Mitsubishi Q02CPU

9
- 107
9.13 Convenient Usage of Devices
9.13.1 Global devices and local devices
9
DEVICE EXPLANATION
2) Operation at "SM777 : ON"
3) Precautions
• If SM777 is ON, the local device data is read before the interrupt/fixed
scan execution type program is executed and the local device data is
saved after the execution of the IRET instruction.
Accordingly, scan time increases when an interrupt/fixed scan execution
type program is executed once with the setting of "SM777: ON".
• ON/OFF setting of SM777 is enabled in CPU module units.
Setting in file unit is not enabled.
• If the ON/OFF setting of SM777 is changed while a sequence program is
executed, the control is made according to the information after change.
Remark
For details on SM777, see Appendix 1.
(f) Clearing the Local Device Data
Clear the local device data in either of the following methods.
• The PLC is powered on or the CPU module is reset.
• The CPU module enters into the RUN status from the STOP status.
The local device data cannot be cleared by operating from the GX Developer.
Diagram 9.102 When SM777 is ON
X0
X2
D1
D0
DECP
INCP
END
Occurrence
of interrupt
IRET
I0
Interrupt program
Local devices used by
the file name: ABC
Local devices used by
the file name: DEF
File name: ABC
File name: DEF
(Stand-by type program)
Execution of the
interrupt program
Read/write of the
local devices