Schneider Electric Processor Adapter - Manual (Page 321)

Configuring an M1 CPU with Concept
870 USE 101 10 V.2 321
Understanding the Number of Segments
Only the First
Segment is
Solved The number of segments specified in the Configuration Overview screen
determines the number of I/O Map drops that you will be able to set up for your
CPU. When you are using Concept 2.2, the default number of segments is 1 in
most CPUs.
This number is adequate for all processor adapters and does not need to be
changed. However, you should only use the second segment for I/OBus I/O
mapping or other subroutines.