Embedded Modules
A complete 4G router on a 74 × 42 mm board. Two Ethernet ports, 802.11b/g/n Wi-Fi, a serial line and a SIM socket — with the routing, NAT, firewall and watchdog firmware already on the board. Design your own enclosure around it, put your brand on the outside, and skip the network development work.
Supply under your own brand, from 1 unit — including the module label and the firmware splash screen. See OEM & private label options →
Overview
If you are building a camera, a charging cabinet, a vending terminal or a piece of industrial equipment that needs a cellular uplink, you have two options: design the network section yourself, or buy a board that already has it. The M400-D is the second option — a four-layer router board with the 4G modem, the Wi-Fi radio, the two Ethernet PHYs and the firmware already integrated and tested.
Dial-up (DHCP / Static IP / PPPoE), NAT, DNAT, DMZ, port forwarding, virtual server, port triggering, firewall, MAC filtering, access control and a hardware and software watchdog. None of it has to be developed again.
LAN1 is WAN/LAN adaptive, so a single board covers both layouts: two LAN ports for a downstream switch, or one WAN plus one LAN when the module is the gateway. Nothing changes in the hardware — it is a configuration choice.
The orderable serial option (RS232 or RS485) turns the module into
a transparent DTU as well as a router, which means a controller with a serial port can be put
online without an extra gateway in the enclosure.
CN, EA, AU, NA, SA, JP and GL band versions share the same footprint, connector positions and firmware. You design one enclosure and one carrier board, then stock the region versions you actually sell.
Specifications
Three groups, same order on every module page: cellular and networking first, interfaces and power second, mechanical and environmental third.
W0 — no Wi-Fi versionS2) version on requestNeed a figure that is not listed here — throughput, radio sensitivity, mechanical drawing tolerances, connector part numbers? Email us for the datasheet, or ask us for the document set for this board.
Pin-out
This is the page most integrators open first. All six board connectors are documented below with pin numbers, signal names and functions, so you can lay out your carrier board before you order a first article. If you send us your schematic, we will check the pin mapping against our own fixture before you commit to tooling.
| Pin | Signal | Function |
|---|---|---|
| 1 | VCC | Power |
| 2 | RXD0 | Receive, TTL level |
| 3 | TXD0 | Transmit, TTL level |
| 4 | GND | Ground |
| Pin | Signal | Function |
|---|---|---|
| 1 | VIN | DC input, positive |
| 2 | GND | DC input, negative |
| Pin | Signal | Function |
|---|---|---|
| 1 | TXP | Ethernet differential pair, transmit |
| 2 | TXN | Ethernet differential pair, transmit |
| 3 | RXN | Ethernet differential pair, receive |
| 4 | RXP | Ethernet differential pair, receive |
| Pin | Signal | Function |
|---|---|---|
| 1 | TXN | Ethernet differential pair, transmit |
| 2 | TXP | Ethernet differential pair, transmit |
| 3 | RXN | Ethernet differential pair, receive |
| 4 | RXP | Ethernet differential pair, receive |
| Pin | Signal | Function |
|---|---|---|
| 1 | VCC | 3.3 V |
| 2 | RXD / B | Serial input (RS-485 B on the 485 version) |
| 3 | TXD / A | Serial output (RS-485 A on the 485 version) |
| 4 | GND | Ground |
| Pin | Signal | Function |
|---|---|---|
| 1 | GPIO0 | Digital I/O |
| 2 | GPIO37 | Digital I/O |
| 3 | GPIO3 | Digital I/O |
| 4 | GND | Ground |
Two notes before you design in. The J3 power connector is labelled DC 12V
on the datasheet drawing, while the board is rated 5–12 V — tell us your rail voltage and
we will confirm the input range for your version in writing. And J6 carries either RS-232
or RS-485 depending on the version ordered; the pin names stay the same, the electrical layer does
not. Ask us for the mechanical drawing with connector positions and mounting-hole dimensions.
Detailed specifications
The complete parameter set for this board. Data below is maintained by our engineering team — if a figure is critical to your design, ask us to confirm it in writing before you commit.
