Mitsubishi Electric MELSEC iQ-R-R00CPU - Processing at Interrupt Program Startup

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1 RUNNING A PROGRAM
1.7 Interrupt Program
Processing at interrupt program startup
The processing shown below is performed when the interrupt program starts.
• Saving/restoring of the file register (R) block number
• Saving/restoring of the index register (Z, LZ)
Saving/restoring of the file register (R) block number
When an interrupt program starts, the block number of the file register (R) of the running program is saved and passed to the
interrupt program. Also, when the interrupt program finishes, the saved block number is restored to the running program.
[CPU Parameter]  [Interrupt Settings]  [Block No. Save/Recovery Setting]
Window
Displayed items
When the block number of the file register (R) is not changed during execution of an interrupt program,
enabling "Not Saved/Recovered" can reduce the startup time and the termination time of the interrupt
program. ( Page 899 Overhead time when executing the interrupt program). To change the block number
of the file register (R) while "Not Saved/Recovered" is enabled, the block number of that file register (R) must
be saved/restored by the program.
Item Description Setting range Default
File Register (R) Block
No.
Sets whether or not the block number of the file register (R) is saved/restored when
an interrupt program is being executed.
•Not Saved/
Recovered
• Save/Recover
Save/Recover