PCI parallel port with no IRQ assignment

[verycbe]

I have a PCI parallel port connected to my Windows XP 32 bit machine. The parallel port works perfectly. However, it stops working if I allow the machine to idle for sometime. I tried resetting the drivers and disabling the devices. Neither of
them brought back the parallel port. The parallel port is still available but it just won't work.

 I found that there was no interrupt assigned to the parallel port. The parallel port comes back live if you reinsert the parallel port card into the slot or re-start the machine. Could this be associated with the fact that there is no interrupt assigned to the parallel port? In my device manager, there is a question mark next to PCI simple communications controller but the parallel port drivers are properly installed. Any thoughts would be appreciated

[Jan Axelson]

If you mean the port stops working after the PC comes out of sleep or hibernation, you can try changing the settings in Control Panel > Power Options to see if it helps.

If there is a question mark in Device Manager even when the port is working, there was likely a problem in installing the driver. The setupapi log file might offer a clue.

http://support.microsoft.com/kb/927521

Jan

[verycbe]

The PC does not have to hibernate. The parallel port stops communication if you allow the computer to idle for some time (30 minutes to 1 hour). I tried powercfg.exe. The setup on those settings were meant for waking the computer using those devices. It did not help.

The question mark in device manager is not on LPT1 but on PCI simple communications controller. I am not sure whether it has relevance to the fact that there is no interrupt assigned to LPT1.

[verycbe]

I just checked. The PCI simple communications controller error in device manager had nothing to do with the parallel port problem. I verified this by removing the PCI parallel port card and just the parallel port disappeared from the device manager.

The parallel still stops working after some time. The powercfg options in windows allow to wake the computer using the pci devices. There is nothing related to interrupt settings.

[Jan Axelson]

Try disabling Standby and Hiberate in the Control Panel. Even if this isn't want you ultimately want, it will verify (or not) the source of the problem.

Jan

[verycbe]

Thanks for the reply. I rolled back to a previous version of the driver provided by the PCIe card manufacturer. The only improvement is that if the parallel port dies, I am able to bring it back by disabling and re-enabling it.

I am not able to use devcon to disable the device. I must find out a way of controlling the device manager from command prompt or find alternatives in the Windows API. Thanks for all the suggestions.