Industrial Mini PC DCA-M400

Twelve Serial Ports, GPIO, and 9–36 V Input

Most mini PCs are specified on CPU and memory. An industrial PC is specified on what it can connect to, and by that measure the DCA-M400 is a different category of device: six DB9 COM ports on the rear panel, four of them configurable as RS422 or RS485, plus a Phoenix terminal that extends another six RS232 channels — twelve serial ports in total — alongside a 7-in / 7-out GPIO header.

That is the specification of a machine controller, not a desktop computer. It is what you need when the equipment in the building was built before Ethernet.

Why Serial Ports Still Decide Industrial Projects

Serial survives because it is simple, deterministic and optically isolated when it needs to be. The devices that use it are not going away:

• Weighing scales — retail, warehouse and laboratory, almost universally RS232.
• PLCs and machine controllers — RS485 for multi-drop networks of drives and sensors.
• Barcode and RFID readers — fixed-mount industrial readers on serial, not USB.
• Payment terminals and PIN pads — serial or USB-serial in integrated POS builds.
• Legacy POS peripherals — receipt printers, cash drawers via printer, customer displays on CD5220.

A USB-to-serial adapter works, until it does not: adapters drop under sustained load, change COM numbers after a reboot, and add a driver dependency to an appliance that should not have one. Twelve native ports remove that class of problem entirely, and RS485 on four of them lets a single port address a bus of devices rather than one.

RS422 and RS485 matter specifically because they are differential: they run hundreds of metres in an electrically noisy environment where RS232 manages fifteen. In a factory or a refrigerated warehouse, that difference is the reason a controller is installed in a cabinet rather than next to the machine.

GPIO: Reading Switches, Driving Relays

The GPIO header provides seven inputs and seven outputs. On an industrial PC this is how the computer stops being a computer and becomes part of the machine:

• Inputs read door switches, presence sensors, emergency-stop states, level floats, push buttons.
• Outputs drive relays, indicator lamps, buzzers, solenoid valves, conveyor start signals.

Without GPIO, that job goes to a separate PLC or a USB I/O module — another device, another power supply, another protocol. A 7/7 header covers a surprising amount of machine logic: start and stop, a safety interlock, a stack-light, and half a dozen sensors.

The CPU Matrix: 4th to 13th Generation

This is the unusual part of the specification: the platform is offered across ten generations of Intel Core processors, from a 4th-generation i5-4278U up to a 12-core i7-1260P.

Why that matters commercially rather than technically:

• Longevity of a deployed design. A machine builder that qualified a chassis and a back panel can keep shipping the same product for years, moving to a newer CPU as availability changes, without recertifying the mechanical design.
• Price points. An older-generation i5 is dramatically cheaper than a current i7 and often more than adequate for a controller that runs one application.
• Matching the workload. A kiosk controller runs fine on a 15 W dual-core; a video-wall player or an on-machine vision application needs the i7-1260P’s 12 cores and Iris Xe graphics.

The consequence for a buyer is that the CPU is a configuration choice rather than a fixed specification — which is why the memory type varies with it (DDR3L for 4th generation, DDR4 for 6th to 11th, DDR5 in the later generations) and the storage slot differs (mSATA on 4th generation, M.2 NVMe from 6th onward).

Networking: Up to Four 2.5 GbE

Networking is 2 × Intel i210/i219 plus 2 × Intel i226V 2.5 GbE, and on 11th to 13th generation CPUs it becomes 4 × Intel i226V. All Intel controllers, all with in-kernel driver support.

For a device that may sit between a machine network and an office network, four ports on independent controllers means physical segmentation without a managed switch — the same argument as on the smaller M200, at a higher performance tier.

Power: 9 to 36 Volts

The input is a 3-pin Phoenix terminal accepting 9–36 V DC, with a recommended 12 V / 5 A supply for 4th–8th generation builds and 19 V / 4.74 A for 10th–13th. The AC adapter is 100–240 V.

