Read Tag Alarms (Historical, Area) VI

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Updated2024-11-20
5 minute(s) read

Reads alarms for the specified tags, processes, or alarm areas. You must manually select the polymorphic instance to use.

Note This VI interacts with data in the Citadel database only.

Use the pull-down menu to select an instance of this VI.

Inputs/Outputs

database URL —

database URL specifies the computer name and the database name where the Citadel database resides. Enter the database URL in the format \\computer\database.

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Tag Reader in specifies the data of a group of tags that the Open Tag Reader VI opens.

alarm area —

alarm area specifies the alarm group or area in which you want to read alarms. You can specify the alarm area on the Alarming page of the Shared Variable Properties dialog box.

time interval —

time interval specifies the span of time between the start timestamp and stop timestamp. If you do not wire this input, this VI reads all the alarms that are relevant to the specified tag from the Shared Variable Engine (SVE).

start timestamp —

start timestamp specifies the date and time associated with the first alarm that this VI retrieves from the SVE. If you do not wire this input, this VI extracts the alarm starting at the time of the first alarm in the SVE.

stop timestamp (now) —

stop timestamp specifies the date and time associated with the last alarm that this VI retrieves from the SVE. If you do not wire this input, this VI extracts the alarm up to the last alarm available in the SVE.

error in (no error) —

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

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Tag Reader out returns data of the tags that this VI opens.

alarms —

alarms returns the alarm information for the specified shared variables, processes, or alarm areas.

alarm URL —

alarm URL returns the name of the alarm.

set time —

set time returns the time that the alarm occurred.

set user —

set user returns the user who was logged in when the alarm activated.

ack time —

ack time returns the time that the alarm was acknowledged.

ack user —

ack user returns the user who acknowledged the alarm.

clear time —

clear time returns the time that the alarm was cleared.

clear user —

clear user returns the user who cleared the alarm.

setpoint —

setpoint returns the value of the shared variable at the time when the alarm occurred.

value —

value returns the shared variable value when it changes alarm states. The shared variable value updates only when the shared variable changes alarm states and is not necessarily the most recent alarm value.