Opc data Access Automation Specification

4.4.5.2

 

SyncWrite 

Description 

Writes values to one or more items in a group. The function runs to completion. The values are 

written to the DEVICE. That is, the function should not return until it verifies that the device has 

actually accepted (or rejected) the data. 

Syntax 

SyncWrite(NumItems As Long, ServerHandles() As Long, Values() As Variant, ByRef Errors() 

As Long) 

 

Part Description 

NumItems 

Number of items to be written 

ServerHandles 

Array of server item handles for the items to be written 

Values 

Array of values. 

Errors 

Array of Long’s indicating the success of the individual item writes.. 

 

Remarks 

Writes are not affected by the ACTIVE state of the group or item. 

Example Private 

Sub 

WriteButton_Click() 

Dim Source As Integer 

Dim NumItems As Long  

Dim ServerIndex As Long  

Dim ServerHandles() As Long  

54 

 

---

OPC Data Access Automation Specification2.02 

Dim Values() As Variant  

Dim Errors() As Long  

NumItems = 10 

For ServerIndex = 1 to NumItems 

‘ set up which items to be written 

ServerHandles(ServerIndex) = AnOPCItemServerHandles(ServerIndex) 

Values(ServerIndex) = ServerIndex * 2 ‘ any random value for this example would suffice 

Next ServerIndex 

OneGroup.SyncWrite NumItems, ServerHandles, Values, Errors 

For ServerIndex = 1 to NumItems 

‘ process the Errors 

TextBox(ServerIndex).Text = Errors(ServerIndex) 

Next ServerIndex 

End Sub