Certification note. The M400 series is covered by our RoHS test report C-DPHTL2505191005E. We hold no radio type approval for the module line: a module is integrated into your product, so type approval is the responsibility of the brand owner in each destination market. Ask us for the reports and the compliance file we can hand over before you plan a launch.
Build your part number
Module configurations are built to order, so the configuration is expressed in the part number. Read the table, assemble the code, and send it to us — we will confirm availability and lead time for that exact combination.
CN ChinaEA Europe, Asia, Africa & AustraliaAU AustraliaNA North AmericaSA South AmericaJP JapanGL Global4GA 4G LTE4GQ 4G LTE4GC1 4G Cat-1W0 No Wi-FiW4 Wi-Fi 4W6 Wi-Fi 6S1 Single SIMS2 Dual SIMRS232RS485TTLM400-D-CN-4GA-W4-S1-RS485
Send us the code you need — for example M400-D-EA-4GA-W4-S1-RS485 — and we
will come back with availability, lead time and pricing. If you are not sure which region
version fits your market, tell us the destination country and your operator and we will match
the band plan for you.
Regional versions
Choose the version that matches the band plan of the market you sell into. All versions share the same footprint, connector layout and firmware, so one enclosure design covers every region.
FDD-LTE B1 / B3 / B5 / B8TDD-LTE B38 / B39 / B40 / B41China Mobile, China Unicom and China Telecom 4G accessFDD-LTE B1 / B3 / B5 / B7 / B8 / B20TDD-LTE B38 / B39 / B40 / B41FDD-LTE B1 / B3 / B5 / B7 / B8 / B20 / B28TDD-LTE B38 / B40 / B41FDD-LTE B2 / B3 / B4 / B5 / B7 / B8 / B12 / B13 / B17 / B25 / B26 / B66TDD-LTE B41Approvals for the US market are confirmed per model — ask us before you plan a launchFDD-LTE B2 / B4 / B5 / B7 / B8 / B28TDD-LTE B40FDD-LTE B1 / B3 / B8 / B18 / B19 / B26TDD-LTE B41FDD-LTE B1 / B2 / B3 / B4 / B5 / B7 / B8 / B17 / B20 / B28TDD-LTE B38 / B39 / B40 / B41Products sold across several regions, or stock kept for mixed destinationsRegional versions other than those listed are produced on request. Tell us the destination country and your operator, and we will confirm the band set before you freeze the design.
Where it fits
This board is the network section of a product, not a product by itself. It is the right part when you already have an enclosure, a production line and a brand — and the wrong part when what you need is a box that goes on a wall.
Tell us what you are building — the enclosure size, the power rail, the connectors you already standardised on and the region you sell into. If the M400-D is the wrong shape, we will say so and point you at the board in the family that fits.
Applications
Typical products our module customers build around this board.
Image transmission over the 4G link, with the camera controller on the serial port or the LAN port.
Charging piles and meter cabinets that report over 4G and are polled over RS-485.
Payment terminals and vending controllers that need a private, always-on uplink.
A PLC or controller with a serial port put online without redesigning the panel.
Door and gate hardware where the network section sits on your own board, not in a separate box.
Standalone sensors and data loggers that push readings to a cloud platform over 4G.
Downloads
The datasheet is sent by email on request. Integration drawings come with your quotation, and the user manual and firmware are released after a short form so we can match them to the revision you are designing in.
Full parameter table, ordering code and regional band versions.
Mechanical drawing with board outline and mounting holes, plus the connector positions and the pin-out table in a printable form.
Manual and current firmware for the M400-D, released after a short form.
Looking for something else for this model? All documents for the M400-D →
Keep looking
4G and 5G board-to-board modules with one, two and three Ethernet ports, Wi-Fi, TTL and USB interfaces.
If you need a housed unit with a DIN-rail mount and a power adaptor, the T300 range is the same technology in a box.
Your brand on the module label and in the firmware, from one unit.
Get in touch
Tell us the part number you need, or describe the product you are building and the region you sell into, and we will come back with availability, lead time and pricing. Drawings and the pin-out sheet are included with every quote.