How to Add 4 RS422/RS485 Serial Ports to Your Mini PC with an M.2 Adapter Card
If you're working with industrial automation, SCADA systems, or embedded computing, you've likely run into a common challenge: modern mini PCs and NUCs simply don't come with RS422 or RS485 serial ports. Yet many industrial devices — PLCs, sensors, meters, and CNC machines — still rely on these protocols for reliable, long-distance communication.
The good news? You can add 4 independent RS422/RS485 serial ports to your mini PC without any external adapters or USB dongles — just by using an M.2 expansion card.
What Is an M.2 RS422/RS485 Serial Adapter Card?
An M.2 serial adapter card plugs directly into the M.2 B+M Key slot found on most modern mini PCs, NUCs, and embedded boards. Unlike USB-to-serial adapters, an M.2 card provides a stable, low-latency connection that is far more suitable for industrial environments.
The Lekuo M.2 B+M Key 4-Port RS422/RS485 Serial Adapter Card (SKU: MW84Z41) gives you 4 fully independent serial ports in a compact form factor — all from a single M.2 slot.
Key Features
- 4 Independent Ports: All 4 RS422/RS485 ports operate simultaneously without signal interference, enabling multi-device communication in parallel.
- Dual-Mode Support: Each port supports both RS422 (full-duplex) and RS485 (half-duplex), giving you flexibility to connect a wide range of industrial devices.
- Long-Distance Communication: Supports up to 1200 meters in RS485 mode — ideal for factory floors, outdoor deployments, and large facilities.
- Compact M.2 Form Factor: Fits standard M.2 B+M Key slots, making it perfect for space-constrained mini PCs and embedded systems.
- Wide OS Support: Compatible with Windows and Linux. Install the WCH CH382/CH384 chip driver and you're ready to go.
Who Is This For?
This card is designed for engineers and system integrators who need to:
- Connect PLCs, sensors, or meters to a mini PC in an industrial control cabinet
- Build SCADA or data acquisition systems with multiple serial devices
- Replace aging desktop PCs with compact mini PCs without losing serial port functionality
- Deploy embedded systems in space-constrained environments
Installation Overview
- Power off your mini PC and locate the M.2 B+M Key slot.
- Insert the adapter card into the slot and secure it with the mounting screw.
- Power on your system and install the WCH CH382/CH384 chip driver.
- The 4 serial ports will appear in your device manager, ready to use.
Typical Applications
- Industrial automation and PLC communication
- SCADA and HMI systems
- CNC machine control
- Environmental monitoring with RS485 sensors
- Smart metering and energy management
- GPS and positioning systems
Specifications at a Glance
- Interface: M.2 B+M Key
- Serial Ports: 4 x RS422 / RS485
- Communication Mode: Full-duplex (RS422) / Half-duplex (RS485)
- Max Distance: 1200m (RS485)
- OS Support: Windows, Linux
- SKU: MW84Z41
If you're looking to bring reliable industrial serial communication to your mini PC or embedded system, the Lekuo M.2 RS422/RS485 adapter card is a clean, professional solution that fits right into your existing hardware.