have you managed to implement your problem using Gerd's and Bob's suggestions yet?
You can find information about MAX and using the VISA test panel to test instrument control here:
What Is Measurement & Automation Explorer (MAX)?
Sending Hexadecimal Commands in a VISA Test Panel
If you post your VI, we might be able to give you advice on how to implement the task you're trying to accomplish.
Dear Bob Schor,
Thanks for your reply. Sorry for so much questioning. Actually i don't know about MAX. I am a new user of labview.
I see you are running LabVIEW 2014 (I can tell from the VI you attached on your first Post, one of the reasons it is important to post VIs, not pictures of code). If you look on the Desktop of the PC running LabVIEW, you should see the Icon for NI MAX, which looks like this:
This is the Measurement and Automation eXplorer, which can connect to your hardware, allow you to configure it, and allow you to send it commands to do things (so you can test out command sequences, turn Digital Outputs on and off, sample data on Analog Inputs, etc.).
Are you communicating with a single device, or talking to two devices?
If you are talking to a single device, then you should only have one VISA reference control.
Right now you have two and one is set for Com10 and the other is set for nothing by default.
Sorry, the second control was offscreen.
Both were set for Com10. So that seems like you are talking to a single device. In which case you should use a single VISA Com reference. You can't have two sets of code wired up in parallel. It is likely you'll send command A, then send command B and you'll have no control over which VISA read gets which response.
Make sure things are wired up in series with respect to the purple wire and the error wire and you shouldn't have a problem.