I/O Number Assignment Concept - Mitsubishi Q2ACPU User Manual

5. I/O NUMBER ASSIGNMENT
5.2

I/O Number Assignment Concept

When the PLC power is ON or the CPU module is reset, the I/O assignment described
below is performed.
In the sequence program, designate the I/O numbers assigned in accordance with the
following.
(1)
(2)
(3)
(4)
(5)
I/O numbers are sequentially assigned from left to right, taking slot 0 (The slot to the
right of the CPU module) of the main base unit to be "0".
The I/O modules and special function modules mounted to the main base unit occupy
the I/O numbers corresponding to the number of I/O points for each module.
16 points are assigned to the empty slots where no I/O module or special function
module is mounted.
If an extension base unit is connected, its assignment starts from the number
immediately after the number assigned to a main base unit.
The order of assignment for extension base units is not the order in which the
extension base units are connected, but the order of the stage numbers set for the
extension base units. It is possible to connect extension base units as follows: main
base unit 2nd extension base stage
If any extension stage number is skipped, I/O points are assigned with assuming that
"all the skipped stage
1st extension stage.
8 slots" occupy 16 points.
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