, the Diagnostics application remains the primary tool to find the cause of device integrity status problems.
Within DeltaV software, all Foundation Fieldbus devices also have a communications failure (Not Communicating) alarm. This alarm is generated when DeltaV software recognizes that a device is no longer communicating on the H1 segment.
HART devices support either standard HART alarming or PlantWeb alerts:
Standard HART alarming - All HART devices connected to non-remote I/O report standard status information to a set of channel parameters. The DeltaV system assigns this information to three possible alarms: Failed, Maintenance, and Advisory.
PlantWeb alerts - Devices report status and specific diagnostic (command 48) information which the DeltaV system assigns to three possible alarms: Failed, Maintenance, and Advisory. Only the status values are also available as HART channel parameters.
Workstations, logic solvers, and controllers have a variety of conditions that indicate potential integrity problems. When detected, these conditions set OINTEG to BAD on the subsystem where that condition was detected, as well as for that node. This is shown in DeltaV Diagnostics.
When a node is not
communicating, it is shown in
DeltaV Diagnostics as 
The conditions that set OINTEG to BAD and the detection of no communication can also generate DeltaV hardware alarms. For hardware alarms, each condition is defined by the system in either one of the following alarms (or defined to not generate an alarm):
Note Control module conditions that set OINTEG do not generate a hardware alarm.
Certain active conditions can encompass other conditions This is done to reduce the number of conditions being reported. For example, if an I/O card stops communicating to the controller, that alarm condition is reported and any other previously active conditions on that card, such as a bad I/O channel condition, are cleared.
All active hardware conditions for a node are displayed in the Conditions Summary application. Any active condition that should not cause a hardware alarm can be suppressed in this application. Suppressed alarms are also displayed in the Conditions Summary application. The Conditions Summary application can be accessed from either DeltaV Diagnostics and DeltaV Operate (from the hardware alarm list or node faceplate).
Loss of communications is detected by the workstation expecting the communication. When a workstation determines it has lost communications with another node, it sets the COMM_ALM alarm. This alarm is displayed on that workstation. Suppressing the COMM_ALM is only suppressing it on that specific workstation. Therefore, if you suppress a COMM_ALM for a controller on one workstation, the alarm is unchanged on any other workstation.
Enabling DeltaV hardware alarms on a node or suppressing a hardware condition does not impact the OINTEG status or presentation. DeltaV applications such as DeltaV Operate (depending on configuration settings), DeltaV Diagnostics, and DeltaV Explorer present the OINTEG status.
Each node's alarms and events are associated with an area in its properties dialog. The default association is Area_A. As with all alarms, nodes report hardware alarms to all workstations which have their area assigned. Of the nodes assigned, any node detected as having a communication problem will annunciate on that workstation, regardless of the alarm scope of the current DeltaV user.
Alarms on external mechanical assets such as turbines, engines, pumps, and motors and alarms on external optimization assets that are monitored and diagnosed by systems that adhere to the Asset Optimization Architecture can be integrated into the DeltaV system and configured for PlantWeb alerts. External assets report alerts in one of four alarms: Not Communicating, Failed, Maintenance, and Advisory. Asset alarms are visible through the DeltaV Operate alarm interface tools such as the alarm banner and the alarm summary object and through Inspect with InSight. Asset alarms can be added to DeltaV displays. Asset alarms are configured in the DeltaV Explorer. The Configuring Asset Optimization Alarms for PlantWeb Alerts topic provides more information.