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MELSEC-Q
7 FUNCTION
7.20 High Speed Interrupt Function
When an interrupt program is created using the interrupt pointer I49, the QnHCPU can
run a program by making high speed, fixed-cycle interrupts at intervals of 0.2ms to
1.0ms.
And, the QnHCPU improves the I/O response by refreshing the I/O signals and
intelligent function module buffer memories in the parameter-set ranges before and
after the execution of the high speed interrupt program.
High accuracy control, e.g. accurate positioning detection, is available with the PLC
CPU alone.
END
Main routine program
(Scan time 1ms)
Step 0
Interrupt cycle interval: 0.2ms (parameter setting)
I49 interrupt program
Main routine program
Waiting time
High speed interrupt start
X input
Buffer memory read
High speed interrupt program execution
High speed interrupt end
Y output
Buffer memory write
I49 overhead
