I/O Relays [X, Y]; Numbers Of I/O Relays; Functions And Roles - Mitsubishi FX3U Series Programming Manual

FX /FX Series Programmable Controllers
3U 3UC
Programming Manual - Basic & Applied Instruction Edition
4.2

I/O Relays [X, Y]

Some numbers of input relays and output relays are specific ones secured in the main unit, and other
numbers are assigned to extension devices in the connection order. Because these numbers are octal,
numeric values such as "8" and "9" do not exist.
4.2.1

Numbers of I/O relays

The table below shows input relays (X) numbers and output relays (Y) numbers (Numbers are assigned in
octagon.)
Model
name
FX
3UC
Input
PLC
Output
Model
name
FX
3U
Input
PLC
Output
4.2.2

Functions and roles

Examples of terminal names and wiring (sink input) are for FX
0V
24V
S/S
Input
signal
X000
X000
Input
terminal
X000
The PLC receives signals from external switches
through input terminals.
An input relay (X) connected to an input terminal
inside the PLC is an electronic relay isolated
optically, and has many NO contacts and NC
contacts. These contacts can be arbitrarily used
inside the PLC.
These input relays cannot be driven by a program.
When
FX -32MT-LT
3UC
extended
X000 to X017 X000 to X357
16 points 240 points
Y000 to Y017 Y000 to Y357
16 points 240 points
FX -16M FX -32M
3U 3U
X000 to X007 X000 to X017
8 points 16 points
Y000 to Y007 Y000 to Y017
8 points 16 points
Program example
X000
X000
Y000
PLC
256
points
in total
FX -48M FX -64M
3U 3U
X000 to X027 X000 to X037
24 points 32 points
Y000 to Y027 Y000 to Y037
24 points 32 points
Series PLC.
3U
X001
Y000
Y000
NO contact
Y000
NC contact
The PLC outputs signals to external loads through
output terminals. Contacts for external output
(output devices such as relay contacts, TRIACs and
transistors) of output relays are connected to output
terminals inside the PLC. An output relay has many
electronic NO contacts and NC contacts. These
contacts can be arbitrarily used inside the PLC.
Differences in operations between external output
contacts (output devices) and internal contacts are
explained on the next page.
4 Devices in Detail
4.2 I/O Relays [X, Y]
When
FX -80M
3U
extended
X000 to X047 X000 to X367
40 points 248 points
Y000 to Y047 Y000 to Y367
40 points 248 points
External power
supply
COM1
Y000
Load
Output terminal
1
2
3
4
256
points
in total
5
6
7
8
9
10
73