Downgrading a JACE (Clean Dist)

Although the NiagaraAX Framework has historically provided smooth upgrades between software releases, downgrading from one software release to an earlier release can present compatibility problems. This applies particularly to QNX-based JACEs, as binaries for the (QNX) OS are included in dist files.

However, at times it may be necessary to install an older NiagaraAX release onto a JACE, or to restore a JACE to a known good state. “Clean dist” files became available for this. To downgrade a JACE, or otherwise “wipe it clean to start over,” you can install a clean distribution file.

Installing a clean dist will wipe the file system and install an appropriate version of Niagara platform daemon, resetting the unit to a “near factory state.” If the JACE came with an appliance installed, installing a clean dist will also remove that application. Only the following settings are preserved:

TCP/IP settings
license files
brand.properties
most SSL configuration (if an AX-3.7 or later SSL-configured unit)

All other data is removed from the file system, including station bog files, Px files, modules, etc. Note that if an SSL-configured JACE (AX-3.7 or later), its “private key” information is not backed up. In addition, a clean dist restores the factory-default platform credentials and port (3011).Therefore before installing a clean dist file, make sure to backup station files plus any other modules on the JACE you wish to keep. You should backup (export) certificate keys from a AX-3.7 or later SSL-configured unit, such that if the JACE needed to be replaced (hardware swap-out), you could re-import those keys.Remember, that a “Station Backup” creates a dist file that (when restored) includes the same level of software installed at backup time, so instead of (or in addition to) this type of backup, you may wish to use the Station Copier. For related details, see Station Copier.Note that after installing a clean dist, you must recommission the JACE for NiagaraAX, using the Commissioning Wizard.

Cleaning also deletes the !security folder, which in 2013 update releases (e.g. AX-3.7u1) contains files used for encryption of “client passwords” in any hosted station. If cleaned, any previous station save (config.bog) for that AX-3.7u1 host will have non-working client passwords when re-installed. This happens because an AX-3.7u1 host will generate new (and different) key files when it first initializes. In this case, you will need to re-enter all such passwords (e.g. the Password in the ClientConnection container of a NiagaraStation, or the Password in an OutgoingAccount under the EmailService), to have it work again. For related details in this document, see Security update 1 changes to backup dist usage.

A clean dist file has the suffix “-clean” in its name. A clean dist file for most of the various QNX-based JACE hardware platforms is located under a !\cleanDist folder—apart from other dist files under your software database.

Clean dist files appear listed in the Installer with a “WARNING” in the Description column, as shown for the one highlighted in Figure 24.

Figure 24. Clean dist file shown selected in the Distribution File Installer

Clean dists support re-installation of AX-3.5 or later. Note that newer QNX-based JACEs require a minimum release level of NiagaraAX for installation, because of platform dependencies. For example, a JACE-3E requires build 3.7.105 or later of AX-3.7 (AX-3.7u1), a JACE-6E requires AX-3.6 or later, a JACE-700 requires AX-3.5 or later, and so on.

As for any dist file, only the appropriate one for the currently opened platform will be selectable.

The following procedures describes the downgrade process for a QNX-based JACE from AX-3.7u1 to an earlier release. Note that because station architecture changed in AX-3.7, a second procedure was added about downgrading from AX-3.7u1 to AX-3.6u4 while still maintaining interim station data.

Example JACE downgrade from AX-3.7 to an earlier release

To downgrade a QNX-based JACE from any AX-3.7 build to an earlier release (and install a station compatible with that earlier release):

Before installing a clean dist file, make sure you have backed up the station files plus any other data and modules on the JACE you wish to keep.
Start AX-3.7 Workbench and open a platform connection to the JACE.
Open the Distribution File Installer and click Cleaning button for the !/cleanDist directory.
Select the appropriate clean dist file for the platform and install.

The file system clean will take a few minutes, then the JACE will automatically reboot. Wait for the reboot to complete.
After reboot from a clean dist install, the JACE is using default platform credentials and port (3011).
To re-install the software versions to the JACE:
1. Use a version of Workbench that runs the same software versions that you want on the JACE, and use the platform Commissioning Wizard to install the desired software build. For details, refer to the section “About the Commissioning Wizard” in the JACE NiagaraAX Install & Startup Guide.
2. If you have a backup dist file for the JACE that was made when it had the desired older software versions, use the Distribution File Installer to install it. See the previous section, Restoring a backup dist.

Example JACE downgrade from AX-3.7u1 to AX-3.6u4, maintaining interim station data

This assumes you have not changed the JACE’s station database to add AX-3.7 components. Also, once a station is started in a 2013 update release (such as AX-3.7u1), password storage is changed such that an older NiagaraAX release (e.g. AX-3.6) will be unable to start a saved station (config.bog). A workaround is possible, but all AX-3.6 and AX-3.5 JACEs should be upgraded to 2013 “update 4” releases for security reasons (AX-3.6u4 and AX-3.5u4) anyway—and these releases are password compatible with AX-3.7u1. For background information on this, refer to the NiagaraAX 2013 Security Updates document.

In the case where you have upgraded an existing JACE from AX-3.6 to AX-3.7u1, but for whatever reason now wish to downgrade it back to a lower release level (e.g. AX-3.6u4) and still maintain interim saved station data (e.g. alarms and histories), please note there are special considerations and steps required.

Use AX-3.7u1 Workbench to make a platform connection to the JACE, then use the Station Copier to save its station database to your Workbench PC.
Copy the saved JACE station subfolder from your AX-3.7u1 Niagara !/stations folder to your AX-3.6u4 Niagara !/stations folder.
Perform all remaining steps below using AX-3.6u4 Workbench.
On your Workbench PC, start the AX-3.6u4 platform daemon. For example:

Start->All Programs->Niagara AX 3.6.405->Install Platform Daemon
Use AX-3.6u4 Workbench to open a local (My Host) platform connection.
Start the copied JACE station (locally) on your PC.

You will see error and warning messages, but the station should start.
After the station starts, Save it. Then stop the station.
Continue to use AX-3.6u4 Workbench to open a platform connection to the JACE to be downgraded.
Open the Distribution File Installer and click Cleaning button for the !/cleanDist directory.

Select the appropriate clean dist file for the platform and install. Cleaning wipes the station and all software modules from the JACE. The file system clean will take a few minutes, then the JACE will automatically reboot. Wait for the reboot to complete.
After reboot from a clean dist install, the JACE is using default platform credentials and port (3011).
Reopen a platform connection to the JACE and use the AX-3.6u4 Commissioning Wizard to commission the JACE, selecting to install the newly-saved station.

Station selection in the wizard should pre-select all required software modules, but in the software installation (Select Modules) step you can review and select additional modules if desired.
Review the final step in the Commissioning Wizard and initiate the wizard.

Allow sufficient time for the software install and station startup; then open a station connection to the JACE and perform a checkout.
If necessary, remember to restart the AX-3.7u1 platform daemon (niagarad) on your local Workbench PC, as it will be currently running the AX-3.6u4 platform daemon, from Step 3 above.