Interrupt Settings - Mitsubishi Electric QJ71LP21 Reference Manual

7 APPLICATION FUNCTIONS

7.7 Interrupt Settings

Main routing
program
I50
Interrupt
program
IRET
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The remote master station uses the host interrupt setting parameters to check interrupt
conditions at the time data is being received from the remote I/O station.
When the interrupt conditions are matched, it issues an interrupt request to CPU module
from the master module and starts the interrupt sequence program of the CPU module.
Up to 16 interrupt conditions can be set per network module.
[Advantages]
1) The startup of the interrupt sequence program of the applicable station
can be instructed from remote I/O 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
• 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.
• When executing the interrupt sequence program, it is necessary to execute "EI"
(Enable Interrupt) with the main program.
REMARK
Since the MELSECNET/H does not support the SEND instruction, the device code
RECVS instruction cannot be used.
For details about interrupt settings, refer to the Q-corresponding MELSECNET/H
network system reference manual (PLC to PLC network).
Master module
Interrupt
condition check
Have the link devices
(LB/ LW/ LX) changed?
Has the network status
(SB/ SW) changed?
MELSEC-Q
Master
MELSECNET/ H
network
Execute an interrupt
when the conditions
are matched.
Remote
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