Aclara SGM1400 Series, User Manual

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S G M 1 4 0 0 S e r i e s S m a r t M e t e r U s e r M a n u a l – S M E T S 2
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Chapter 3 • Physical Components
All defects and enhancements are tracked and documented through the Aclara
SCM system.
The customer release notes will include the following information:
• Description of all changes, listed by ID
• Compatibility information for firmware versions across the solution (e.g.,
electricity meter, gas meter, and in-home displays (IHDs)) including details
on supported firmware upgrade paths
• Known issues and other relevant information
Firmware Upgrade
The SGM1400-B Series meters support application firmware upgrades through
the local communication port and through the AMI communication interface. The
metrology firmware cannot be upgraded. The meter supports firmware upgrades
via DLMS/COSEM and follows WELMEC guidelines.
All metering components that are capable of firmware upgrades will have the
ability to do so remotely and independently of each other, activating a new image
immediately or at a future date.
In the event of a failure to upgrade, the firmware will revert to the previous
version automatically.
Following a firmware upgrade, the meter will:
• automatically restart without the need for a site visit,
• confirm the status to the headend system at configurable points throughout
the process, and
• confirm correct operation to the headend system.
Firmware Security
In order to maintain integrity and assurance of the firmware, Aclara
cryptographically signs the firmware image with an Aclara-controlled private key
as part of the Aclara release process and configuration management.
Prior to image activation, the system will perform a signature validation to ensure
the firmware image to be activated has not been tampered with.
If the cryptographic signature fails to verify, the meter reverts to the last verified
firmware (held in the actively running bank), and the new firmware will not be
allowed to boot into the off-line bank.
After power returns to the meter, the bootloader, which is kept in immutable user
boot flash space, will also perform a cryptographic signature check of the image.
If it matches, the bootloader will continue to boot that image. If it fails, the
bootloader will perform a cryptographic signature check of the off-line image in
order to revert back to it.