Mitsubishi Electric MELSEC iQ-R C R12CCPU-V User Manual page 173

Usage
1.
Register a multiple CPU synchronous interrupt program (I45) on the interrupt routine. (Page 46 Interrupt Function to
C Controller Module)
2.
Enable the registered interrupt routine. (Page 46 Interrupt Function to C Controller Module)
3.
Configure the refresh settings. (Page 155 Setting refresh area)
Interrupt timing
The multiple CPU synchronous interrupt program (I45) is executed at the timing for the cycle of the fixed cycle
communication. The cycle of the fixed cycle communication can be changed in "Fixed Scan Communication
Setting".(Page 158 Fixed scan communication setting)
Considerations
The following shows the considerations for the multiple CPU synchronous interrupt program.
• Do not create a multiple CPU synchronous interrupt program of which execution processing time is longer than the cycle of
the fixed cycle communication. If so, the multiple CPU synchronous interrupt interval cannot be guaranteed. For a multiple
CPU synchronous interrupt program (I45), the settings for the execution time monitoring and the operation at the time of
excess can be configured by "RAS Setting" of CPU parameter. (Page 64 Error detection setting, Page 65 Operation
setting when an error is detected)
• To ensure the data transmission at the following cycle of the fixed cycle communication, set "Program Execution Section
Exceed (I45)" to "Detect" in the RAS setting of the CPU parameter. An error can be detected if data have been written at
the timing when data cannot be sent in the cycle of the fixed cycle communication.
Fixed scan communication cycle
Multiple CPU
synchronous interrupt
program of the CPU
No.1
Multiple CPU
synchronous interrupt
program of the CPU
No.2
Send data (A) of
CPU No.2 is written
Send data of CPU No.2
Data is sent at the next scan
because it has been written
before data communication.
Fixed scan communication cycle
Send data (A) of CPU No.2 is
received at the next scan.
Send data (B) of
CPU No.2 is written
Data communication
section by system
Data is sent after two scans
because it has been written
before data communication.
Send data (B) of CPU No.2 is
received after two scans.
8 MULTIPLE CPU SYSTEM FUNCTIONS
8.4 Data Communication Between CPU Modules
8
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