VTS applications use the Alarm Manager to monitor and manage alarm conditions. Alarms are divided into levels and categories. Levels indicate the priority level of the alarm. Up to sixteen priority levels may be used. These priority levels are numbered from 0 to 15 inclusive. You are free to choose which priority level is to be the highest priority for your application.
The alarm categories define the process or area with which the alarm is associated (for example, some alarms may belong to the same plant or station, while other alarms may be categorized to reflect the equipment process to which they are related). Up to 256 alarm categories may be defined using the AlmCatName statement, numbered from 0 to 255 inclusive.
Alarms are defined using the Alarm statement. Alarm defines the condition that will trigger the alarm, the alarm options, and the alarm message(s). One alarm statement is required for each alarm in the system; it is generally a good policy to keep alarms in a separate module, or possibly in several separate modules.
The physical characteristics of the alarm can be modified using the AlmColor and AlmTone statements. These allow you to modify the colors displayed for each alarm message type, and the pitch and duration of the tone used for the alarm.
The AlmAck, AlmAckID, and AlmEnable functions allow you to acknowledge, enable, or disable an alarm, strictly by specifying its location in one of the alarm lists.
The AlarmCat function returns the alarm category number of a specific alarm instance, and the AlarmInst function returns the instance itself. AlarmCat and AlarmInst are for any alarm specified by its position in one of the three alarm lists. The NumAlarm function returns the number of alarms within a specified range of levels and categories for one of the three alarm lists.
Popup dialogs may be configured to provide an extra level of notification to the operator when an alarm is activated. These dialogs display the name of all active and un-acknowledged alarms, provided that two conditions have been met for the popup to display: the Allow Popups checkbox must be selected on the alarm and the config.ini variable AlarmPopupsEnable must be set to 1.
Alarm Popups, if over-used, can potentially cause more annoyance than assistance to the operator. You should reserve this feature for only the most critical of alarms.
If the alarm popup dialog is closed, the alarms which had been shown in it will not be re-displayed until they go back to normal and then are activated again. The dialog shows only new alarms since it was last dismissed – it is not simply another list of active alarms.
Finally, the AlmList statement enables you to display an alarm list on the screen. Any number of alarm lists may be displayed at once. The area of the screen to use, the number of alarms to display, the list to use, and the amount of information for each alarm can be specified. If a data array is more appropriate for your needs, the AlmArray function may be used instead.
All of the following functions are Plug-in modules, which may be replaced in the application's document file. (Information on the content of the AppMod.src root file can be found in AppMod.src Root File for a Standard Application).