error -1801

[yaoyao]

Hello, the attachment is my programme. I use it to get waveform from a TDS2012 oscilloscope whose signal source is a square waveform with frequency 1KHz and peak voltage 5V,and the oscilloscope was trigged by the signal source itself. When I start this programme, error -1801 occurs.I don't know how to solve this problem,and look forward to your suggestion.

      Thank you!

       yaoyao

[yaoyao]

I have solved this problem accidently. I checked the programme and found no error,so the problem should lie in the settings of the oscilloscope. But I could not find any doubt when I checked the settings.I had no choice ,then reset the oscilloscope to factory settings.Much to my surprise,the programme worked , but I still don't know why,because when I checked the settings such as the trig and CH1 menu and so on of the oscilloscope again I found no difference. Those who know the real reason please tell me. Thank you!