Enhanced Write Filter VIs

LabVIEW 2013 Touch Panel Module Help

Edition Date: June 2013

Part Number: 372507E-01

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Owning Palette: Write Filters VIs

Requires: DSC Module or Touch Panel Module. This topic might not match its corresponding palette in LabVIEW depending on your operating system, licensed product(s), and target.

Use the Enhanced Write Filter (EWF) VIs to protect a volume from modifications.


You can configure EWF to use one of the following modes:

  • Disk mode—Redirects write operations to a disk location.
  • RAM or RAM Reg mode—Redirects write operations to the RAM.

Refer to the MSDN Web site at msdn.microsoft.com to learn more about EWF and the EWF modes.

Note  You cannot use the Enhanced Write Filter VIs and the File-Based Write Filter VIs on the same volume.

The VIs on this palette can return general LabVIEW error codes or specific Windows Embedded Standard error codes.

Palette ObjectDescription
EWF CheckpointCreates a new checkpoint on a volume. The volume must be enabled for enhanced write filter (EWF). This VI is only valid when the volume is in EWF disk mode.
EWF Clear CommandClears the pending command that you set since you last restarted the operating system. This VI clears commands set by the following VIs: EWF Checkpoint VI, EWF Commit Volume VI, EWF Protect Volume VI, and EWF Restore VI. The volume must be enabled for enhanced write filter (EWF).
EWF Commit VolumeCommits changes to a volume.
EWF Enable HORMEnables or disables Hibernate Once Resume Many (HORM) on a volume. The volume must be enabled for enhanced write filter (EWF) in RAM or RAM Reg mode.
EWF Get Config InformationReturns the enhanced write filter (EWF) configuration information of the current operating system. The configuration information includes information such as the EWF volume size, EWF mode, and whether EWF and HORM are enabled.
EWF Protect VolumeEnables or disables enhanced write filter (EWF) on a volume. You must enable EWF on the volume to build an image.
EWF RestoreRestores a volume to the last checkpoint and removes all changes made after that checkpoint. The volume must be enabled for enhanced write filter (EWF).


Refer to the Windows Embedded Enabling Features.lvproj in the labview\examples\TouchPanel\Windows Embedded Enabling Features directory for an example of using the Enhanced Write Filter VIs.


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