Mitsubishi MELSEC Q Series Programming Manual page 191

Program Example
The master control instruction can be used in nesting. The different master control regions are
distinguished by nesting (N). Nesting can be performed from N0 to N14.
The use of nesting enables the creation of ladders which successively limit the execution
condition of the program.
A ladder using nesting would appear as shown below:
[Ladder as displayed in the GPP ladder mode]
A
NO M15
B
N1 M16
C
N2 M17
MC N0 M15
NO M15
MC N1 M16
N1 M16
MC N2 M17
N2 M17
MCR N2
MCR N1
MCR N0
[Ladder as it actually operates]
A
MC N0 M15
B
MC N1 M16
C
MC N2 M17
MC,MCR
Executed
when A is ON.
Executed
when A and
B are ON.
Executed
when A, B
and C are ON.
MCR N2
Executed
when A and
B are ON.
MCR N1
Executed
when A is ON.
MCR N0
Not related
to the status
of A, B or C.
5-49
1
2
3
4
5
6
7
8