Functions And Roles - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]
2.2.2

Functions and roles

Examples of terminal names and wiring (sink input) are for the FX
0V
24V
S/S
X000
X000
Input
signal
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 normally-open (NO)
contacts and normally-closed (NC) contacts.
These contacts can be arbitrarily used inside the PLC.
These input relays cannot be driven by programs.
Program example
X000 X001
Y000
Y000
Y000
Y000
PLC
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 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.
2.2 Input/Output Relays [X and Y]
Series PLC.
3U
External power supply
COM1
Y000
NO contact
Output terminal
NC contact
2 Devices in Detail
Load
39
1
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