VB.NET
Dim UpperCode, Ret As Integer
UpperCode = 0 ' Invalid
Ret = GpUpperCode(UpperCode)
C
DWORD UpperCode, Ret;
UpperCode = 0; /* Invalid */
Ret = GpUpperCode(UpperCode);
C#
uint UpperCode, Ret;
UpperCode = 0; /* Invalid */
Ret = gpib.UpperCode(UpperCode);
Python
UpperCode, Ret = ctypes.c_ulong(), ctypes.c_ulong()
UpperCode.value = 0 # Invalid
Ret.value = GpibPy.GpUpperCode(UpperCode)