A standard VTS application includes a WAP content provider for alarms. VTS’s Alarm Page accepts a plug-in module named WAPAlarms. Normally this is provided in the VTS module WAPAlarms.src, but can be overridden by a plug-in module in another layer.
The default WAPAlarms accepts a plug-in module named WAPAlarmList. This module returns a list of alarms and is called with up to four parameters:
• List number
• Ptr to a variable to receive the number of alarms returned
• [Optional] An area name to filter the list
• [Optional] A tag name (derived from a Tag= parameter)
The default WAPAlarmList uses only the first three parameters. In VTScada, a different module is plugged-in which uses the fourth parameter to filter Station alarms.
The Alarm Page entry on the menu links to a summary page generated by WAPAlarms. The default page is built using the template file alarmsummary.wml and lists the number of Active and the number of Unacknowledged alarms.
The page address is “AlarmPage”. The URL parameters and delivered content are:
|
Parameter |
Action/Content |
Notes |
|
Tag=name |
Specifies a tag name |
An alarm list is filtered to show only alarms belonging to a station or its child tags. |
|
None |
Number of Active alarms Number of Unacknowledged alarms |
If non-zero, each is a hyperlink to display the relevant list |
|
List=n |
Displays a list of alarms |
n is one of the defined Alarm List values i.e. 1 = Active, 2 = Unacknowledged |
|
Area=name |
Specifies an area name |
An alarm list is filtered using the area |
|
Name=name |
Specifies an alarm name |
Used with actions Ack and Detail |
|
Action=verb |
Verb is Ack or Detail |
Displays detail of an alarm, or causes it to be acknowledged |
|
PvLb=string |
Labels the PREV link |
Allows caller to define the return link |
|
PvLk=string |
Specifies target address for PREV link |
String must be encoded |
These parameters may be combined where relevant. For example:
• …AlarmPage?List=2&Area=north%20wing
• …AlarmPage?Name=AL.PT200.1.Hi&Action=Detail