Mitsubishi Electric MELSEC iQ-R16MTCPU - Page 47

1 MULTIPLE CPU SYSTEM
1.3 Data Communication Between CPU Modules in the Multiple CPU System
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• Abnormal stop
If a Motion CPU major/moderate error occurs (including cases where settings ensure that Motion CPUs stop at a major/
moderate error at each module), Motion CPU output is turned OFF (there are also cases when output is retained
depending on the parameter settings), and a stop command is issued to the control module. I/O refresh continues even
during a STOP condition. Refer to the User's Manual for each module for details on operation when the module stops
abnormally.
■Operation at RUN (STOP  RUN)
When the Motion CPU is changed from STOP to RUN, the Motion CPU issues an inter-module synchronization start
command to each module at the next inter-module synchronization cycle after STOP to RUN, and begins execution of the
Motion SFC fixed-cycle event task at the next inter-module synchronization cycle.
Please note that if system parameters related to the inter-module synchronization function are rewritten during STOP,
analysis is not performed at STOP to RUN, and therefore the module operates based on parameters before rewriting. The
changed parameters will be valid the next time the Multiple CPU system power supply is turned ON, or when reset.
RUN to STOP
Inter-module synchronization cycle
Motion SFC
normal task
CPU module
Motion operation/
Motion SFC
fixed-cycle event task
Motion operation
Inter-module
synchronization timing
(first stop)
Inter-module
synchronization timing
(second stop)
If a moderate error occurs, motion
operation continues (deceleration stop)
Output modules either hold or clear (stop)
external outputs depending on the specifications
for each module.
Inter-module synchronization cycle
Execution of the program is
stopped when a stop error
occurs.
Output
Output
Hold/
Clear
Dec.
stop
Output module
(Inter-module synchronization
target)
Output module
(Not inter-module synchronization
target)
Output module
(Inter-module
synchronization target)
Output
Output
Output
Input Input
Hold/
Clear
Output module
(Inter-module
synchronization target)
Output module
(Not inter-module
synchronization target)
Hold/
Clear
STOP to RUN
Motion CPU
Motion operation/
Motion SFC fixed-
cycle event task
Motion operation
Inter-module synchronization cycle
Inter-module synchronization
cycle
Main cycle
Inter-module synchronization cycle
Motion SFC
normal task
Motion operation
/Motion SFC fixed-
cycle event task
Motion SFC
normal task
Motion SFC
normal task
[St.1550] PCPU ready
complete (SM500)
OFF
ON
The next operation is performed at the second inter-module synchronization cycle.
•Execution of the Motion SFC fixed cycle event task is started.
The next operation is performed at the first inter-module synchronization cycle.
•An “Inter-module synchronization command” is issued to the control module.
•The Motion SFC fixed-cycle event task is not executed.
Output is resumed in
accordance with the
transition to the RUN status.