# PCIe RS232 1-port Serial Adapter Card StarTech PEX1S553LP — 16550 UART, DB9, Low Profile, PCIe

**URL:** https://aio.lv/en/product--startech-pex1s553lp--298299
**Data updated:** 2026-03-26 06:15 (EET)
**Category:** I/O Adapters & Controllers
**Manufacturer:** StarTech
**Manufacturer code:** PEX1S553LP
**EAN:** 0065030841733
**Warranty:** 2 Years
**Availability:** Out of stock

## Summary description

StarTech PEX1S553LP is a 1-port PCI Express RS232 serial adapter card with a DB9 output and 16550 UART. Designed for PCIe host systems, it features ASIX MCS9922CV-AA chipset, up to 460.8 Kbit/s baud rate, 128-byte FIFO and low-profile form factor. Suitable for adding legacy serial connectivity to Windows, Linux and macOS systems in industrial, POS and embedded applications.

## Long description

The StarTech PEX1S553LP PCIe RS232 1-port Serial Adapter Card provides a single DB9 serial port for systems with an available PCI Express slot. Built with an ASIX MCS9922CV-AA chipset and a 16550 UART, the card supports baud rates up to 460.8 Kbit/s and includes a 128-byte FIFO buffer. Its low-profile form factor and included full-height bracket make it suitable for both standard and small form factor computers. The adapter is designed to add legacy RS-232 connectivity for industrial devices, point-of-sale systems, embedded hardware and other equipment that require a single serial interface.
Advantages
The adapter uses a native single-chip PCIe design to maximize throughput while reducing CPU load compared with conventional bridge-chip serial cards. Compatibility across multiple operating systems, including Windows and a wide range of Linux kernels, ensures easy integration into existing environments. The card ships with a low-profile bracket and an optional full-height bracket, allowing installation in different case types without additional parts. A compact, low-weight printed circuit board and a DB9 output deliver a reliable, space-efficient serial solution.
Suitable for
Adding an RS-232 DB9 serial port to desktop and small form factor PCs
Connecting industrial controllers, sensors and legacy automation equipment
Point-of-sale (POS) systems and receipt printers that require serial communication
Embedded systems and development platforms needing a standard serial interface
Key specifications
Host interface: PCIe (PCI Express)
Output interface: RS-232 serial (DB9)
UART type: 16550 compatible
Chipset: ASIX MCS9922CV-AA
Maximum baud rate: up to 460.8 Kbit/s
FIFO buffer: 128-byte
Form factor: low profile / half-height with optional full-height bracket
Product colour: green (PCB)
Weight: 0.044 kg
How to use
Power down the computer and unplug it from the mains. Remove the case cover and locate an available PCI Express slot. If required, replace the installed low-profile bracket with the included full-height bracket to match your computer case. Insert the card into the PCIe slot and secure the bracket to the chassis. Reassemble the computer, reconnect power and boot the operating system. Install drivers if the OS does not automatically recognise the device; drivers are available for supported Windows versions and for Linux kernels in the stated range. Once installed, connect RS-232 devices to the DB9 port using a standard serial cable and configure serial port parameters (baud rate, parity, data bits, stop bits) as required by the attached equipment.
Usage recommendations
For stable communication, match the adapter baud rate and serial parameters exactly with the connected device and use shielded serial cables where possible. When installing in compact systems, ensure adequate airflow around the PCIe slot to maintain reliable operation. Reference the operating system compatibility list before deployment and keep drivers up to date for best performance.

