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Serial port cards are essential for connecting legacy devices or specialized equipment to modern computers. Ensuring compatibility and reliable performance is key, especially in industrial, scientific, or networking environments where these connections are critical. Choosing the right card can prevent connectivity issues and ensure seamless operation of your peripherals.
1. PCIE-SE2 allow users add 2X RS232 BD9 serial Ports on desktop PCs or industrial devices by motherboard PCI Express slot.
2. Seamless connect to serial DB9 ports device such as POS system, industrial testing and control device, security system, logistic management equipment, scanners and printers.
3. Need to install driver on Windows XP, Vista, 7, 8.x, 10, 11 (32/64bit) systems. Linux kernel 2.6.x, 3.x, 4.x, 5.x need to refer compile source code from the driver CD.
4. Selected by ASIX AX99100 solution supports on chip 256-byte depth FIFO in transmit. Works on Intel, AMD, ARM hardware platform.
5. The full-size bracket on this expansion card will works on standard size PCs. The 2X low profile bracket for slim PCs. Based on PCIE X1 interface, will works on X1, X4, X8, X16 slot.
6. ATTENTION: 1. Must make sure users PCs have empty PCIE slot.2. Slim PC users need change to low profile bracket by hand. 3.Please install correct driver from Mini-CD for desktop PCs.
MEETS INDUSTRY STANDARDS: The 2-port PCI express serial card is compliant with PCI Express 1.0a specification, and it's compatible with 1x, 2x, 4x, 8x and 16x PCI Express slots.
MAXIMUM COMPATIBILITY: The dual port DB9 to PCIe adapter is ideal for system upgrades in a wide range of applications including manufacturing equipment, POS equipment, and security devices.
HIGH-PERFORMANCE COMMUNICATION: The low-profile serial card delivers high-performance serial communication, with support for data transfer rates of up to 460Kbps.
SIMPLE INSTALLATION: The PCI dual serial adapter features IRQ sharing and supports plug-and-play connection. It has a standard-profile bracket installed, and an optional low-profile bracket.
Compliant with ExpressCard/34mm Standard; Compatible to 1-Lane (x1) PCI-Express Throughput.
Operating System: Windows 32bit 2000/XP/2003 Server/Vista and 64bit XP/2003 Server/Vista/WIN7/WIN8/WIN10/WIN11/Linux. (If there was any problem with PCIE 2 port serial expansion card, pls feel free to contact us, we will provide a solution within 24hrs.)
1 PORT SERIAL CARD: Serial controller card w/ 16950 UART based on ASIX AX99100, allows 1x DB9 port w/bi-directional RS232 speeds up to 921.6Kbps per port, available 256 byte FIFO buffer & 9th data bit; Upgraded version of our popular card PEX1S952LP
OPTIONAL CONFIGURABLE POWER: PCI Express RS232 serial adapter card provides choice of 12v, 5v, or none through pin 9 w/up to 2A total
STANDARD PROFILE & LOW PROFILE BRACKET: PCIe serial card comes w/ a low profile bracket pre-installed & 1x full profile bracket is incl for versatile install; Supports Windows & Linux
VERSATILE APPLICATIONS: For low/standard profile desktop/servers w/ uses in point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, scanner, oscilloscope
PCI CARD WITH SERIAL & PARALLEL PORTS: Using one PCI bus, add a DB25 parallel & two DB9 RS232 ports to your computer; Serial Parallel PCI Card installs in 2x full profile or 3x low profile expansion slots; Auto IRQ & IO assignment; Supports IRQ Sharing
TECH SPECS: Parallel Speeds up to 1.5Mbps | Supports SPP/Byte/ECP/EPP modes | Compatible with IEEE 1284 | Asix MCS9865 chip | RS-232 speeds up to 115.2 Kbps | 16C550 UART | 256 byte FIFO buffer | 5-9 bit character | Even, Odd, No, Space or Mark Parity
VERSATILE APPLICATIONS: PCI expansion combo card adds LPT Printer & two COM serial ports working with printers, scanners, plotters, point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, oscilloscope
STANDARD PROFILE & LOW PROFILE BRACKETs: PCI multiport Parallel LPT & dual serial COM adapter card installs using 2x standard bracket (pre-installed) or 3x low profile brackets (incl); Supports Windows 7 and up, Linux 2.6.x to 5.x
Expansion Interface: Easily add 2 RS232 DB9 serial ports to desktop PCs or industrial devices via the motherboard's PCI Express slot, meeting a variety of device connection needs
Wide Compatibility: Seamlessly connect to DB9 serial devices such as POS systems, industrial testing and control equipment, security systems, logistics management devices, scanners, and printers, suitable for various application scenarios
Multi-Platform Support: Driver compatible with Windows XP, Vista, 7, 8.x, 10, 11 (32/64-bit) and Linux kernels 2.6.x, 3.x, 4.x, 5.x, ensuring smooth installation and use across different systems
Efficient Data Transmission: Utilizes the ASIX AX99100 solution, supporting 256-byte deep FIFO transmission, compatible with Intel, AMD, and ARM hardware platforms, providing stable serial data transmission performance
Flexible Installation: Comes with a standard full-size bracket for standard PCs, and includes 2 low-profile brackets for perfect compatibility with slim PCs. Based on the PCIe X1 interface, compatible with X1, X4, X8, and X16 slots
Important: Ensure your PC has an available PCIe slot, switch to the low-profile bracket for slim PCs, and install the correct driver from the Mini-CD for desktop use
2 PORT SERIAL CARD: Serial controller card w/16950 UART based on ASIX AX99100, allows 2x DB9 ports w/bi-directional RS232 speeds up to 921.6Kbps per port, available 256 byte FIFO buffer & 9th data bit; Upgraded version of our popular card PEX2S952LP
