A few use case variations of EWF for a flash-based JACE-NXT are described as follows:
Before commissioning, disable EWF on drive C. This ensures that platform changes that affect Windows, such as TCP/IP changes or Windows user or user group changes, are
written to persistent flash memory. Then after all commissioning, re-enable EWF on drive C. The specific sequence is summarized below:
Using a remote desktop client connection, invoke the second command to Commit changes to C drive and leave unprotected.
Invoke the Reboot command.
Using NiagaraAX Workbench, run the Commissioning Wizard. This typically ends with a system reboot.
Using NiagaraAX Workbench, reconnect and perform any subsequent Platform Administration and/or PlatformServices configuration tasks.
Using a remote desktop client connection, invoke the first command to Commit changes to C drive and leave protected.
Invoke the Reboot command.
For relelated details see Commissioning Wizard. For background details on EWF, see Notes on EWF (Enhanced Write Filter) in Windows XPE.
Before applying Windows security updates (distributed as NxtXpeUpdate files), you must disable EWF on drive C. Then after applying the update(s), re-enable EWF on drive C. The specific sequence is summarized below:
Using a remote desktop client connection, invoke the second command to Commit changes to C drive and leave unprotected.
Invoke the Reboot command.
Apply security updates. If you have more than one update, apply them in the proper sequence. Note that a reboot should occur between update packages.
Invoke the first command to Commit changes to C drive and leave protected.
Invoke the Reboot command.
For related details see About Windows security updates for the JACE-NXT. For background details on EWF, see Notes on EWF (Enhanced Write Filter) in Windows XPE.
An already-commissioned flash-based JACE-NXT may require a minor platform or Windows change that should be persisted in CompactFlash.
An example could be a firewall exception change, or a network settings change (say, hosts file change) performed from a Niagara platform connection.
In this case, the unit is likely operating with EWF enabled for both the drive C and drive E partitions. The specific EWF sequence is summarized below:
First use a remote desktop client connection, and invoke the command to Commit changes to C drive and leave unprotected, but do not explicitly invoke the reboot command from the EWF menu.
Perform the configuration change, using the save mechanism available.
If the platform change automatically ends in a reboot, such as from the platform’s TCP/IP Configuration view, go to step 3
If a reboot does not automatically occur (such as after running optionalLockdown.bat), issue a Reboot command from the EWF menu.
Re-establish a remote desktop connection and invoke the command to Enable protection on C drive - requires reboot.
Invoke the Reboot command.
For more EWF details, see Notes on EWF (Enhanced Write Filter) in Windows XPE.
In this scenario, a flash-based JACE-NXT is considered to have a corrupted C drive, perhaps from a virus. The unit is likely
operating with EWF enabled for both the drive C and drive E partitions. The specific EWF sequence is summarized below:
First use a remote desktop client connection, and invoke the command to Discard changes to C drive and leave protected.
Invoke the Reboot command.
For more EWF details, see Notes on EWF (Enhanced Write Filter) in Windows XPE. Also see the next section, A few notes about virus protection.
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