The GetOPCValue function is a server function that allows a script to read the value from a tag in the database. A tag is a combination of the address of a database item and the name of one of its properties.
| Syntax |
Server.GetOPCValue (Tag) |
| Description |
The GetOPCValue server function allows a script to read a value from a database item property (referenced by tag). |
| Arguments |
Tag {string} Defines the property and address of the database item that is to be read. |
| Returns |
Value {variant}. Returns the value for the property that is specified by the Tag. This can be integer, string, Boolean and so on. |
Example:
sStateDesc = Server.GetOPCValue (".AI1.AlarmDesc")
MsgBox "The Current Alarm State of this Point is " & sStateDesc
Where:
- sStateDesc is the name of the variable that is used to store the value that is returned by the GetOPCValue function.
- (".AI1.AlarmDesc") tells the script the location of the value that is to be read. In this case, the AlarmDesc value of the 'AI1' point is being read. The tag is a string.
- MsgBox instructs the script to display a Windows message box
- "The Current Alarm State of this Point is " is the pre-defined text string that is shown in the message box
- & sStateDesc instructs the script to add the value stored by the sStateDesc variable to the pre-defined string on the message box. The ampersand & is a VBScript operator.