Knowledge Base
Showing results for 
Search instead for 
Did you mean: 

Unable to connect to a G3 ENC or JACE after attempting to commission, downgrade or install a station.


Unable to connect to a G3 ENC or JACE after attempting to downgrade or install a station. One of several different errors may be displayed in the serial shell console output.  The following are examples:

  • Could not find library
  • Could not find library
  • Error occurred during initialization of VM - Java/Lang/ No Class Def found error: Java/Lang/object


I/A Series G3 ENC and JACE (all revisions), ENC-410, ENC-520, TRD-T-645, TRD-T-603, TRD-RB-645, TRD-RB-603, TRD-J-600E, TRD-T-700


The issue is caused by downgrading the ENC / JACE without following the procedure to first install the clean distribution file. In addition, the ENC/JACE will fail if a station is copied into the ENC/JACE without first installing the OS and NRE software using the Workbench Commissioning Wizard.

Note: With G3 release 3.3 and newer, the procedure for downgrading an ENC/JACE is included in the Niagara AX Platform Guide - Downgrading a JACE (Clean Dist).


Tools needed:

  • Null Modem Cable
  • Serial Terminal (e.g. HyperTerminal or TeraTerm)
  • Jumper

Obtaining the files required to recover the ENC

NOTE: If recovery of a Jace-700 is required, please contact Product Support Services for the recovery file.

Download the appropriate OS image and gz file zip file for the ENC/JACE from the Exchange website -           ENC-410-1 standard memory - etfs512    ENC-410-1 extended memory - etfs2048           ENC-520-2 standard memory - etfs512    ENC-520-2 extended memory - etfs2048              JACE-603/645, TRD-RB-603/645, JACE-600E

Note: The files used in the following procedure MUST be the correct match for the ENC/JACE hardware platform otherwise permanent damage to the unit may occur. The serial shell can be used to determine the file system requirements (standard or extended memory).

To find the exact image needed for an ENC (JACE 2/4/5) execute the following while connected to the unit with serial shell:

  1. Log into the unit's menu system using the platform username and password.
  2. Type sh to exit the menu system and enter the shell mode.
  3. At the # prompt, (type: cat sys/info/fs) and enter

This will return the file system type of etfs512 or etfs2048.

Extract the OS image and gz files from the downloaded zip to a suitable directory on the local computer (e.g. local hard drive such as: c:\temp).

Enable ftp:

By default, the ftp port is disabled on every ENC/JACE as shipped from the factory.  Enable the ftp as follows.

  1. Set the jumper on the ENC to serial shell mode and connect the null modem cable between the PC and the ENC/JACE.
  2. Connect to the ENC using the Serial Terminal program and the following port settings:
    • Baud rate 57600 bps (Note: JACE-603/645 baud rate is 115200)
    • 8 data bits,
    • 1 stop bit,
    • no parity
  3. After logging in to the menu system from the serial shell, do the following to enable ftp:
  • Select option 4 from the menu
  • Enter the port number (Normally 21). (type: 21)
  • Press the Enter key to confirm the change

Note: Leave the serial shell connection open while performing the next steps.

FTP the OS image and gz files

  1. On the local system, open a command prompt window and change the directory to the location where the OS image and gz files were extracted (c:\temp).
  2. Connect to the ENC via ftp and put the OS image in the /tmp directory entering the following from the command line:
    • Create a ftp connection to the ENC by typing: ftp and enter
    • Type the username and password for the platform when prompted
    • Change directory to /tmp (type: cd tmp) and enter
    • Change to binary mode (type: bin) and enter
  3. Download the image to the ENC by using the put command. The image name must exactly match the image extracted from the downloaded zip file.
    • ENC-410-1 standard memory (type: put york-etfs512.image) and enter
    • ENC-410-1 extended memory (type: put york-etfs2048.image) and enter
    • ENC-520-1 standard memory (type: put james-etfs512.image) and enter
    • ENC-520-1 extended memory (type: put james-etfs2048.image) and enter
    • JACE-600E, 603, 645 extended memory (type: put npm6xx-etfs2048.image) and enter
  4. Download the gz file to the ENC by using the put command. The name must exactly match the image extracted from the downloaded zip file.
    • Change directory to the root (type: cd ../..) and enter
    • Change directory to /ffs0/zip (type: cd ffs0/zip) and enter
    • Download the gz file (type: put clean.tar.gz) and enter
    • Exit ftp (type: quit) and enter


Execute OS image update

  1. Return to the serial shell connection
  2. Type sh to exit the menu system and enter the shell mode
  3. At the # prompt, type: osupdate and enter
  4. After a short delay the # prompt will return. Shutdown to reboot the ENC (type: shutdown) and press enter.

The ENC/JACE will reboot, install the clean distribution image and perform one additional reboot automatically.  The ENC/JACE should now be recovered and allow connection to the platform.  Connect and use the Workbench Commissioning Wizard to install the version of G3 required.

Tags (1)
Labels (1)
Version history
Revision #:
2 of 2
Last update:
‎2018-09-07 12:12 PM
Updated by: