Topic 1.2.1 – Overview
About Active Event
ActiveEvent is
an ActiveX control that notifies the event system when an event occurs in
another application, such as a deployed object in your Galaxy. ActiveEvent is
script-based and you can use it in any application that supports a COM-enabled
scripting language to detect an event for that application. COM-enabled
scripting languages include InTouch scripting and Visual Basic.
To enable external event
detection for Historian Server, you must:
- Create an event
tag in Historian Server to store the event occurrence information. Make sure that the detection type is set to External.
- Import the Active Event ActiveX script library
aahActiveEvent.dll into the Galaxy so you will have all methods and properties
available for scripting.
- The Historian Server installation program allows you
to install some of the features of the system
separately. The ActiveEvent feature should be installed where the object
running the Active Event
script is deployed.
- Write a script that notifies the Historian Server event system of the
external event.
Scripting ActiveEvent
Use the
ActiveEvent methods in scripts to connect to a Historian Server and detect an
external event. An external detector is triggered using Historian Server
ActiveEvent control. The ActiveEvent control (which resides on a client
machine) interacts with the event detector (which resides on the server
machine) in order to trigger events externally. The ActiveEvent control
facilitates the remote triggering of events on Historian Server by first
initializing with Historian Server computer name and event tag, and then
calling the Invoke Event Ex() method.
You can script
an ActiveEvent using any scripting language that supports COM. For example, you
could trigger an event from a Visual Basic script.
Add EventTag()
Adds an event tag to the active
event tag list.
|
Method |
AddEventTag(string EventTag) |
|
Parameter |
EventTag Name of the event tag with which the ActiveEvent event detector is associated. ActiveEvent is used with an external type event detector. |
|
Returns Value |
0 = Success 2 = Unable to execute method because ActiveEvent is not initialized 7 = Remote function call failed |
InitializeEx()
Creates a connection to Historian Server.
|
Method |
InitializeEx(string ComputerName) |
|
Parameter |
ComputerName Name of the computer on which Historian Server is running. If you are not connecting to Historian Server over a network, use a blank string ("") for the computer name. Note: You cannot use a Historian Server alias for this parameter. |
|
Returns Value |
0 = Success 1 = Unknown failure 3 = Unable to initialize ActiveEvent 4 = ActiveEvent is already initialized 7 = Remote function call failed 8 = Unable to determine local computer name |
|
Remarks |
Once you have initialized with a Historian Server, use the IsConnected property to determine if the connection was successful. Also, you only need to initialize with the server once. You can invoke an unlimited number of events after initialization has occurred. If you are using InTouch, initialization will not occur unless the ActiveEvent ActiveX control is part of an open window. This limits the use of the InvokeEventEx method within InTouch Application Scripts, Condition Scripts, Data Change Scripts, and so on. When you close an InTouch window, all ActiveX controls are automatically uninstantiated. |
InvokeEventEx()
Triggers the event at the time this method is called.|
Method |
InvokeEventEx(string EventTag) |
|
Parameter |
EventTag Name of the event tag with which the ActiveEvent event detector is associated. ActiveEvent is used with an external type event detector. |
|
Returns Value |
0 = Success 1 = Unknown failure 2 = Unable to execute method because ActiveEvent is not initialized 7 = Remote function call failed |
|
Remarks |
You can invoke an unlimited number of events after you initialize with Historian Server. |
InvokeEventAtTimeEx()
Triggers the event at a specified date/time.|
Method |
InvokeEventAtTimeEx(string TagName, string EventDateTime) |
|
Parameter |
TagName Name of the event tag with which the ActiveEvent event detector is associated. ActiveEvent is used with an external type event detector. EventDateTime Date/time that you want the event triggered. This date is in local time for Historian Server. The event date and time must be formatted as: YYYY-MM-DD hh:mi:ss.mmm |
|
Returns Value |
0 = Success 1 = Unknown failure 2 = Unable to execute method because ActiveEvent is not initialized 5 = Unable to perform date/time conversion due to invalid format 6 = Date/time cannot be a future date 7 = Remote function call failed |
|
Remarks |
You can invoke an unlimited number of events after you initialize with Historian Server. |