## Specifications

### Weight & dimensions

| Feature | Value |
|---|---|
| Package weight | 130 g |
| Weight | 0.044 kg |
| Height | 20 mm |
| Depth | 105 mm |
| Width | 80 mm |

### Operational conditions

| Feature | Value |
|---|---|
| Operating relative humidity (H-H) | 5 - 85 |
| Storage temperature (T-T) | -20 - 100 |
| Operating temperature (T-T) | -10 - 80 |

### System requirements

| Feature | Value |
|---|---|
| Compatible operating systems | Linux, 
Mac OS 10.4.x |
| Server operating systems supported | Windows Server 2019, Windows Server 2016, Windows Server 2012 R2, Windows Server 2012, Windows Server 2008 R2, Windows Server 2003 |
| Linux operating systems supported | Yes |
| Mac operating systems supported | Mac OS X 10.8 Mountain Lion, Mac OS X 10.10 Yosemite, Mac OS X 10.4 Tiger, Mac OS X 10.5 Leopard, Mac OS X 10.6 Snow Leopard, Mac OS X 10.7 Lion, Mac OS X 10.9 Mavericks |
| Windows operating systems supported | Windows 8 Pro, Windows 8 Pro x64, Windows 8 x64, Windows 8.1, Windows 8.1 Enterprise, Windows 8.1 Enterprise x64, Windows 8.1 Pro, Windows 8.1 Pro x64, Windows 8.1 x64, Windows 95, Windows 98SE, Windows ME, Windows Vista Business, Windows Vista Business x64, Windows Vista Enterprise, Windows Vista Enterprise x64, Windows Vista Home Basic, Windows Vista Home Basic x64, Windows Vista Home Premium, Windows Vista Home Premium x64, Windows Vista Ultimate, Windows Vista Ultimate x64, Windows XP Home, Windows XP Home x64, Windows XP Professional, Windows XP Professional x64, Windows 8 Enterprise x64, Windows 10 Education, Windows 10 Education x64, Windows 10 Enterprise, Windows 10 Enterprise x64, Windows 10 Home, Windows 10 Home x64, Windows 10 Pro, Windows 10 Pro x64, Windows 11, Windows 11 x64, Windows 2000, Windows 2000 Professional, Windows 7 Enterprise, Windows 7 Home Basic, Windows 7 Enterprise x64, Windows 8 Enterprise, Windows 8, Windows 7 Ultimate x64, Windows 7 Ultimate, Windows 7 Starter x64, Windows 7 Starter, Windows 7 Professional x64, Windows 7 Professional, Windows 7 Home Premium x64, Windows 7 Home Premium, Windows 7 Home Basic x64 |

### Other features

| Feature | Value |
|---|---|
| Other operating systems supported | Windows XP Embedded, DOS |
| Drivers included | Yes |
| Manual | Yes |

### Logistics data

| Feature | Value |
|---|---|
| Harmonized System (HS) code | 84733020 |
| Products per master (outer) case | 75 pc(s) |
| Master (outer) case height | 315 mm |
| Master (outer) case length | 692 mm |
| Master (outer) case width | 365 mm |

### Packaging data

| Feature | Value |
|---|---|
| Package height | 32 mm |
| Package depth | 174 mm |
| Package width | 143 mm |

### Technical details

| Feature | Value |
|---|---|
| Compliance certificates | CE, RoHS |

### Features

| Feature | Value |
|---|---|
| FIFO (First In, First Out) | 128 |
| Baud rate | 460.8 Kbit/s |

### Design

| Feature | Value |
|---|---|
| Product colour | Green |
| Internal | Yes |

### Ports & interfaces

| Feature | Value |
|---|---|
| Peripheral (Molex) power connectors (4-pin) | 1 |
| Serial interface type | RS-232 |
| Serial ports quantity | 1 |
| Host interface | PCIe |
| Output interface | Serial |

### Performance

| Feature | Value |
|---|---|
| Chipset | ASIX - MCS9922CV-AA |

## FAQ

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All StarTech products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized StarTech service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

### How can I tell if this product suits my needs?

When making a choice, we recommend paying attention to the key features: internal, host interface, output interface, compatibility with your devices or usage conditions, material quality, functionality, and warranty terms. These characteristics will help you determine how well the model meets your needs.

### Where can I download the instructions for StarTech.com PEX1S553LP interface cards/adapter PEX1S553LP?

You can download the instructions in PDF format from the “Instructions” section on the product description page. The file contains complete information about installation, setup, and usage.

## Image

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