Precautions For Creating Operation Output (Step)/Transition Condition Programs - Mitsubishi Electric MELSEC-Q Series Programming Manual

Precautions for creating operation output (step)/transition
condition programs
This section describes the precautions for creating operation output (step) and transition condition programs.
Step program
■Step program expression method
Since a step program cannot use contacts and instructions equivalent to contacts, the operation output of an active step is
executed when the transition condition is satisfied.
Also, a step attribute is used to hold the output or continue operation when the step is activated.
A step program is expressed as a ladder circuit as shown below.
If a program is not created at a step, an error will not occur. In such cases, no processing will occur until the
transition condition immediately following the corresponding step is satisfied.
MELSAP-L program description
The MELSAP-L describes step programs in the following format:
Instruction
Output (o)
High speed timer (h)
Set (s)
Reset (r)
The instructions other than above (o,
h, s, r) are the same as the list.
To arrange several operation outputs in parallel in the same step, separate them with "," (comma).
MELSAP-L format
oY70, sM100, MOV K100 D0
4 SFC PROGRAM CONFIGURATION
68
4.3 Transition
Instruction Example of
MELSAP-L format
oY70
hT0 K100
sM100
rM200
MOV K100 D0
Example of list format
OUT Y70
OUTH T0 K100
SET M100
RST M200
MOV K100 D0
Circuit
Example of circuit symbol