SystemBase Multi-8U Combo — USB to 8-Port RS422/RS485 Serial Converter Adapter

📋 Overview The SystemBase Multi-8U Combo is a professional-grade USB to 8-port serial converter that instantly adds eight RS422/RS485 (Combo) serial ports to any Windows or Linux computer through a single USB 2.0 connection. With communication speeds up to 921.6Kbps, ±15kV surge protection on every port, and per-port TX/RX LEDs for real-time status monitoring, the Multi-8U Combo is built for demanding industrial and commercial serial communication environments. Each port features a standard DB9 connector and can be independently configured for RS422 (Point-to-Point or Multi-Drop) or RS485 (Echo or Non-Echo) mode using convenient DIP switches — no software configuration required. The unit is USB bus-powered and includes a latching USB connector for secure, vibration-resistant connections. ⭐ Key Features 8 Serial Ports from One USB Connection — Adds eight RS422/RS485 Combo serial ports through a single USB 2.0 port High-Speed Communication — Supports data rates up to 921.6Kbps for fast, reliable serial data transfer Flexible RS422/RS485 Modes — Each port is independently configurable via DIP switches: RS422 Point-to-Point, RS422 Multi-Drop, RS485 Non-Echo, or RS485 Echo ±15kV Surge Protection — Built-in ESD protection on every port safeguards connected equipment from electrical surges TX/RX LEDs Per Port — Real-time transmit and receive activity indicators on each of the 8 ports for easy diagnostics Auto Toggling — Automatic control of bus I/O direction for RS422/RS485 communication, simplifying half-duplex setups Slew-Rate Limit Control — Configurable slew-rate limiting reduces EMI and signal reflections for long cable runs (limits speed to 250Kbps when enabled) Termination Resistor Support — Built-in 120Ω termination resistors for RS422 and RS485 can be enabled via jumper settings +5V Power on Pin 9 — Optional external DC adapter allows +5V power delivery through pin 9 of each DB9 connector to power connected devices DB9 Male or Female Serial Connectors — Available with either DB9 Male or DB9 Female serial connectors Latching USB Connector — Secure locking USB connection prevents accidental disconnection in industrial environments Plug and Play — Automatically detected by Windows and Linux — no reboot required USB Bus-Powered — No external power supply required for standard operation 📊 Specifications Parameter Detail Number of Ports 8 Bus Interface USB 2.0 Serial Interface Combo — RS422 / RS485 (switchable per port) Controller FT4232H Serial Connector DB9 Male or DB9 Female - Type selected above Max Communication Speed 921.6Kbps RS422 Signals TXD+, TXD−, RXD+, RXD− RS485 Signals TRXD+, TRXD− Surge Protection ±15kV ESD Termination Resistor 120Ω (RS422 and RS485, jumper-selectable) LED Indicators TX and RX per port (16 LEDs total) Power Supply USB VBUS (5V / 500mA) — external DC adapter optional Pin 9 Power Output +5V DC (requires external adapter, max 1A total) Supported OS Windows 7 / 8 / 10 / 11, Windows Server 2008+, Linux Kernel 2.6+ Architecture Support 32-bit and 64-bit Dimensions Approx. 210 × 84 × 26 mm (8.27 x 3.3 x 1 inches) L × W × H Weight Approx. 320g (11.3 oz) Manufacturer SystemBase Co., Ltd. 🔧 Setup & Configuration Connect the USB cable — Plug the latching USB cable into the Multi-8U Combo and connect the other end to an available USB port on your computer. You should hear a click when the latch engages. Install the driver — Windows will attempt automatic driver installation. If needed, download the latest driver from the SystemBase website and install manually. Linux users should contact SystemBase technical support at tech@sysbas.com. Configure each port — Use the 2-position DIP switch on each port to select your desired mode: RS422 Point-to-Point (OFF/OFF), RS422 Multi-Drop (OFF/ON), RS485 Non-Echo (ON/OFF, default), or RS485 Echo (ON/ON). Set termination resistors (if needed) — Use the internal jumpers to enable the 120Ω termination resistor for RS422 or RS485 as required by your network topology. Connect your serial devices — Attach your RS422 or RS485 devices to the DB9 connectors and verify communication using the TX/RX LEDs. 💡 Tip: The slew-rate limit jumper defaults to disabled (10M mode, max 921.6Kbps). For long cable runs where signal integrity is a concern, enable the 250K slew-rate limit mode to reduce EMI and reflection waves. 📌 DIP Switch Settings SW1 SW2 Interface Mode OFF OFF RS422 Point-to-Point OFF ON RS422 Multi-Drop ON (Default) OFF (Default) RS485 Non-Echo ON ON RS485 Echo 📦 What's in the Box 1x SystemBase Multi-8U Combo (RS422/RS485) Converter - Serial connector type selected above 1x Latching USB Cable 1x Quick Start Guide External DC power adapter is not included. Required only if supplying +5V power through DB9 pin 9. 🔌 Compatible With Windows 7, 8, 8.1, 10, and 11 (32-bit and 64-bit) Windows Server 2008, 2012, 2016, 2019, 2022 Linux (Kernel 2.6 and above — contact SystemBase for driver support) Any RS422 or RS485 serial device with DB9 connectivity 🎯 Applications Industrial automation and SCADA systems POS (Point of Sale) terminal networks Building management and access control systems Data acquisition and laboratory instrumentation Multi-device RS485 sensor networks Surveillance and security system integration CNC machine and PLC communication Telecommunications equipment management ⚠️ Important Notes The Multi-8U Combo model supports RS422 and RS485 only. If you need RS232 ports, look for the Multi-8U RS232 model. An external 5V DC adapter is required to supply power through pin 9 of the DB9 connectors. Without the adapter, pin 9 does not carry power. When using the slew-rate limit feature (250K mode), maximum communication speed is reduced to 250Kbps. For Linux driver support, contact SystemBase technical support at tech@sysbas.com. The latching USB connector provides a secure connection — press the spring button lightly and sweep to disconnect. 📄 Documentation & Resources Multi-8U COMBO User Manual, Utilities and Specifications Downloads (SystemBase Website)