invoke hp605x_32.dll error---- parameter 2 is invaild

[cat099]

hi All,

      i have downloaded the vixpnp driver for hp6050(electronic load) from ni driver network.But have a strange thing.

      i wrote the code with c#,and create the .cs file for hp6050 with ni measurement studio.

     "hp605x DCLOAD = new hp605x("GPIB0::8::INSTR", true, true);"

when i execute the load self_test,the instrument work fine.

    int result;
            StringBuilder test_message = new StringBuilder();
           int a=DCLOAD.self_test(out result, test_message);
           if (a==0)
           {
               MessageBox.Show("ok");
           }

and set_channel is same

but when i execute the function for measure the current of the load,there is a error message ("parameter 2 is invaild")

int measurement_type=0;
            double measurement=0.0;
            DCLOAD.setChannel(2);
            DCLOAD.measure(measurement_type,out measurement);
          
                MessageBox.Show(measurement.ToString());

what is wrong?everyone,Can you give any advice for it?

thanks a lot.

[cat099]

no respond?