Coolmay MX3G HMI PLC All in One 4.3 7 inch Mini Controller

Coolmay MX3G HMI PLC All in One 4.3 7 inch Mini Controller

The Coolmay MX3G Series is Coolmay's compact HMI + PLC all-in-one — a touch panel, PLC controller and Ethernet port integrated into a single panel-mounted unit. It forms a tier with the EX3S standard series: the MX3G focuses on compact size, a built-in network port and cost optimisation, while the EX3S focuses on higher I/O ceilings plus motion and process control functions. For standalone machines that need a moderate I/O count but must report data over a network, the MX3G is the better fit.

Built-in Ethernet is the most practical point. On many all-in-ones at this price level networking must be added as an option, whereas the MX3G series is officially specified with an integrated Ethernet port — the machine can join the plant network directly for remote program download, status reporting or connection to a supervisory system, with no additional gateway. This matters especially for export machinery: overseas customers want to see machine status on their own network, and a built-in port removes both the conversation and the retrofit cost.

Consistent with Coolmay's other series, the MX3G's PLC section is compatible with Mitsubishi FX3G, FX3U and FX3S and supports GX Works2 programming; the HMI uses Coolmay's mView software. Communication supports Modbus RS485. Engineers therefore need not learn a new environment — existing FX ladder programs and development habits carry over.

I/O configuration varies by model: the MX3G-43C-22MT (4.3") provides 12DI / 10DO (relay type up to 8 points); the MX3G-70C-48MT (7") provides 24DI / 24DO (relay type up to 12 points), with digital outputs selectable as transistor (MT, maximum load 500 mA) or mixed relay and transistor (MRT). The MX3G also offers customisation: the HMI can be fitted with ferroelectric memory to store historical data; the PLC can be fitted with four EKSTJ thermocouple inputs (supporting negative temperatures — note that thermocouples cannot be used at the same time as the built-in current/voltage inputs); and the HMI can be fitted with an extra RS485 port (which cannot coexist with the built-in RS232). Customisation has a minimum order quantity of 200 units.

Product Highlights

1. HMI, PLC and Ethernet in one unit — no separate PLC, no communication wiring and no extra gateway
2. Integrated Ethernet port — networking that is rarely standard at this price level; joins the plant network directly
3. PLC compatible with Mitsubishi FX3G / FX3U / FX3S — supports GX Works2, reusing existing projects and ladder programs
4. Compact housing — 4.3" and 7" panel mount, suited to small machines with limited cabinet space
5. Three digital output choices — transistor MT (max. load 500 mA) / relay MR / hybrid MRT
6. MX3G-70C supports 24DI / 24DO — a moderate point count covering most standalone machine needs
7. Modbus RS485 communication for connection to supervisory systems and third-party devices
8. Optional thermocouple inputs — four EKSTJ inputs (supporting negative temperatures) for temperature-controlled equipment
9. Optional ferroelectric memory — store historical data on the HMI with no external storage
10. HMI programmed with mView, consistent with Coolmay's entire HMI range, so the learning curve is short

Technical Specifications

4.1 Model matrix

4.2 Core technical data

Applications

FAQ

Q1. What is the difference between the MX3G and the EX3S, and how do I choose? Both are Coolmay HMI + PLC all-in-ones; both have PLC sections compatible with Mitsubishi FX3G/FX3U/FX3S and both are programmed with GX Works2 and mView. The difference is positioning: the MX3G is the compact model with an integrated Ethernet port and I/O from 12DI/10DO (4.3") to 24DI/24DO (7"), focused on cost optimisation and networking. The EX3S is the standard series with a higher I/O ceiling (series maximum 30DI/30DO and 16AD/8DA) and support for linear/circular interpolation and PID auto-tuning. Selection logic: moderate I/O plus networking → MX3G; higher point counts, analogue expansion or multi-axis interpolation → EX3S.

Q2. Is the Ethernet port standard, and what can it do? The MX3G series is officially specified with an integrated Ethernet port (a series characteristic rather than an extra option on each unit). It serves three main purposes: (1) remote program upload/download — no need to send anyone to site once a machine is exported; (2) status reporting — send running status, output counts and alarms to a supervisory system or the cloud; (3) plant network access — customers can see the machine in their own MES/SCADA. For export machinery, a built-in port removes the cost and commissioning effort of an additional gateway.

Q3. How do I choose between transistor MT, relay MR and hybrid MRT? Choose by load and switching frequency. Transistor MT: no contacts, long life and fast response, suited to high-frequency switching (high-speed pulse output, driving servos or steppers), but maximum load around 500 mA and DC loads only. Relay MR: high contact rating, usable for AC and DC, strong surge withstand, suited to contactor coils and solenoid valves, but with a finite mechanical life and unsuitable for high frequency. Hybrid MRT: some points use relays for heavy current loads and others use transistors for high-speed switching. Note each model's relay point limit — MX3G-43C relay type up to 8 points, MX3G-70C up to 12 points.

Q4. What are the constraints on the thermocouple customisation? Four EKSTJ thermocouple inputs can be added (supporting negative temperatures), but two hard constraints must be confirmed in advance: (1) the thermocouple inputs cannot be used at the same time as the device's built-in current/voltage analogue inputs — they share channels, so you must choose one or the other; (2) customisation has a minimum order quantity of 200 units, so small batches cannot be customised. If your machine needs thermocouples and 4–20 mA transmitter inputs simultaneously, consider the EX3S series instead or split the inputs across two modules.

Q5. Can the network port and the built-in RS232 be used at the same time? Note the version differences. On the MX3G-70C the built-in RS232 and the optional RS485 cannot be used at the same time — Coolmay states explicitly that it "cannot coexist with the built-in RS232". If you need RS485, confirm the serial configuration of the model or customised version you order. Settle this at selection stage, not after placing the order. The integrated Ethernet port and the serial ports are independent, so the network port is not subject to this restriction.

Q6. Can it reuse an existing Mitsubishi FX program? The PLC section is compatible with FX3G, FX3U and FX3S and is programmed with Mitsubishi's official GX Works2, so existing FX ladder programs and programming habits largely carry over, noticeably shortening the development cycle on retrofit projects. Two cautions: (1) check some FX-specific features (special registers, special module instructions) against Coolmay's official manual for support; (2) we strongly recommend running your main program on one sample unit before adopting in volume — the most effective way to control risk.