I fixed (partially) my problem, I used incorrect driver (because of poor documentation of USB use of ADC-11). However, your hint solved the problem of opening and closing the device. Thanks a lot! It would be VERY nice if Pico will provide a documentation of USBADC11.dll, now you must guess all func...

I have try to use PICO ADC11 USB module in my own Delphi 7 application. The problem is that not even the adc11_open_unit routine doesn't work. The function doesn't return anything, it just hangs and uses most of the pc resources. The module itself work properly with Picoscope, and Windows Device man...