Intermittent failure on VISA open

[Tim_Gerhardt]

My test software has a problem where intermittently it will fail to open VISA communication to a Keysight N6701C power supply over ethernet. Once the VISA open fails, it remains failing on subsequent attempts but will successfully ping.

Note that it typically succeeds 10 times or more before failing with nothing changed. This is an ESS program so instrument communication opens & closes several times of very long thermal cycles.

The error message is: “Insufficient location information or the device or resource is not present in the system.” 

I have updated the power supply firmware to the latest version.

I am using LabVIEW 2015 & Teststand 2014

The Ethernet connection is through a switch that only connects to the PC and instrumentation.

[Gregory]

Hi Tim,

How do you get it to work again after communication fails?

[crossrulz]

Could you show some code?  I am specifically interested in the VISA Resource string you are providing and the initialization.

[Tim_Gerhardt]

Gregory

Trusted Enthusiast

‎02-11-2020 06:24 PM

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Hi Tim,

How do you get it to work again after communication fails?

Power cycling the power supply.

but this is unacceptable for a test that needs to run unattended for hours.

[Gregory]

Hi Tim,

How do you get it to work again after communication fails?

[Tim_Gerhardt]

Could you show some code?  I am specifically interested in the VISA Resource string you are providing and the initialization.

Here it is. Also, I've verified that the resource string is the same in the failing instances as it is in the successful instances

[billko]

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@Tim_Gerhardt wrote:

Could you show some code?  I am specifically interested in the VISA Resource string you are providing and the initialization.

Here it is. Also, I've verified that the resource string is the same in the failing instances as it is in the successful instances

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When he said "code", he meant "code"!  What can we tell from a picture that doesn't even show the front panel?  Besides, he wanted to see the value of the VISA resource.

Show code, meaning upload the VI.

[Tim_Gerhardt]

Thanks for the help, but I found the problem.

1 power supply rack with 1 ethernet connection testing multiple UUTs in parallel.

I needed to make the power up routine serial so that only 1 thread had the connection open at a time.  (rookie mistake)