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VXI forces restart of computer

I have seen on some systems that if you have an open aplication that has a handle, and you shut down the VXI chassis the operating system will hang untill you power back up the chassis. I have a new system that forces a re-boot when the chassis is turned back on.  Is there a patch for this?
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Howdy sage69,

From the information here, I assume that you have a PC that remotely controls a VXI system. Further, an application running on your host PC hangs if you shut down your remote VXI system while your host PC is still on. Do I understand correctly?

If I do understand you correctly, then this is expected behavior. With remotely controlled systems through a MXI-3 (VXI-8340 series) interface, the remote system needs to be powered on before the host PC because of the way PCI bus enumeration works. Similarly, if you shut down the remote system while the PC is on, this could cause problems with any applications actively communicating with any VXI device on the remotely controlled chassis.

With MXI-2 you can power cycle the VXI chassis while the host PC is still powered on, but any applications communicating with a module in the VXI chassis will stop functioning until power finishes cycling.

I hope this helps! Please let us know if this answers your question or if there's anything further we can do to help.
Warm regards,

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I have seen the hang problem with firewire, and I think some installations of windows 2000 with MXI-2. With the hang condition the system will freeze until you turn on the VXI chassis again.  The system that I am having this problem on now is an MXI-2 on a PC with XP and service pack 2 applied.  I think I was just having the hang problem until I ran the Resman Patch.  Unfortunately I need to be able to execute resman from my programs.  Sorry for not posting this info before, I had thought the hang problem was fairly common because I had been seeing this on and off for the last 12 years on several system.  

"With MXI-2 you can power cycle the VXI chassis while the host PC is still powered on, but any applications communicating with a module in the VXI chassis will stop functioning until power finishes cycling."  

 What I see is the PC stops working at all until the power is re-applied to the VXI, Then the software shuts down. This is the hang condition. On the forced shutdown condition if let’s say I have word open and the VXI instrument driver running with word having focus.  At this point if the chassis is shut down I will still have mouse movement, but if I try to save the word doc nothing will happen. Once the VXI driver gets focus I will loose mouse control. Now when the chassis is turned back on the PC screen goes to black and the PC restarts.

I have always perceived the issue as a VISA problem, as the hang issue comes and goes over the years. This is the first system that I have set up with XP and the first system I used the resman patch.  The same VXI driver used on a 2000 system with an older VISA  (one that does not need the resman patch) works fine. On this system if the driver is running and you turn off the VXI the driver tells you that it has lost communication and asks if you want to exit the application. The developer at the root level is using VISA calls and is very good at handling the VISA status returns.  So it seems like VISA is the culprit.



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Howdy sage69,

I assume the resman patch you mention is the same one discussed here? Alternatively, NI-VXI 3.5.1 was released earlier this year that contains the fix for running ResMan outside of MAX. The resman patch you mention was a temporary patch until NI-VXI 3.5.1 released. If possible, you might consider moving to 3.5.1

Going back to your original question--could you clarify what you mean by "VXI instrument driver running" and "VXI driver" as in "VXI driver gets focus?" An exact step-by-step process of how to reproduce the behavior you describe would be most helpful.
Warm regards,

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Thank you 3.5.1 fixed the problem.   As for how the problem is produced you will need CVI and a register based VXI device.


Start by writing a program using a GUI in CVI. Add a timer onto your panel. In the timer read and write to a register on your VXI device.

Power on your system.

Run Resman.

Run your program.

Open notepad, position notepad on top of your CVI panel. Your panel has just lost focus. It will not be trying to communicate to the device until it regains focus.

Shut down VXI chassis.  You should be able to move your mouse around your desk top.

Close notepad. This should bring the CVI panel into focus; it will now try to talk to the device. In a properly working system visa should return an error.  In a hanging system your mouse should be frozen at this time.

Turn on VXI chassis, in most hanging systems visa will now return an error and your mouse will now move. My system would go to a black screen and restart.


NI-VXI 3.5.1 fixed this issue on my system.

Thank you



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