XL2OL
4.33.1
11/16/2015
SCN: 2846 — XL2 Setup Configuration Parameter Values Lost after Power Cycle

If a Setup Configuration was loaded and the controller imediately power-cycled, the setups within the Configuration would revert to their prior values. If any setup was modified prior to the power-cycle, the setups within the Configuration would then be locked in and a power-cycle would have no effect.

This bug has been present since the Setup Configuration feature was added. I think it has not been detected until now because things like Trim Correction would Mask the problem.

Setup Values are stored within a structure that is protected with a checksum so that corruption may be detected. There are two copies, each with a checksum, to ensure we always have a valid copy of setups if power is turned off in the middle of the calculation. When a setup is modified its value is written to copy 1, the copy 1 checksum is calculated and then the entire copy1 structure, including checksum, is copied into copy 2.

The issue was that when a configuration was loaded it was loading the setup values for Configuration Setups into copy 1 but it was not calculating the checksum. On a power-cycle the checksum error was detected and since copy 2 still had a valid checksum, the setups reverted to the values in copy 2.