Three new Cicode functions allow CitectVBA code to
be called from within Cicode script, and be pre-emptively
multitasked by CitectSCADA.
These calls VbCallOpen(),
VbCallRun(), and VbCallReturn()can be nested to implement the
entire function set with a single line of Cicode.
Note: When using the CiVBA language override in a Command field, the compiler constructs the nested call for you. The same mechanism is used even though it is not self evident. For details, see Using CitectVBA in CitectSCADA Command or Expression fields.
For information on multithreading in CitectVBA, see Multithread Considerations with CitectVBA.
To call a given CitectVBA function or subroutine
from Cicode, use the VbCallOpenfunction. This returns a handle which
can then be used to execute the call by passing it to the
VbCallRunfunction. Upon return from
VbCallRun, you can call the
VbCallReturnfunction to get the return value of
the CitectVBA function called.
The Cicode VbCallOpen()function is used to initiate a call
to the CitectVBA function or subroutine, and returns a handle to
the open function.
<ReturnValue> = VbCallOpen(<FunctName>, <ArgList>)
where:
<ReturnValue> represents the handle to
the opened function.<FunctName> represents the name of the
CitectVBA function or subroutine being called.<ArgList> represents a comma separated
list of arguments to pass to the opened CitectVBA function or
subroutine named in <FunctName>.The Cicode VbCallRun()function is used to execute the
CitectVBA function or subroutine (previously opened with the Cicode
VbCallOpenfunction), and requires
the handle returned from the VbCallOpenfunction call. The VbCallRunfunction provides an opportunity for
the opened CitectVBA function to complete and return a value in the
multi-threaded CitectSCADA
environment. It passes its argument value (of OBJECT data type)
through as its return value upon completion.
<ReturnValue> = VbCallRun(<CallHandle>)
where:
<ReturnValue> represents the handle to
the opened CitectVBA function passed through for the <CallHandle>argument.<CallHandle> represents the handle to the
previously opened CitectVBA function as returned by the Cicode
VbCallOpenfunction.The Cicode VbCallReturn()function is used to obtain the
return value of the completed CitectVBA function (previously opened
with the Cicode VbCallOpenfunction), and requires the handle
returned from the VbCallRunfunction
call.
<ReturnValue> = VbCallReturn(<CallHandle>)
where:
<ReturnValue> represents the value
returned by the completed CitectVBA function (which was previously
opened by the Cicode VbCallOpenfunction). The data type of the
return value is dependent upon the data type of the return value
for the CitectVBA function opened.<CallHandle> represents the handle to the
previously opened CitectVBA function as returned by the Cicode
VbCallRunfunction.Example
FUNCTION
TestCitectVBA()
INT iRet;
STRING sMsg = "Hello";
INT iVal = 123;
iRet = VbCallReturn(VbCallRun(VbCallOpen("CiVBATest", iVal)));
Message("TestCitectVBA Function", "CiVBATest = " +
IntToStr(iRet), 0);
END
Example
Function CiVBATest(Value As Integer) As Integer
CiVBATest = Value * 2
End Function
See Also