0: No combination, feedback source 1
1: Sum of feedback sources 1 and 2
1: Difference between feedback sources 1 and 2
3: Average of feedback sources 1 and 2
4: Minimum of feedback sources 1 and 2
5: Maximum of feedback sources 1 and 2
6: Min. negative difference or max. negative
difference among multiple reference values
When calculating the difference between