PXI chassis not found after host reboot

[bjuberchaub]

I'm running a PXIe-1073 chassis, Win7 and Labview 12.0f3 on the host. After any host reboot, MAX fails to find the chassis and I have to reboot the host. The reboot usually works, but often it is necessary to power down the PXI chassis too. This is all very tedious and time consuming. There must be a way to simply restart the (single) driver and set things right following a host reboot. Thanks for your help!

[crossrulz]

Are you just getting a warning dialog box when you boot up Windows?  If you go into MAX, is the PXI chassis found?

I've ran into a problem where there's a race condition in the drivers.  The error dialog comes up on Windows restart, but MAX shows everything is just fine.

[Chris-NI]

Hi bjuberchaub,

In addition to crossrulz questions, if you're still not seeing your chassis, I'd like to ge the following information:

1. What MXI hardware are you using?
2. What version of PXI platform services do you have installed?
3. When the chassis doesn't show up in MAX, does it show up in Windows Device Manager?
4. Have you made sure you have the latest BIOS version from your computer OEM?
5. Have you been able to reproduce this connected to another host machine?  What about using a different chassis on the same host?

Just to clarify, you first said that the chassis never shows up after any reboot, but then you said a reboot usually fixes the problem.  Do you mean to say that a reboot when the chassis is connected causes it to disconnect, and a reboot when the chassis is disconnected causes it to reconnect?

Regards,

[bjuberchaub]

Thanks for your input. I get no error dialog from windows. Driver race condition sounds right.

To clarify what I wrote above, to put the system in a working state, I have to shutdown the host, reboot the chassis, and (only then) boot the host. If I cycle power on the chassis and try to reconnect, MAX looks fine and I see both of my cards in Windows Device Manager; however, my VIs error out with the message: "MAX timed out while waiting on a driver."

This is with NI-488.2.3.1 and NI-VISA5.2, which I just updated. All software has been updated vi NI updates. The hardware is PXIe1073 with the PCIe (laptop) interface card, PXIe6341, and PXIe6535. 

What was the solution in your case?

[bjuberchaub]

Chris,

Please see reply above for clarification on my reboot sequence and hardware.  The software is all up-to-date.  The BIOS is from Dell.  I will look into whether a BIOS update is available. 

This does appear to be a driver race condition.  Do you have any open bugs of that description?  Is there a workaround short of power-down-host, cycle chassis, power-up-host?

Thanks,

B

[Chris-NI · Accepted solution]

Hi bjuberchaub,

Let's see what crossrulz has to say about the race condition, but the situation you described above does not sound like a driver issue.

Regarding "If I cycle power on the chassis and try to reconnect", we strongly advise against power-cycling your chassis while your computer is on.  This is the equivalent of pulling a PCI(e) card out of a desktop computer while it is running; it can cause permanent damage to your system.

The proper reboot sequence should be:

1. Turn off host
2. Turn off chassis
3. Turn on chassis
4. Turn on host

Never do anything with your chassis power while your computer is on.

Given that:

1. I would be interested in seeing what your Windows Device Manager looks like when the steps above are followed.  Do you see any unknown devices?
2. Is the LINK light on the chassis turned on?  What color is it?
3. Did this setup ever function before without this behavior?

If I misunderstood your comment about power-cycling and you are just following the steps I outlined above, I would be interested in getting answers to questions 1 and 2 when you system is in a non-working state (e.g. you reboot computer without rebooting chassis).

Regards,

[bjuberchaub]

Chris,

This was exactly the information I was looking for. The reboot sequence you stated is implied in the PXIe 1073 user manual but not stated explicitly. It would be a useful addition to that manual.

Your statement that cycling power on the chassis is equivalent to hot swapping a PCIe card seems a bit exaggerated.  Perhaps you could provide the basis for that statement?  It does make sense that power cycling could cause software crashes or hangs, as stated in the user manual.  

Regards,

B

[crossrulz]

The thing is that Windows identifies PCI devices at bootup.  There's a communication that needs to happen.  If the PXI chassis looses power, Windows will no longer be able to talk to the PXI chassis.  Even if the chassis is turned back on, the initial setup communication is not happening because that only happens when the PC is booting up.  It might not actually cause damage, but you are messing up your software configuration when you turn off your PXI chassis.

[bjuberchaub]

Makes sense.  Thx