Mitsubishi MELSEC-Q Series User Manual page 36

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OUTLINE
(4) Multiple CPU system setting
(5) Access range of multiple CPU system
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- 13 1.1 What is multiple CPU system?
For control in the multiple CPU system, it is necessary to set up the "Number of
mounted CPU modules" and the "Control CPU" with PLC parameter for all CPU
modules mounted on the main base unit.
QCPU User's Manual (Function Explanation, Program Fundamentals)
In the multiple CPU system, the access ranges are different between the controlled
module and the non-controlled module.
(a) Controlled module
The multiple CPU system's control CPU can refresh the I/O data of controlled
modules and read/write the buffer memory data of intelligent function modules in
the same way as in a single CPU system.
(b) Non-controlled module
It is possible to access non-controlled modules in the following ways.
• Refreshing the input for I/O modules, I/O composite module and intelligent
function modules
(the PLC parameter's multiple CPU setup is necessary.)
• Reading the intelligent function module's buffer memory.
• Downloading the output data from the output module, the I/O composite
module and the intelligent function modules.
(the PLC parameter's multiple CPU setup is necessary.)
However, it is not possible to access non-controlled modules in the following
ways.
• Outputting data to output modules, I/O composite module and intelligent
function modules.
• Writing data into the intelligent function module's buffer memory.
CPU 0 1 2 3 4
1 2 1 1 1 1
Readable with CPU module 2.
Readable with CPU module 1.
Diagram 1.3 Access to non-controlled module
Slot number
5 6 7
Control CPU setting
2 2 2