Data Communication With Fixed Scan Communication Area - Mitsubishi Electric MELSEC iQ-R Series User Manual

Data communication with fixed scan communication area

This method writes device data of each CPU to the fixed scan communication area of the host CPU in a cycle set in the fixed
scan communication setting. Device data that is written to the fixed scan communication area is sent to that area of another
CPU module, and then is read by the module.
Data communication flow
Programmable controller CPU (CPU No.1)
CPU buffer memory
Fixed scan communication area of CPU No.1
Fixed scan communication area of CPU No.2
Ò
×
For CPU No.1
For CPU No.2
■Processing contents of the END processing in a programmable controller CPU
: Device data for CPU No.1 is transferred to the refresh area of the fixed scan communication area.
: Device data in the fixed scan communication area of CPU No.1 is sent to CPU No.2.
: Device data stored in the refresh area of the fixed scan communication area is transferred to devices for CPU No.2.
■Processing contents when a function of this product is executed
: Device data in the fixed scan communication area is read to the user program with the mdReceiveEx function or the
mdBdReceiveEx function.
: Device data of the user program is written to the fixed scan communication area with the mdSendEx function or the
mdBdSendEx function.
: Device data in the fixed scan communication area of CPU No.2 is sent to CPU No.1.
12 BUS ACCESS FUNCTION
118
12.2 Data Communication Between CPU Modules
Ó
Refresh area
Refresh area
Device
MELSECWinCPU module (CPU No.2)
CPU buffer memory
Fixed scan communication area of CPU No.1
Ö
Fixed scan communication area of CPU No.2
User program
Execution of the
mdReceiveEx/mdBdReceiveEx function
Execution of the
mdSendEx/mdBdSendEx function
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Õ