Error Message:

NVS: checksum error in <NVS subsystem> calibration block

Applies to:

• All

Service Information:

The calibration parameters saved on the MPE for the specified subsystem are un-initialized or corrupted. Except when a subsystem has been loaded successfully from the head, default values have been loaded into all the subsystem's active calibration parameters.

Since all subsystems are normally initialized when a recorder is integrated, this error should not occur during normal operation, except possibly during firmware upgrades.

The firmware determines whether a subsystem's parameters are valid or corrupt with a checksum "hidden" at the end of each subsystem's calibration and configuration block. A corrupt checksum is corrected when a subsystem is initialized using "nvs init all|(<subsys> cal|cfg)", or saved using "nvs save all|(<subsys> [cal|cfg])".

If firmware has been downloaded recently, this error could be due to an incomplete upgrade (or downgrade) procedure and can be safely ignored until the upgrade is complete. Note that the "nvs upgrade" command should not be used more than once per upgrade. Therefore, if you are uncertain whether or not the upgrade command has been issued since the download, it is safer not to use it.

If no upgrade is in progress, the cause of the NVS corruption should be determined. Inspect the "Saved" column of the subsystem's calibration parameters:

1. If most or all of the saved values are unreasonable, then the subsystem has likely never been initialized, or it was corrupted by an incomplete firmware upgrade. The following procedure should correct the error.
2. If most or all of the save values appear reasonable, then a more serious cause is possible and the error message should be reported to the responsible firmware programmer. The NVS part on the MPE could be failing, or a firmware bug could be responsible (Green Platesetter version 1.57 had such a bug). The following procedure will correct the error, but it may re-occur.

No matter what the cause of this error, and unless the "nvs upgrade" command can be used safely, the best approach is to restore the subsystem from the most recent NVS dump file. Find the subsystem and enter the parameter values listed there. If the either the "Saved values no different than defaults" or "Unitialized section, defaults always loaded" message appears under the subsystem heading, no values need be entered. In all cases, the subsystem can then be saved with "nvs save <subsys> cal".

Note that if a large number of "checksum error" message(s) are reported after an "fload memory" command has been used to restore NVS, the firmware version used to make the backup file and the current firmware version are possibly incompatible. If a more recent backup file is not available (preferably one made with "nvs dump ..."), the firmware should be downgraded to the version used to make the backup file. The firmware can then be upgraded from there following the appropriate upgrade procedure.

Operator Action:

Record error message and contact Creo Service

Cause:

• Firmware upgrade (or downgrade) in progress - should be fixed by "nvs upgrade" command
• NVS never properly initialized
• Version mismatch between current firmware and firmware that created "fload memory" file
• NVS corrupted by firmware bug
• Faulty NVS part on MPE

See Also: