Memory Used - Mitsubishi Electric MELSEC iQ-R Series User Manual

Memory used

The following describes the memory configuration of CPU buffer memory to be used for data communication.
CPU buffer memory
Refresh area
Send area of CPU No.1
Refresh area
Send area of CPU No.2
Refresh area
Send area of CPU No.3
Refresh area
Send area of CPU No.4
Refresh area
Memory Communication method
CPU buffer memory Communication by direct access
Refresh area in CPU
buffer memory
Fixed scan Communication by direct access
communication area
Refresh area in the
fixed scan
communication area
*1 Data cannot be read or written by the multiple CPU synchronous interrupt (I45); therefore, data between CPU modules cannot be
assured when communicating data using the fixed scan communication area. Make sure to assure data using methods such as setting
a completion flag in write data.
Data between CPU modules must be communicated by direct access because this product does not support
data communication with CPU buffer memory through refresh.
Description
This area reads/writes data from/to the areas of the
host CPU or another CPU module.
*1
This area reads/writes data from/to the fixed scan
communication area of the host CPU, and is used
when the host CPU area and another CPU module
area transfer the data at the fixed scan
communication intervals.
Accessibility to the fixed scan communication area
depends on the combination between the fixed
scan communication function and the inter-module
synchronization function. (Page 114
Accessibility to the fixed scan communication area)
12.2 Data Communication Between CPU Modules
Area size
512K words fixed
It is possible to change within the
range of 0 to 24K words in total. The
send area as per unit can be set
within the range of 0 to 12K words.
12 BUS ACCESS FUNCTION
12
113