StarTech.com 4-Port PCI Express RS232 Serial Adapter Card - PCIe to Serial DB9 RS-232 Controller Card - 16950 UART - Windows/Linux

Enhance your system’s serial connectivity with a robust, high-performance four-port PCIe RS-232 expansion card. The StarTech.com 4-Port PCI Express RS232 Serial Adapter Card delivers four reliable DB9 RS-232 ports through a compact PCIe interface, making it an ideal solution for IT professionals, developers, and industrial environments that rely on legacy serial devices. Built around the proven 16950 UART technology, this controller card balances strong signal integrity with efficient CPU usage, helping you maintain stable communications with instruments, POS terminals, industrial equipment, and customized hardware stacks without bogging down your system.

• Four RS-232 DB9 serial ports controlled by a single PCI Express (PCIe) interface, enabling simultaneous, independent connections to multiple serial devices from a single computer.
• 16950 UART-based performance for high-speed, reliable serial communications up to 1 Mbps per port, supporting a wide range of baud rates and data formats.
• Broad OS compatibility with Windows and Linux support, designed to work with desktop workstations, servers, and embedded development setups.
• Flexible per-port configuration, allowing independent settings for baud rate, parity, data bits, stop bits, and flow control to match the exact requirements of each connected device.
• Durable, compact PCIe form factor with standard external DB9 connectors on the bracket, providing straightforward cabling and deployment in PCIe-equipped systems.

Technical Details of StarTech.com 4-Port PCI Express RS232 Serial Adapter Card

• Model: 4-Port PCI Express RS232 Serial Adapter Card (PCIe to Serial DB9 RS-232 Controller Card)
• Ports: 4 x RS-232 DB9 serial ports
• UART: 16950
• Bus Interface: PCI Express (PCIe) – typically PCIe x1 slot compatibility
• Operating System Support: Windows and Linux drivers available for broad compatibility
• Data Rate: Supports high-speed RS-232 communications, up to approximately 1 Mbps per port
• Connector Type: External DB9 connectors on the bracket for easy cabling
• Form Factor: PCIe add-in card suitable for a wide range of desktop and workstation configurations
• Mounting: Standard single-slot PCIe appearance with bracket-ready profile
• Applications: Ideal for serial device control, data collection, industrial equipment interfaces, and legacy instrumentation integration

how to install StarTech.com 4-Port PCI Express RS232 Serial Adapter Card

• Power off your computer and unplug the power cord. Ground yourself to avoid static discharge during installation.
• Open the computer case and identify a free PCIe slot (preferably PCIe x1 for this card). Remove the slot cover on the rear panel if needed.
• Insert the StarTech PCIe card firmly into the PCIe slot until it seats securely. Fasten the card’s bracket with a screw to the case for stability.
• Attach serial cables (DB9) to the four ports on the card’s bracket. Route cables neatly to your external devices, ensuring they are not strained or kinked.
• Power the system back on. The operating system should recognize the new serial ports automatically, or you may install drivers from StarTech’s website if prompted.
• In Windows, configure the four COM ports in Device Manager (e.g., COM1–COM4) to match your device settings. In Linux, the ports will typically appear as /dev/ttyS0–/dev/ttyS3; you can adjust baud rate, parity, and other settings via your preferred serial terminal or software.
• Test each port with a serial device or loopback test to verify data integrity and signal quality. If needed, adjust per-port parameters to ensure reliable communication.
• Document your port assignments to maintain consistent configurations across reboots. If any device requires a specific driver or software, install it per the device manufacturer’s instructions.

Frequently asked questions

• Q: What operating systems are supported by this StarTech PCIe RS-232 card?
  A: The card is designed for both Windows and Linux environments, with drivers provided by StarTech to ensure compatibility across current Windows versions and major Linux distributions.
• Q: How many serial devices can I connect at once?
  A: You can connect up to four RS-232 serial devices simultaneously using the four DB9 ports on the card’s bracket, enabling parallel communications with multiple peripherals or instruments.
• Q: What speeds can the ports handle?
  A: Each port supports high-speed RS-232 operation, with data rates up to about 1 Mbps, suitable for many industrial, lab, and data-collection applications requiring fast serial transfers.
• Q: Do I need special cables or adapters?
  A: The card provides four standard DB9 RS-232 connectors on the bracket, so you’ll typically use standard DB9 serial cables. Depending on your device, you may also need DCE/DTE adapters or null-modem cables for specific setups.
• Q: Is driver installation required?
  A: Yes. After installing the card, install the official StarTech drivers for Windows or Linux to ensure optimal performance and per-port configurability. In many cases, operating systems will detect the hardware automatically and apply basic drivers, but vendor drivers provide full feature support.
• Q: Can I configure each port independently?
  A: Absolutely. Each of the four ports can be configured with its own baud rate, data bits, parity, stop bits, and flow control settings, enabling precise matching to the requirements of each connected device.
• Q: What is the warranty on this card?
  A: StarTech typically offers a multi-year warranty on its PCIe expansion cards (commonly 2 years), reflecting confidence in reliability and long-term support. Check the exact warranty terms at the time of purchase for your region.
• Q: Can the ports be hot-swapped or used in a server environment?
  A: The card is designed for traditional, non-plug-and-play server operation. It should be installed in a powered-down system, and once installed and drivers loaded, the ports behave as standard serial interfaces. Always follow the server and OS guidelines when adding expansion hardware.