Preparing to Upgrade Existing AX JACE Platforms to Niagara 4 - Download Migration Checker (HERE)

Preparing to Upgrade Existing AX JACE Platforms to Niagara 4


The following portion of the AX to N4 Migration Guide focuses on preparing a site to upgrade existing JACE platforms from Niagara AX to Niagara 4.

NOTE: A special BOG file with an AX-compatible Program component is attached to this article.

JACE platform resource requirements

N4 requires more disk space, more Java heap, and more system RAM to run than a similar AX station. Therefore, an AX-3.8 JACE running near capacity will probably not fit the same station when converted to N4. A brief summary of reasons why are as follows:
  • Disk space (Flash)

N4 requires between 14-16 MB more space than an equivalent AX installation. Additional space is required by the new Java 8 VM (vs. Java 5), and new UX features enabling a rich browser experience.

  • Heap space

For an equivalent station, N4 requires more Java heap due to new features and functionality. The baseline heap increase is about 13MB. Additionally, there is an increase in the system memory required to run N4 on a JACE controller.

  • History RAM disk size (NPM6/NPM6E only)

The maximum history RAM disk size on a JACE-6 has been reduced from 64MB to 32MB to free additional system memory. The default RAM disk size is 32MB, so this should not affect most units. If the RAM disk on an AX JACE-6 has been increased, then this increase in the RAM disk size comes at the expense of Java heap. Note that maximum history count has not changed.

See the following sections for more details.


Recommended minimum resources by JACE controller type

The following table summarizes recommended resource requirements in AX, before converting to N4.

Table 1. Recommended JACE resource requirements in AX, before conversion to N4


JACE type/model Minimum Free Disk Space, in MB Java Max Heap, in MB Minimum Free Heap, in MB
(if maxHeap feature is licensed)
NPM3 (JACE-3E) 22 94 38
94 38
NPM6E (JACE-6E, JACE- 603, JACE-645) 24 94 38
JACE-7 22 94 90
(1) If an AX JACE is NOT currently licensed with the “maxHeap” feature, then heap usage will not be an issue in N4.

The Minimum Free Disk Space recommendation is based on the following:

  • 4MB free reserve for future N4 expansion
  • 4MB for Data Recovery (NPM3 and NPM6E)
  • 14MB for N4 increase
  • 2MB for JACE-6 boot partition increase
The Minimum Free Heap recommendation is based on the following:
(20% total 86 NB heap size = 17MB) + (13MB additional N4 overhead + 8 MB smaller heap (J3/J6 only) = 38 MB

Checking AX JACE for N4 minimum resource requirements

There is a special BOG file (attached to this article) with an AX-compatible Program component that you can use to determine if a JACE station meets the minimum resource requirements for and upgrade (conversion to) N4. When copied into an AX-3.8 JACE station and executed, the Program produces a popup notification to state if the JACE station has adequate available resources. Test results are provided for free disk space, free heap memory, and ram disk size.

Figure 1      Example resources check notification using the Program in a AX-3.8 JACE station

Alternatively, you can manually check resources, and compare to the recommended resource minimums given.

Using the N4 resource checker Program

Prerequisite: You have the BOG file with the AX-compatible Program, AX-3.8 Workbench, and can open a station connection (Fox or Foxs) to the AX-3.8 JACE controller.
  1. Copy the BOG file with Program component under your Niagara AX-3.8 system home folder.
  2. Using AX-3.8 Workbench, open the AX-3.8 JACE station (Fox or Foxs), and expand Config to find a folder to copy the Program into, or else add a new folder. You can locate it anywhere under Config.
  3. In the Nav tree, locate the BOG file with Program (may be named “N4UpgradeResourceCheck- erV1_n”) and copy it into the JACE station. You should be able to immediately use the Program.
  4. Right-click the Program in the JACE station, and select Actions→ →Execute. After a few seconds, a popup AX to N4 Upgrade Resource Checker dialog displays the test re- sults, as either “Passed” or “Failed”.
  5. Click OK to close the popup dialog.

Manually checking free disk space in AX JACE

Prerequisite: JACE platform is at AX-3.8 and running the station to be migrated to N4.0.
  1. Using AX-3.8 Workbench, open the station (Fox/Foxs), and expand Config > Services > Platform- Services. Double-click it for the Platform Service Container Plugin view.
  2. In the “Filesystem” entry for /ffs0, look at the “Free” value and compare to the value in Table 2. The JACE value should be equal or greater than this minimum value.

Manually checking heap usage in AX JACE

Prerequisite: JACE platform is at AX-3.8 and running the station to be migrated to N4.0.
  1. Using AX-3.8 Workbench, open the station (Fox/Foxs), and access the Spy page (in Nav tree, right-click Station node and select Spy).
  2. Click util gc
  3. Refresh the page several times, observing the usedMemoryvalue under the After GC” heading.
This represents the low point of Java heap usage.