Mitsubishi Q02CPU

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3.3 Settings for Creation and Execution of Multiple Sequence Programs
3.3.5 Fixed scan execution type program
3
SEQUENCE PROGRAM CONFIGURATION AND
EXECUTION CONDITIONS
(3) Precautions for programming
(a) Device turned ON/OFF by PLS or similar instruction
When using an instruction such as PLS, by which an execution condition turns ON
from OFF in the next step and it turns the operation device ON, the device
remains ON until the same instruction is executed.
When using an instruction such as PLF, by which an execution condition turns
OFF from ON in the next step and it turns the operation device ON, the device
remains ON until the same instruction is executed.
(b) EI/DI instruction
During execution of a fixed scan execution type program, interrupts are disabled
(DI) so that any other interrupt is not enabled.
Do not execute the EI/DI instruction during a fixed scan execution type program
execution.
(c) Timer device
Timers cannot be used in fixed scan execution type programs.
The timers update the current values and turn ON/OFF the contacts when the
OUT T instruction is executed.
Using a timer in a fixed scan execution type program updates the current value
only during execution of the fixed scan execution type program.
Hence, normal measurement cannot be made.
(d) Instructions not available in fixed scan execution type programs
For instruction not available in fixed scan exection type programs, refer to each
instruction of programming manual.
(e) Execution of fixed scan execution type program
Before executing a fixed scan execution type program, it is necessary to enable
interrupts by the EI instruction in the initial execution type program/scan execution
type program.
Diagram 3.47 Device turned ON by PLS instruction in fixed scan execution type program
X0
OFF
ON
M0
OFF
ON
END 0
0
ENDEND 0 END 0 0 END END 0
X0 X0
Fixed scan execution
type program
Turned ON when PLS M0 instruction is executed on
leading edge (OFF ON) of X0.
Turned OFF when PLS M0
instruction is executed.
PLS M0 PLS M0