Mitsubishi Electric MELSEC Q Series User Manual page 171

(c) Memory configuration of multiple CPU high speed transmission area
The following explains the memory configuration of the multiple CPU high speed transmission area of the CPU
shared memory that is used in the multiple CPU high speed transmission function. (For the CPU shared
memory, refer to Section 4.1.1.)
1) Multiple CPU high speed
transmission area
Figure 4.25 Memory configuration of multiple CPU high speed transmission area
No. Name
Multiple CPU high speed
1)
transmission area
CPU No. n send area
2)
n (n=1 to 4)
3)
User setting area
4)
Auto refresh area
When the COM instruction is used in the sequence program, the auto refresh can be executed automatically at the
execution of the COM instruction.
However, the scan time is prolonged due to the processing time for the auto refresh.
For details of the COM instruction, refer to the following manual.
QCPU Programming Manual (Common Instructions)
(d) Settings required for auto refresh
To perform auto refresh, setting the number of points to be sent from each CPU module and a device for
storing data (device for executing auto refresh) on Multiple CPU settings in PLC parameter is required.
4 - 25
2) CPU No.1 send range
2) CPU No.2 send range
2) CPU No.3 send range
2) CPU No.4 send range
Table4.6 Description of multiple CPU high speed transmission area
• Area for data transmission between each CPU
modules in the Multiple CPU system.
• The area up to 14k word is divided by each CPU
module that constitutes the Multiple CPU system.
• Area to store the send data of the each CPU module.
• Sends the data stored in the send area of the host
CPU to the other CPUs.
• Other CPU send area stores the data received from
the other CPUs.
• Area for data communication with other CPUs using
the multiple CPU area device.
• Can be accessed by the user program using the
multiple CPU area device.
• Area for communicating device data with other CPUs
by the communication using the auto refresh.
Description
3) User setting area
4) Auto refresh area
Size
Setting range Setting unit
0 to 14k words 1k word
0 to 14k words 1k word
0 to 14k words 2 words
0 to 14k words 2 words