Chapter 4 Block Reference
FieldPoint FP-3000 User Manual 4-6
©
National Instruments Corporation
Figure 4-1. PID Function Block Application Dialog Box
Alarming
The Fieldbus network supports event notification messages from field
devices like the FP-3000. Fieldbus function blocks use event notification
messages to implement alarms and events. Alarms are used to report
conditions that can either be active or inactive, such as the measured value
of an AI block exceeding an alarm limit. The function block sends an event
notification alarm to the host each time conditions transition between active
and inactive. Events are notifications of one-time events as they are
detected by the field device. An example of an event is the update event that
is reported as a host application or operator modifies configuration
parameters of the device.

Alarm Parameters

Each block contains a fixed set of alarms it can report, such as High Alarm
or Deviation Alarm. The alarm parameter is a record describing the current
state of the alarm or event. It contains a number of parameters the device
uses to reveal the current state of the alarm. Following is a list of the
meaning of each field in an alarm record.