Справочник Пользователя для Mitsubishi Electronics FX3S-30MT/ESS-2AD

9 Input Wiring Procedures

9.1 Before Starting Input Wiring

Series Programmable Controllers

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.

For wiring examples, refer to Subsection 9.2.3.

• 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.

For wiring examples, refer to Subsection 9.2.4.

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

PLCs in input specifications (reference)

Sink input type only FX

PLCs (manuals in Japanese are supplied) and sink/source input type FX

PLCs

(manuals in English are supplied) have different model names.
• For sink input type only FX

PLCs, the [S/S] terminal and the [24V] terminal are connected internally,

unlike in FX

PLCs.

When replacing a sink input type only FX

PLC with a FX

PLC, short-circuit the [S/S] and [24V]

terminals, and use the [0V] terminal of the FX

as the [COM] terminal of the FX

for wiring.

• Sink/source input type FX

PLCs are configured in sink or source input mode using external wiring in the

same way as FX

PLCs.

24V

S/S

24V

S/S