OPTIONAL CONFIGURABLE POWER: PCI Express RS232 serial adapter card provides choice of 12v, 5v, or none through pin 9 w/up to 2A total; Each of the 2 ports are individually configurable
STANDARD PROFILE & LOW PROFILE BRACKET: PCIe multiport serial card comes w/ low profile bracket preinstalled & a full profile bracket is incl for versatile install; supports Windows XP and up & Linux
VERSATILE APPLICATIONS: For standard/low profile desktop/servers w/ uses in point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, scanner, oscilloscope
2-PORT PCIE SERIAL CARD: On-board DIP switches allow each DB9 serial port to operate in its own independent mode, enabling the connection of RS-232, RS-422, and RS-485 devices; LED indicators to monitor data transmit/receive status
CONFIGURABLE POWER: Dual-Port PCI Express Serial Adapter Card features configurable power of 12V (1.5A per port), 5V (1.5A per port), or no power (RI) over pin 9 via auxiliary SATA power; Per-Port power modes are individually configurable via jumpers
APPLICATIONS: Ideal for desktops and servers, with a wide range of uses such as point-of-sale terminals, PLCs, factory control and automation, scientific sensors, medical equipment, scanners, and oscilloscopes; DB9 ports work with screw-locking cables
STANDARD & LOW PROFILE BRACKETS: TAA-Compliant Serial Card is equipped with a standard profile bracket (pre-installed), and includes two low-profile brackets for compatibility with small form factor desktops/servers
TECH SPECS: Asix AX99100 Chipset; 16C450 and 16C550 UART compatible; 2x 9-Pin D-Sub Ports; Max Baud 921.6Kbps per port; 256 Byte FIFO; COM Retention; Supports Windows and Linux; Odd/Even/Mark/Space/None Parity Modes; 5/6/7/8/9 Data Bits; PCIe 2.0 x1
Last update on 2026-07-18 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Serial Port Cards
Understanding Serial Port Types
Serial port cards primarily offer RS-232 interfaces, but variations exist. RS-422 and RS-485 offer longer distances and multi-drop capabilities, often used in industrial automation and networking. Consider the specific protocol your devices require. Most cards utilize PCI, PCIe, or USB interfaces to connect to your computer. PCIe is the modern standard for internal cards, offering higher bandwidth than older PCI slots.
Key Features to Consider
Number of Ports: Determine how many serial devices you need to connect simultaneously. Cards are available with one, two, four, or even more ports.
Connector Type: Most common is DB9 (9-pin male or female), but some devices may use DB25 or other connectors. Ensure the card's connector matches your devices.
Chipset: The chipset (e.g., FTDI, ASIX, CH340) influences driver support, stability, and performance. Look for well-regarded chipsets known for reliability.
Power Requirements: Some serial devices require power from the serial port itself (often referred to as "phantom power"). Check if the card offers selectable or adjustable power output if needed.
Operating System Compatibility: Ensure the card has drivers available for your specific operating system, whether it's Windows, macOS, or Linux.
Installation and Driver Considerations
Internal cards (PCIe) require opening your computer case. External USB-to-serial adapters are plug-and-play for most modern systems. Always download the latest drivers from the manufacturer's website to ensure optimal performance and compatibility. Check reviews for common driver issues or installation hurdles.
Use Case Scenarios
These cards are vital for connecting point-of-sale systems, industrial machinery, scientific instruments, GPS receivers, and older networking equipment. For robust, long-distance communication or connecting multiple devices on a single bus, consider RS-485 or RS-422 options. For general-purpose device connections, RS-232 is usually sufficient.
Frequently Asked Questions
What is the difference between RS-232, RS-422, and RS-485?
RS-232 is a single-ended standard for short-distance communication. RS-422 and RS-485 are differential signaling standards that offer better noise immunity, longer cable lengths, and the ability to connect multiple devices on a single bus.
Do I need a DB9 or DB25 connector?
This depends on the serial port connector on your device. DB9 is the most common for modern serial devices, while DB25 is found on older equipment or specific networking gear. Always check your device's specifications.
What is a serial port card chipset?
The chipset is the main integrated circuit on the card that controls its functionality. Popular chipsets like FTDI are known for their reliability and broad driver support across various operating systems.
Can I use a USB-to-serial adapter instead of an internal card?
Yes, USB-to-serial adapters are a convenient alternative, especially for laptops or systems without available internal slots. They are generally easy to install and compatible with most modern operating systems.
What is phantom power on a serial port?
Phantom power is a small amount of voltage supplied through the serial port's pins to power certain devices. Some serial port cards offer selectable power output options to accommodate devices that require it.
How do I know if a card is compatible with my OS?
Check the product specifications or manufacturer's website for a list of supported operating systems. Look for cards that explicitly mention support for your version of Windows, macOS, or Linux.
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