Hi there. I am trying write code in VB.net language and communicate with Keithley electrometer via GPIB-USB-HS with NI-VISA language.While debugging my vbproj codes, I encounterer the following message; "System.Reflection.TargetInvocationException, COM target does not implement IDispatch.". I wonder what it does mean and how to work it around.
The related statement is "DMM.IO = RM.Open("GPIB0::21::INSTR)". One could communicate with it via NI-MAX. So, I guess the problem probably stems from that I am not familiar with NI-VISA language.
Dim RM As Ivi. Visa.Interop.ResourceManager
Dim DMM As Ivi.Visa.Interop.FormattedIO488
RM = New Ivi.Visa.Interop.ResourceManager
DMM = New Ivi.Visa.Interop.FormattedIO488
DMM.IO = RM.Open("GPIB0::21::INSTR) ' Here is an error generated point!
Thanks in advance for your kind advice.