The wide DC range is the specification that makes vehicle and plant installation possible: a 12 V vehicle system actually swings between 11 and 14.5 V, a 24 V industrial system between 19 and 29 V, and both produce transients well outside that. A fixed 12 V input device fails on the first cold start or load dump; a 9–36 V input absorbs it.

Two further details belong to the same story. The ATX/AT quick switch selects between soft power-on and power-on-with-supply, which is what an unattended machine needs after a power cut. And the Phoenix terminal connector is a screw-down block rather than a barrel jack, because a barrel jack in a vibrating environment falls out.

Physical and Environment

248 × 150 × 83 mm in an aluminium alloy body, 2.2 kg net and 3.5 kg gross. Operating range −20 to 60 °C, storage −20 to 70 °C, 10–90% RH at 30 °C non-condensing.

−20 °C operation is the number that separates this from a commercial mini PC. It is what allows installation in a cold store, an unheated plant room or an outdoor cabinet — and it comes from the combination of an aluminium case as heatsink, industrial-grade components and no fan to seize.

Remaining I/O: 1 × VGA, 1 × HDMI, 4 × USB 3.0, 2 × USB 2.0, 1 × PS/2 combo, mic and speaker jacks, an embedded SIM slot for 3G/4G, a reset button and a CMOS clear button. The BIOS is American Megatrends.

Where the DCA-M400 Fits

• Machine and line control. Twelve COM ports, RS485 buses, GPIO for interlocks and stack lights.
• Kiosk and self-service controllers. Serial peripherals, GPIO for door and sensor, wide voltage.
• Vehicle and mobile installations. 9–36 V input, ATX/AT switch, screw terminals.
• Cold store and plant rooms. −20 to 60 °C operating range.
• Edge gateway with segmentation. Up to four Intel 2.5 GbE ports.
• Not for a plain office desktop. Over-specified, and the COM ports are wasted — a commercial mini PC is cheaper.
• Not where a discrete GPU is required. Integrated Iris Xe at most.

The Industrial Mini PC Range

• DCA-M100 — Intel N100, three display outputs, 2 × GbE, 2 × RS232, watchdog and PXE.
• DCA-M200 — J4125, 4 × 2.5 GbE, fanless, RS232, Mini-PCIe, 139 × 126 × 40 mm.
• DCA-M300 — the fanless J4125 platform in a vehicle and industrial-terminal configuration.
• DCA-M400 — this unit. 4th–13th gen Core, 12 COM ports, GPIO, 9–36 V, −20 to 60 °C.

Frequently Asked Questions

How many serial ports does it have?

Six DB9 ports on the rear panel, four of which support RS422/RS485, plus a Phoenix terminal that extends six more RS232 channels — twelve in total.

Can it run from a vehicle supply?

Yes. The input accepts 9–36 V DC on a screw terminal, which covers 12 V and 24 V systems including their transients.

What is the GPIO for?

Seven inputs and seven outputs for switches, sensors, relays, lamps and interlocks — machine control without a separate PLC or I/O module.

Which CPU should I choose?

A 15 W part for a controller running one application; a 28 W i7 or the 12-core i7-1260P for vision, video walls or multiple concurrent workloads. Older generations are significantly cheaper.

Does the memory type change with the CPU?

Yes — DDR3L on 4th generation, DDR4 on 6th to 11th, and DDR5 on the later generations. Storage is mSATA on 4th generation and M.2 NVMe from 6th onward.

What is the warranty?

One year. OEM/ODM configuration of CPU, port layout, logo and system image is available — ask at quotation stage.

Next step: send us the device list you need to connect (port types and count), the supply voltage and the operating environment — we will specify the CPU generation and confirm a factory-direct quote. Email sales@dcapos.com or contact us.

Related: DCA-M200 fanless mini PC · DCA-M100 mini PC · industrial mini PC range · POS systems