Instrument Control (GPIB, Serial, VISA, IVI)

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VISA TCP/IP SOCKET session attributes

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I'm attempting to control 2 instruments with VISA TCP/IP SOCKET sessions.

Queries time out with the default settings for both instruments.

In NI MAX I've found that either setting VI_ATTR_SUPPRESS_END_EN to false or setting VI_ATTR_TERMCHAR_EN to true fixes the time out issue.

Unfortunately changing settings in NI MAX doesn't stick/save.


One instrument I control in LabVIEW and so I was able to set the VISA session attributes with a property node and things work.


The second instrument is controlled by other software and can't change from the default settings for VI_ATTR_SUPPRESS_END_EN and VI_ATTR_TERMCHAR_EN.

I can't modify this other control software.


Is there a way to change the default value for VI_ATTR_SUPPRESS_END_EN and/or VI_ATTR_TERMCHAR_EN for VISA TCP/IP SOCKET sessions?

Or, is it possible to change another program's VISA session attributes?


Many thanks,

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Accepted by topic author JR_

The VISA Attribute setting must be changed within the program.
Values that do not change will use the default values as VISA.
I don't think you can change the default value in advance from the outside.

There is no choice but to contact the program author or vendor and ask them to modify the program itself so that the Attribute can be changed by the user.

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Accepted by topic author JR_

I thought that might be the case. Thanks Iwa6 for answering my questions.


In case anyone else has trouble with this:
I tried a different PC and the VI_ATTR_SUPPRESS_END_EN attribute doesn't appear as an option in MAX, queries don't time out and the software works without changes.

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