SetConnectionAttribute

Long  SetConnectionAttribute (LPCTSTR AttributeName, LPCTSTR AttributeValue);

 

Available (from release):

 

stOCX (V4-02), stPro Automation (V4-02)

 

Return Value:

 

Nonzero if successful otherwise 0.

 

Parameters:

 

Name:

Description:

AttributeName

The name of the Connection attribute that is to be set.

AtrtributeValue

The value that is to be set.  See the following table for details of the possible Attributes and Values.

 

Remarks:

 

Call this function to customize the settings for the default Data Source.

 

Attribute information:

 

The following attributes can be set for the default Data Source:

 

Attribute Name:

Units

Applicability:

Description:

"HISTORY"

Seconds

DA

The length of the cache used to store data.  Once the duration has been exceeded then the oldest data values will be overwritten (i.e. the cache is a circular buffer).

"HISTORY"

 

Months

HDA

The Horizontal Horizon.  This is the maximum amount of history that stPro will display within a Plot Window.  stPro will not request history older than this duration from the HDA OPCServer.

 

Tip:  Reducing this duration increases the size of the time scroll bar relative to the total width of the plot making it easier to use and decreasing the sensitivity of pan operations.

"UPDATERATE"

Milliseconds

DA/HDA

The frequency at which data will be collected.

"CACHE"

"YES"

"NO"

DA

Defines whether the data is read from the DA OPCServer Cache or directly from the underlying Device.

 

Note:  Attributes and Values are NOT case sensitive.