Mitsubishi Electric MELSEC Q Series Programming Manual page 110

3 START-UP PROCEDURES
Program name:
SAFETY1
P252
(6) Statement/note/comment
Line space statement and note can be used only in "Peripheral" type. If they are
used in "PLC" type, the sequence programs cannot be executed correctly and
"Safety observation error (error code: 10) (Sequence program error)" will occur.
In addition, a device comment of each program cannot be held in Motion CPU.
Use only "Global Device Comments" (GX Works2)/"Common Comments" (GX
Developer) as device comments.
(7) Execution order of sequence programs
Up to 10 user safety sequence programs can be registered in Motion CPU and
executed in series. The execution order of more than one programs depends on
the label No. which is described on the head of each program.
Label No.
P252 First (must be set even when there is only one main program.)
P370 to P378 Second to tenth (has higher priority as the number becomes smaller.)
The following shows an execution example of more than one sequence
programs.
Program name:
SAFETY2
P370
END
Execaution order of P252 to P370, P371
POINT
(1) Make sure to set a program label P252 and P370 to P378 on the start of each
program. If the label is not set, sequence programs are not executed.
(2) Do not use program labels P252 and P370 to P378 during a program or as
jump destinations of CJ instruction or CALL instruction.
(3) Label number is common in all registered programs. If the label No. is used
redundantly, the program label which is written later has priority.
Execution priority
Program name:
SAFETY3
P371
END
3 - 27
Program name:
SAFETY4
END
The sequence program cannot be
executed so that there are not a
label of P252 and P370 to P378.
END