Concept Of I/O Number Assignment; I/O Number Assignment Of Each Module - Mitsubishi Electric MELSEC Q Series User Manual

3.3 Concept of I/O number assignment

In the multiple CPU system, I/O numbers are used for interactive transmission between a CPU module and the I/O
modules and intelligent function modules, or between CPU modules.

3.3.1 I/O number assignment of each module

The multiple CPU system is different from the Single CPU system in the position (slot) of I/O number 00
However, the concept of the order of allocating I/O numbers, I/O numbers for each slot and empty slots is the same for
both types.
User's Manual (Function Explanation, Program Fundamentals) for the CPU module used
(1) Position of I/O number "00
(a) Slots occupied by CPU modules
The number of slots set with the PLC parameters' multiple CPU settings are occupied by the CPU modules on
the multiple CPU system.
(b) Positions of I/O modules and intelligent function modules
I/O modules and intelligent function modules are mounted from the right of the slots occupied by CPU modules.
(c) When not using the PC CPU module
The I/O number for an I/O module or intelligent function module mounted to the next slot to those occupied by
CPU modules is set as "00
Example: Two CPU modules are mounted
3 - 20
"
H
" and consecutive numbers are then allocated sequentially to the right.
H
CPU 0 1 2 3 4 5
I/O number: 00
Figure 3.19 Position of I/O number "00
Slot number
6 7
H
"
H
H.