The NI-DAQ driver ships with Visual Basic examples using NI-DAQ function calls and using ActiveX controls.
While installing NI-DAQ choose to do a custom install and select support for Visual Basic. If you already have NI-DAQ (6.8 or higher) installed you can run the NI-DAQ installer again (setup.exe) and choose to install NI-DAQ. Then choose Add/Remove and from the list you can choose to install support for Visual Basic.
Examples for use with the 6601 can be found in the Counter folder.
Thank you Michael: I installed the 6601 software and hardware. I have tried couple examples written in VB. All examples, I got the same error message at this statement: CWCounter1.Configure Please instruct how do I do? Thank you; Adam