Description:
It allows writing the defined block in the data group (defined on the "
Data" tab) to the
OPC server.
Syntax:
Boolean Write(Long Attr, Long From, Long To)
Parameters:
| Attr | (Long) the way of the transfer: (see OPC DA Basic terms)
0 - asynchronous access (recommended)
2 - synchronous access |
|---|
| From | (Long) Index of the first value (zero-based index). |
|---|
| To | (Long) Index of the last value (zero-based index). -1 = to the end. |
|---|
Return value:
true - on success
false - on error
Note:
Writing to the
OPC server proceeds always into
DEVICE and therefore it is recommended to use the
Attr value 0, i.e. the asynchronous access. When writing to
DEVICE it is necessary to communicate with the device making the
Write method take longer time in synchronous access slowing down the whole appication.
The
Write method
needn't be called if the "
Auto send to server when writing to item" configurator is checked (on the "
Parameters" tab) because the data are then "written" automatically.
Example:
Writing all values to the OPC server:
JavaScriptVBScriptSelect and copy to clipboard
var oOpcGroup = pMe.Pm("/OpcClient/Group1");
if (oOpcGroup.Write(0, 0, -1))
{
// ... on success
}
else
{
// ... on error
}
Dim oOpcGroup
Set oOpcGroup = pMe.Pm("/OpcClient/Group1")
If oOpcGroup.Write(0, 0, -1) Then
' ... on success
Else
' ... on error
End If