Boot from Inactive Partition Image - PCMM2G

The PCMM2G controller contains two versions of the firmware stored in the non-volatile storage (flash memory).

Operational Image

This is the firmware version that was last downloaded is stored in the primary partition.

Fallback Image

This is the firmware version downloaded prior to that is stored in the inactive partition.

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• See Booting the PCMM2G Controller about the partitions in the PCMM2G non-volatile storage.

Boot Failure

In rare situations, the controller might be unable to boot into operational firmware.

Examples: A failure could be caused by:

• Corruption of the flash memory containing the firmware image.
• A critical error early in the boot process.

Although Kollmorgen tries to ensure these failures never happen, the possibility requires a recovery mechanism to allow a working firmware image to be programmed.

Fallback Mode

Drastic failures of the operational firmware (i.e., those that cause the firmware to crash) trigger an automatic reboot into the fallback firmware image.

• An automatic reboot into the Fallback Mode does not happen when a critical error occurs early in the boot sequence.
  • This is a rare occurrence.
• The 7-segment display is stuck showing either 2 or 3.
  • It is possible for users to explicitly boot the controller into the Fallback Mode.

Boot into Fallback Mode

To explicitly boot into Fallback Mode, press and hold B3 button when powering up the controller.

• The goal of running a Fallback image is to recover the controller by downloading working operational firmware.
• The 7-segment display on the controller reports an E60 () error when the controller has booted up in Fallback Mode.

Limitations

There are some limitations to the system when the controller is running from the Inactive partition.

• The auto-start option for the KAS application is not supported.
  • The user must start the KAS application manually every time after the controller is powered up.
• An E60 error is reported to indicate the active partition is corrupted.
  • This error is cleared when a new firmware is downloaded or restored using the previously taken controller backup.
  • See either the Firmware tab or Restore tab.

Notes

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• It is strongly recommended to upgrade firmware again to have the same firmware version on the Active and Inactive partitions.

The KAS application remains compatible when the controller is operating with the same firmware version on the Active and Inactive partition.

• If the Active partition becomes corrupted, the controller runs from the Inactive partition.
  • If the firmware is the same on the Active and Inactive partitions, the KAS application runs correctly.
    • This avoids the need for the users to compile and download the KAS application to keep the machine running.
    • The user has time to download new firmware for resolving the corruption in the Active partition.
  • If the firmware is not the same on the Active and Inactive partitions, the KAS application does not work.
    • Failure Correction: On the Inactive partition, download and compile the firmware that is on the Active partition.

Recovery Mode

In the rare event the Fallback image stored in the flash memory does not work either, the controller can boot into Recovery Mode using the USB flash drive.

A binary image that boots the controller from the USB flash drive is provided with the firmware release.

See PCMM2G Web server Recovery about how to recover the controller from the USB flash drive.