VISA communication with Microwave Analyzer N9915A

[aspone]

Hi Folks,

I am pretty new in LabVIEW programming so I would like a help from you. 

I need to automatize a measurement using the Microwave analyzer N9915A. It is necessary just to set some parameters and do a acquisiton of a trace. My setup: Keysight N9915A connected via micro usb cable + LV2016.

I do not have problems using write functions, but when I try to get the data (using VISA READ block) it happens an error. The instrument says "Error: -420, query UNTERMINATED" and the VI shows timeout error: "Error -1073807339 occurred at VISA Read". Using the Open VISA Test Panel, write and read functions work properly.

Could somenoe help me with this problem? Is there some details I am forgetting regarding to configurations?

[kosist90]

I'd suggest to check the following:

• number of bytes what you try to read (although, most probably, it's not the root cause of the problem, but just to be sure);
• termination charachter, what is used for writing/reading. By default, when you have set up termincation charachter, VISA Read function will read message, if that termination characheter will appear in the message.

But overall, also compare settings what you set up from the VI, and settings what you have in NI MAX test panel. If from NI MAX communication is working, then replicate settings from it to your VI.

Hopefully, it'll help...

[aspone]

Hi kosist90,

About the number of bytes to read, it is set correctly. I am trying to receive from N9915A the data set smaller than 1024 bytes. My reading buffer is set more than that. About the termination character, I have tried different characters, but no sucess. Currently I am using the "line feed".

Something that I'd like to share: Yesterday while using VISA test panel from NI MAX, I observed that it does not matter which termination character I set, the read function always works.

I keep to test other communication configurations, but still with no success ...

Wellington