Before Starting Input Wiring; Sink And Source Input - Mitsubishi Electric MELSEQ FX3S Series User Manual

FX Series Programmable Controllers
3S
User's Manual - Hardware Edition
9.1

Before Starting Input Wiring

9.1.1

Sink and source input

The input terminals (X) of the main unit are common to sink/source input of 24 V DC internal power.
1. Differences between the sink input circuit and the source input circuit
• Sink input [-common]
Sink input means a DC input signal with current-flow from the input
(X) terminal. When a sensor with a transistor output is connected,
NPN open collector transistor output can be used.
• Source input [+common]
Source input means a DC input signal with current-flow into the input
(X) terminal. When a sensor with a transistor output is connected,
PNP open collector transistor output can be used.
2. Method of switching between sink/source input
To switch the input type to sink or source input, wire the [S/S] terminal to the [0V] or [24V] ([-] or [+]) terminal.
• In the case of AC power type
- Sink input: [24V] terminal and [S/S] terminal are connected.
- Source input: [0V] terminal and [S/S] terminal are connected.
• In the case of DC power type
- Sink input: [+] terminal and [S/S] terminal are connected.
- Source input: [-] terminal and [S/S] terminal are connected.
3. Cautions for using
Mixed use of sink/source inputs.
It is possible to set all input terminals (X) of the main unit to either sink input or source input mode.
However, a mixture of sink and source input terminals cannot be set within a single unit.
Differences from FX
Sink input type only FX
(manuals in English are supplied) have different model names.
• For sink input type only FX
unlike in FX
When replacing a sink input type only FX
terminals, and use the [0V] terminal of the FX
• Sink/source input type FX
same way as FX
76
PLCs in input specifications (reference)
1S
PLCs (manuals in Japanese are supplied) and sink/source input type FX
1S
PLCs, the [S/S] terminal and the [24V] terminal are connected internally,
1S
PLCs.
3S
PLCs are configured in sink or source input mode using external wiring in the
1S
PLCs.
3S
→ For wiring examples, refer to Subsection 9.2.3.
→ For wiring examples, refer to Subsection 9.2.4.
PLC with a FX PLC, short-circuit the [S/S] and [24V]
1S 3S
as the [COM] terminal of the FX
3S
9 Input Wiring Procedures
9.1 Before Starting Input Wiring
L
N
24V
0V
S/S
X
L
N
24V
0V
S/S
X
PLCs
1S
for wiring.
1S