This value will increment by 1 or more for each config change. It persists across reboots. This variable can only be SET with the same value that it currently contains. Any other value will cause a SET-FAILED. Note that this is NOT a TEST-AND-INCREMENT semaphore, as this value does not immediately increment after a config change, but only after a short, though non-zero, delay. Because of this non-zero delay, it is not suitable as a semaphore. Note also that this value counts the number of times that Flash memory has been written, which may be greater than the number of config changes.