SystemLink messaging returning unauthorized error

[Mihai]

All I'm trying to do is run the vi's in the Sync Messaging LabVIEW example project. They used to work perfectly fine, this is the first time though I'm trying to use them after deploying the SystemLink 2021 R3 version.

This is happening on two computers, both configured as SystemLink clients, therefore I use the Auto connection option. No issues with the connection, and the listening loops in Host.vi and Client.vi loop for a couple of dozen times, then they both return error -251042: The web server responded with error 401 Unauthorized. This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required.

I have not modified the example vi's, except for displaying the iteration counter on the FP so I can see how soon they stop. And I have already rebooted the server, to no avail.

Does anyone else have the same problem? Any ideas on what could I be doing wrong?

[JoshuaP]

What version of the SystemLink Client and LabVIEW SystemLink Toolkit do you have installed on both PCs? I tried running the same example. I have the Client and Host VIs running on the same PC, but connected to an external SL 2021 R3 server.

I was able to send some data back and forth, then let both run for 9+ minutes (3k send loop iterations and 2k receive loop iterations) and tried again to send data again and it continued to work.

[Mihai]

NIPM does not show any updates as being available, everything is up to date.

My server is on premises, running on a virtual server.

I'm sure it's running fine for most people, yet somehow I need to learn what's not quite right in our setup here.

[JoshuaP]

NIPM will only show updates for patches on the Updates tab. For new major versions, you have to go to the BROWSE PRODUCTS tab and search for the product and select the new version which is a bit annoying.

From the screenshot, you posted it looks like you have the latest LV Toolkit but a slightly older client. I doubt the newer client will fix the issue but could be worth updating to at least match your server and LV toolkit version.

It is also possible that something in your network is closing the socket after some period of time if there is no traffic. You may want to try periodically sending a few characters to see if it prevents the socket from being closed.

[Mihai · Accepted solution]

You are wrong! 😂

Updating my client fixed the issue!

Thank you!

[JoshuaP]

I guess sometimes it is better to be lucky than good. 😉