Device Contention Errors with Parallel Port Network Cards

 Last reviewed: November 21, 1994
Article ID: Q90926
The information in this article applies to:
  • Microsoft Windows for Workgroups versions 3.1, 3.11

SYMPTOMS

If you use Windows for Workgroups with a network interface card (NIC) that plugs into the parallel port, device contention errors may occur. (Only two supported NICs plug into the parallel port: the Xircom Pocket Ethernet I and II.)

CAUSE

These errors occur because Windows for Workgroups sees the LPT port as being used by two different resources: the network and the printer.

WORKAROUND

To work around this problem, use one of the methods below.

Workaround 1

If you do not need the LPT port for local printing, you can disable the check for device contention by removing the following line in the SYSTEM.INI file: 

   DEVICE=VPD.386
Disabling VPD.386 doesn't affect the ability of Windows for Workgroups to print over the network. However, if you are printing locally, no warning appears and printouts may have garbled characters, or you may experience network communication problems.

Workaround 2

In Control Panel, choose the 386 Enhanced Mode icon. Set the Idle Time for the port in question to zero (0). This turns off VPD trapping for that port.

MORE INFORMATION

For more information about device contention in Windows, query on the following words in the Microsoft Knowledge Base: 

   device contention windows

KBCategory: kbnetwork kb3rdparty kbprb kbhw
KBSubcategory: wfw wfwg
Additional reference words: 3.10 3.11 notebook laptop adapter

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Last reviewed: November 21, 1994
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