Startech.com Low Profile RS232 PCI Express Serial Card PEX16S952LP User Manual

StarTech.com Low Profile RS232 PCI Express Serial Card PEX16S952LP Manual

The startech.com Low Profile RS232 PCI Express Serial Card PEX16S952LP expands one PCI Express slot into 16 independent RS232 serial ports. It is designed for computers that need many legacy serial connections without installing multiple expansion cards, making it suitable for industrial control systems, point-of-sale equipment, automation hardware, scientific instruments, barcode scanners, and terminal devices.

This multi-port PCIe serial card uses a single PCI Express lane and connects to the included breakout cable through a high-density card connector. The cable provides 16 male DB9 connections for attaching standard RS232 peripherals. Its low-profile form factor suits compact desktop computers, rack-mounted systems, and other chassis with limited internal space; a full-profile bracket is also included for compatible standard-height cases.

With a maximum data rate of 921.6 Kbps and 128-byte transmit and receive FIFOs, the card is intended for reliable high-speed serial communication and reduced data loss during sustained transfers. The Oxford 16C950 UART design supports demanding applications that require multiple active serial ports at the same time.

This guide explains the card’s specifications, installation procedure, port configuration, connectivity requirements, and troubleshooting methods. Before installation, verify that the host computer has an available PCI Express slot and that the required operating-system driver is supported for the specific system.

PEX16S952LP Technical Specifications and Features

The following specifications describe the primary hardware capabilities of this 16-port RS232 PCI Express adapter.

• Product type: 16-port RS232 serial PCI Express expansion card
• Product ID: PEX16S952LP
• Bus interface: PCI Express revision 1.1, single-lane interface
• Serial protocol: RS232
• Serial ports: 16 DB9 male connectors through the included breakout cable
• UART: Oxford 16C950 high-performance serial architecture
• Chipset: PLX/Oxford OXPCIe958
• Maximum transfer rate: Up to 921.6 Kbps per serial port
• FIFO buffering: 128-byte transmit and receive buffers per port
• Card profile: Low-profile installation with a full-profile bracket included
• Cable: Multi-connector serial breakout cable included
• Operating temperature: 0°C to 55°C
• Storage temperature: -20°C to 85°C
• Relative humidity: 5% to 95%, non-condensing
• Typical applications: Industrial automation, legacy equipment, data acquisition, retail systems, and laboratory devices

Actual throughput depends on the connected equipment, cable quality, baud-rate settings, operating system, and serial communication protocol. RS232 is point-to-point, so each peripheral normally requires its own serial port and compatible cable.

How to Install the PEX16S952LP Low-Profile Serial Card

Step-by-step PCI Express installation

1. Shut down the computer, disconnect the power cable, and remove all attached peripherals.
2. Ground yourself to discharge static electricity, then remove the computer case cover according to the chassis instructions.
3. Locate an available PCI Express slot. Confirm that the slot and rear opening accommodate the selected low-profile or full-profile bracket.
4. Remove the blank expansion-slot cover and carefully insert the card into the PCI Express slot. Press evenly until the connector is fully seated.
5. Secure the card with the chassis screw. Do not force the board or bend the connector.
6. Attach the included breakout cable to the card’s high-density connector and secure it firmly.
7. Close the case, reconnect power, and start the computer.
8. Install the driver intended for the operating system and restart if prompted.

Port configuration and connectivity

After installation, open the operating system’s device manager and confirm that all serial ports appear without warning icons. Assign or verify COM-port numbers as required by the application. Configure each connected device with matching baud rate, data bits, parity, stop bits, and flow-control settings.

Use only compatible RS232 cables and avoid connecting or disconnecting equipment while the system is powered if the device manufacturer warns against hot-plugging. Keep the card and cable away from excessive heat, moisture, and electromagnetic interference.

PEX16S952LP Troubleshooting Guide

Card is not detected

Power off the computer and reseat the card. Test another compatible PCI Express slot if available, check that the card is secured correctly, and verify that the breakout cable is fully inserted. Remove conflicting or outdated serial-card drivers before installing the appropriate driver again.

Serial ports are missing or show warning symbols

Open Device Manager and inspect the serial-card entry. A warning symbol commonly indicates a driver, resource, or installation problem. Install the correct driver for the operating system, restart the computer, and check whether the ports appear under the expected COM-port category.

Connected equipment does not communicate

Confirm that the selected COM port matches the physical DB9 connection. Check the device manual for baud rate, parity, stop bits, data bits, and flow-control requirements. Verify that the cable uses the correct RS232 wiring and that the peripheral is powered on. If communication remains unreliable, try a shorter, shielded cable and test one device at a time.

Data is corrupted or lost

Reduce the baud rate temporarily, confirm matching communication settings, and enable the required hardware or software flow control. Avoid running serial cables alongside high-power electrical wiring.

Support and preventive maintenance

Keep the driver package, operating system, and application documentation available for future maintenance. For unresolved hardware, driver, or compatibility issues, use StarTech.com’s official product support, driver-download, FAQ, and warranty channels. Have the product ID, operating-system version, host-computer model, and troubleshooting steps ready when requesting assistance.

PEX16S952LP Pros and Cons

Advantages

• High port density: Provides 16 RS232 connections through one PCI Express slot, which is useful when a system must communicate with many legacy devices.
• Compact installation: The low-profile design fits small-form-factor and rack-mounted computers more easily than standard-height expansion cards.
• High serial speed: Supports data rates up to 921.6 Kbps, exceeding the maximum speed commonly needed by many traditional RS232 peripherals.
• Buffered communication: The 128-byte transmit and receive FIFOs help manage bursts of serial data and reduce processor overhead.
• Flexible chassis support: A full-profile bracket is included for systems that do not use a low-profile expansion opening.
• Single-slot design: A breakout cable delivers all 16 DB9 ports without occupying 16 separate rear expansion slots.

Limitations

• Legacy interface: RS232 is intended for point-to-point connections and is not a substitute for Ethernet, USB, RS485, or RS422 in applications requiring longer distances or multidrop networking.
• Cable management: Sixteen serial connections can create a substantial cable bundle in crowded workstations or control cabinets.
• Compatibility checking required: Driver availability and supported operating systems should be verified before deployment, especially on newer platforms.
• PCIe dependency: The card requires an available compatible PCI Express slot and cannot be installed in a conventional PCI slot.

The PEX16S952LP is best suited to industrial, commercial, and laboratory systems that require many simultaneous RS232 connections. Users needing only one or two ports, wireless connectivity, or long-distance multidrop communication may be better served by a smaller serial adapter or an RS485/USB-based solution.