Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual page 44

• When inter-module synchronization cycle > motion operation cycle
Example 4
Example 5
Motion operation cycle
• Input refresh is performed when processing the first Motion CPU fixed cycle within the inter-module synchronization cycle. Output refresh is performed when
processing the last Motion CPU fixed cycle within the inter-module synchronization cycle. (Example 4)
• If the Motion CPU fixed-cycle processing time, including output refresh processing, does not end within the motion operation cycle, an operation cycle over is
detected. (Example 5)
CPU module operating status and refresh operation
The CPU module operating status when using the inter-module synchronization function and the I/O (X/Y) refresh operation
are shown below.
CPU operating status
RUN (including when continue error
occurs)
STOP (including when stop error
occurs due to moderate error)
STOP (when major error occurs)
Test mode (including when continue
error occurs)
*1 Refresh is still performed if interrupt is prohibited with a Motion SFC DI instruction.
*2 The Y immediately before going into STOP status is saved, and all devices are turned OFF. Not all modules are turned OFF if there are
modules with allocations as synchronous encoder/manual pulse generator inputs.
Inter-module synchronization processing time
When using the inter-module synchronization function with a Motion CPU, I/O refresh is performed when processing fixed
cycles in the Motion CPU, therefore processing time increases by the increased amount of motion operation time. The
following is a guideline for inter-module synchronization function processing time.
Inter-module synchronization function processing time = 5[s] + 0.7[s]  Number of input points
*1
points
*1 Total number of I/O points (words) for modules that are part of inter-module synchronization and controlled by the Motion CPU
If an operation cycle over condition occurs, review the module subject to synchronization and the inter-module
synchronization cycle settings.
If not using the inter-module synchronization function, by accessing actual I/O (X/Y) at the Motion SFC fixed-
cycle event task, bus access occurs for each instruction, causing a drop in performance.
If using the inter-module synchronization function, an overhead occurs for the amount of processing time
mentioned above, and actual I/O (X/Y) are collectively refreshed, which can reduce motion operation time.
1 MULTIPLE CPU SYSTEM
42
1.3 Data Communication Between CPU Modules in the Multiple CPU System
Inter-module synchronization cycle
Operation cycle over
Refresh
executed/not
executed
Refresh
Do not refresh
Refresh
I/O (X/Y) refresh timing Remarks
*1
Motion operation cycle
• Refresh OFF for Y.
• Refresh is not performed at such times as when the module

*1
Motion operation cycle
: Input refresh
: Output refresh
: Actual input timing
: Actual output timing
*2
does not start up or refresh does not function due to a
parameter error, etc.
*1
+3[s]  Number of output