Can I Use the Controllers Trigger to Shutdown Windows?

[Blaine]

I am using a PXI-8196 controller with Windows 2000 in a PXI-1031DC chassis. This system is replacing a laptop, which during shutdown (from power switch toggle) will power down Windows prior to removing power from the laptop. The reason this system uses this shutdown procedure is because when LabView hangs the microcontroller (coordinates all the devices) needs a method of shutting down the PXI system that does not simply remove power from the controller and hard disk.

The PXI-8196, however, does not have this power down option (although I am told the next gen. of the controllers will, but I don't have the money to buy an entirely new system). As a work around I am trying to use the controllers external trigger to generate a interrupt (when pulled high) in Windows. This interrupt will run a script that will shutdown Windows prior to an external timing circuit removing power.

Is this possible? If so, what IRQ is the controllers external trigger on?

Any help or other suggestions would be greatly appreciated.

Thanks,

Blaine

[Berto]

Hi Blaine,

I'm sorry, but Windows does not support the PXI Trig line, and there is no way to monitor that.

The one solution could possibly be to have your system running in LabVIEW Real-Time, and have a watchdog timer setup with that.  If you are able to have it running in LabVIEW Real-Time, then that is supported by another group and I can get the information over there.  However, with PXI and Windows 2000, we are unable to do this.

mike

[Berto]

Blaine,

R&D would like to know what exactly you're doing?  Would you mind telling us more about your project?

Some chassis have an inhibit pin on the DB9 connection in the back - but this would shut down your chassis in a harmful way.

Thanks,
mike

[Blaine]

The application is vehicle guidance and control. As part of the vehicle guidance and control system, I currently have a laptop in a sealed container that is running LabView on Windows 2000. It is booted by a microprocessor that monitors an external switch. When the external switch is toggled the microprocessor applies power to the laptop and other devices onboard. The laptop is started by the microprocessor by toggling the power switch on the laptop. The user can then log into the the laptop via a wireless antenna. Two methods of shut down are available:

(1)Using the remote login, the user can shutdown the Labview session and then Windows 2000. After Windows 2000 has shutdown the user toggles the external switch, which causes the microprocessor to remove power from the laptop.

(2)The user can toggle the external switch, which causes the microprocessor to remove power from the laptop.

The first shutdown procedure is normal. The second shutdown procedure is used in case the vehicle goes out of control, which is unfortunately a common occurrence.

In replacing the laptop with the PXI system, the PXI system can be configured with the startup and 1st shutdown procedure by placing a relay in-line with the DC power line. The microprocessor will just toggle the relay. However, the PXI controller alone cannot met the 2nd shutdown procedure because, unlike the laptop, it does not have a built-in graceful shutdown that shuts down Windows 2000 prior to removing power from the system when the power button is toggled. This is the problem that I am trying to work around.

I have been told that the next generation PXI controllers will have this graceful shutdown (common on most laptops) built into the switches, but I do not have the budget to buy another controller. 

I have inherited this vehicle guidance and control system and the PXI system was purchased to increase the computational power of the system. Any help that you could extend would be greatly appreciated.

Thanks, Blaine

[Travis_W]

Blaine,

Unfortunately the chassis/controller you are working with doesn't provide a hardware signal that will take care of this automatically.

There is, however, the option of doing this in software.  You could have a LabVIEW program running on your PXI system that polls the state of a digital line (the line you were thinking about sending to the SMB connector on the controller).  If this line is high, you could call a shutdown command from LabVIEW.  Do any of your PXI modules have Digital I/O lines?  If not, you could use VISA to monitor your parallel port.

Let me know if this solution works for you.  Have a great day!

Regards,
Travis

[Blaine]

Travis,

Thanks for the reply. Unfortunately, the LabView code is already very dense and not modular at all (Disclaimer: I didn't write it.) and I don't think it could handle polling at a rate that would keep the vehicle from a catastrophic event such as a crash. Also, sometimes LabView hangs and having the shutdown process being controlled from LabView would force us to use a hard shutdown.

What do you think of using the Serial port or USB host controller for a system interrupt? I have never done it before and don't know if it would work. If you think it might work, do you know of any code out there that would get me started?

Thanks, Blaine  

[Travis_W]

If you had one of our Digital I/O cards, you could use this example program to get started with interrupts from C.