Mitsubishi FXo/FXon PLC Hardware Practice

Mitsubishi FXo/FXon PLC Hardware Practice

Key points for product positioning and selection

The FXo and FXon in Mitsubishi Electric's MELSEC-F series are compact PLCs designed for small automation equipment. The most significant difference between the two is that FXo does not have scalability, and all I/O points are fixed; FXon can be expanded, with a maximum system I/O of 128 points, and supports special functional modules such as analog and communication adapters. In applications that require flexible configuration and may increase I/O in the future, FXon is the only choice.

Basic Model Identification

Based on the model string on the product nameplate, the power type, output type, and certification specifications can be quickly determined. Standard formats such as FX0-14MR-ES/UL or FXON-40MT-DSS.

Power supply and voltage: AC (100-240V) or DC (24V). The AC version provides an internal 24V service power supply (which can be used for input circuits), while the DC version requires an external 24V power supply.

Output type: R=relay output; T=transistor output.

I/O points: For example, 14 represents 8 inputs and 6 outputs, 20 represents 12 inputs and 8 outputs, and 30 represents 16 inputs and 14 outputs. FXon-24Mx actually occupies 32 points of the system (16 in and 16 out), but there are only 24 physical ports.

Terminal arrangement: World Spec S/S terminals allow for the selection of Sink or Source input modes through wiring; The Japanese specification is fixed as Sink.

When selecting, it is necessary to confirm whether expansion is needed, whether high-speed counting or pulse output (supported by transistor type) is needed, and environmental certification requirements (UL, ABS, DNV, etc.).

Installation environment and mechanical dimensions

2.1 Environmental conditions

All FXo/FXon products must be installed in control cabinets that comply with IP20 protection level and meet the following environmental parameters:

Project specifications

Working temperature 0~55 ° C

Storage temperature -20~70 ° C

Humidity 35-85% RH, no condensation

Altitude ≤ 2000m

Pollution level 2 (non-conductive dust)

Installation Category II

Anti vibration (direct installation) 10~55Hz, 0.5mm amplitude, 2G, 2h for each of the three axes

Anti vibration (DIN rail installation) 10~55Hz, 0.5mm amplitude, 0.5G, 2h for each of the three axes

Resistance to impact 10G, 3 times in each direction

Special attention: Do not install in environments with corrosive gases, conductive dust, strong impact, or condensation. Prevent conductive foreign objects such as metal shavings from falling into the interior of the casing during installation.

2.2 Mechanical installation method

There are two installation methods to choose from:

DIN rail installation (recommended): Use a 35mm wide DIN rail (EN 60715). Insert the upper part of the device into the guide rail and push the lower part forward until the spring clamp is locked. When disassembling, use a screwdriver to pull down the spring clip and lift the device up at the same time. Not suitable for strong vibration environments.

Direct screw installation: Fix with M4 screws through the mounting holes (diameter 4.5 or 5) at the four corners of the housing. The external dimensions of FXo and FXon are different, and the opening size should refer to the drawings in the manual (width: FXo-14 is 100mm, FXon-60 is 185mm, etc.).

The installation direction must be horizontal, and vertical or inverted installation is prohibited. To ensure heat dissipation, a space of ≥ 50mm should be reserved above and below the device, and there is no need for additional gaps on both sides. If using a double-layer layout (FXon only), FXon-65EC 650mm extension cable can be selected to connect to the second layer, and it should be noted that a maximum of one cable can be used per system.

Power wiring and grounding specifications

3.1 AC power supply model (ES/UL suffix)

Power terminal: L (live wire), N (neutral wire), PE (protective grounding).

Rated voltage: 100-240V AC,+10%/-15%, 50/60Hz.

Surge current: FXon maximum 50A 5ms (at 200V AC), FXo maximum 25A 2ms.

Power consumption: FXo-14MR is about 20VA, FXon-60MR is about 60VA.

Important rules:

Easy to operate circuit breakers or isolation switches must be installed outside the PLC for emergency power outages and maintenance isolation.

It is recommended to install 5-10A fuses for every 4 output points to prevent short circuits in the output circuit from damaging the circuit board.

The AC power version provides a 24V DC service power supply (located at+24V and COM terminals) with a capacity of approximately 200-400mA depending on the model, which can be used to power input switches. Do not connect external 24V power to this service terminal to avoid damaging the internal circuit.

3.2 DC power supply model (DS/DSS suffix)

Terminal:+(24V+), - (0V).

Voltage range: 24V DC+10%/-15%.

Surge current: DC type is much larger than AC type - FXo has a maximum of 60A 1.5ms, FXon has a maximum of 60A 50 μ s. When designing the system, it is necessary to ensure that the upstream DC power supply can withstand this surge.

Power consumption: FXo-14MT is about 10W, FXon-60MT is about 24W.