Hi foxpro professionals

In my application i want to communicate with an SPS ?
The manufacturer(siemens) offers an activx-control (s7data) to handle this.
With Visual Foxpro some things worked good some don't.
I think that the problem depends on the data-typs ???

Here is an example how to read the variable XXX, which works in Visual Basic:
dim xyz as long
dim xxx as variant
s7data.readvariable "XXX" ,xxx , xyz,0
if xxx = ......
endif

When i try it in foxpro i get an ole-error 0x8002005 Type mismatch
local xyz,xxx
xyz=0
xxx=0
thisform.s7data.readvariable("XXX" ,xxx , xyz,0)

I don't know how to handle datatyps long or variant ????
Any help welcomed

Best regards
Albert