Starting The Interrupt Sequence Program - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

7 APPLICATION FUNCTIONS

7.5 Starting the Interrupt Sequence Program

Main routing
program
I50
Interrupt
program
IRET
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This function checks the interrupt conditions at data receiving from other stations using
the interrupt setting parameters of the host. When the interrupt conditions are matched,
it issues an interrupt request to the CPU module from the network module and starts
the interrupt sequence program of the host's CPU.
[Advantages]
1) The startup of the interrupt sequence program of the applicable station
can be instructed from other stations.
2) The number of programming steps is reduced and the scan time is
shortened because the programming for the startup conditions is not
required in the sequence program.
[Visual representation of the function]
CPU module
FEND
END
POINT
(1) The Basic model QCPU of function version B or later allows the setting of the
interrupt setting parameters.
(2) When multiple interrupt conditions are set, the operation may be delayed if an
interrupt request is issued from other stations at the same time because other
interrupts have to wait to be processed.
(3) When executing the interrupt sequence program, it is necessary to execute
"EI" (Enable Interrupt) with the main routine program.
Network module
Interrupt
condition check
Have the link devices
(LB/LW/LX) changed?
Has the network status
(SB/SW) changed?
Has any channel data
been designated?
.....
ABC SEND
Channel 3
instruction
MELSEC-Q
MELSECNET/H
network
Execute an interrupt
when the conditions
are matched.
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