Mitsubishi Electric MELSEC Q Series User Manual page 117

(6) "PLC (Empty)" setting
An empty slot can be reserved for future addition of a CPU module.
Select the number of CPU modules including empty slots at No. of PLC and set the type of the slots to be emptied
to "PLC (Empty)" in the I/O assignment screen of PLC parameter.
When using the Universal model QCPU, "PLC (Empty)" can be set between CPU modules.
Therefore, even when the CPU module will be added to the system, CPU No. of a CPU module to be added is not changed,
and changing the program is unnecessary.
CPU
Note that when using either of the following CPU modules, "PLC (Empty)" cannot be set to the left side of the CPU module.
• High Performance model QCPU
• Process CPU
To add the High Performance model QCPU to the system including the PC CPU module/C Controller module, the PC CPU
module/C Controller module must be moved to the right edge.
CPU
Figure 3.14 Addition of the High Performance model QCPU when the PC CPU module is mounted
3 - 12
0 1 2 Slot number
Figure 3.13 "PLC (Empty)" setting between CPU modules
0 1 2 3 4
Addition
Move these modules to the right.
CPU
Set slot 2 to "PLC (empty)".
Keep slot 3 empty.
CPU 0
Slot
number
0 1 2 Slot number
Added Universal model
QCPU
1 2 3 4
Slot
number