How To Suspend a Windows CE Device When a PC Network Card Is Present (246789)


The information in this article applies to:

  • Microsoft Windows CE Platform Builder 2.11
  • Microsoft Windows CE Platform Builder 2.12
This article was previously published under Q246789
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SUMMARY

Windows CE devices do not, by design, enter Suspend mode when a PC network card (PCMCIA) is present in the device. This article describes how to override this behavior.

MORE INFORMATION

To enable a Windows CE device to enter Suspend mode when there is no user input activity (whether or not a connection is open), locate the following registry key: 

HKEY_LOCAL_MACHINE\Comm\Cxport

Create or modify the NoIdleTimerReset DWORD value, and then set a non-zero data value.

The Transfer Control Protocol/Internet Protocol (TCP/IP) protocol stack checks for the NoIdleTimerReset value during system initialization, so you must restart the device after you change settings.

Note that the presence of network activity does not prevent the system from entering Suspend mode. When the system returns from Suspend mode, network services are reinitialized. Any connections that existed before the system entered Suspend mode are broken, and if the Dynamic Host Configuration Protocol (DHCP) is in use, a new IP address may be obtained.

If your custom design uses this override option and also needs to suspend to preserve battery life, you must monitor the idle timing and call the GwesPowerOffSystem function when it is safe to suspend.
Modification Type:MinorLast Reviewed:8/30/2004
Keywords:kbhowto KB246789
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