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Green PCB expansion card with four DB9 serial ports on a metal bracket

STARTECH

STARTECH PEX4S953 4-Port PCIe RS232 Serial Card 16950 UART AX99100

SKU CH-X6RA-HFZK7 MPN PEX4S953

Adds four RS232 serial ports via a PCIe slot with 16950 UART and per-port power options

  • Adds four RS232 DB9 ports via PCIe 1.1 slot
  • Each port reaches 921.6 Kbps with 16950 UART and 256-byte FIFO
  • Pin 9 supplies 5 V or 12 V up to 2 A total, set per port
  • Includes full-height and low-profile brackets for any chassis
  • Works with Windows XP onward and Linux kernels

Four RS232 Ports on PCIe

This StarTech PEX4S953 adapter adds four DB9 serial ports through a single PCI Express slot, using the ASIX AX99100 controller and 16950 UART. It targets administrators and engineers who need to connect legacy serial equipment such as PLCs, scientific instruments or point-of-sale hardware to modern servers or workstations.

Fits Standard and Low-Profile Builds

The card ships with a full-height bracket installed and includes a low-profile bracket for compact chassis. A DB44-to-4×DB9 breakout cable is supplied, and each port can be individually configured to deliver 5 V or 12 V on pin 9 up to 2 A total when auxiliary power is connected.

Replaces the PEX4S952 Model

This 953 revision supersedes the earlier 952 card while keeping the same four-port layout and 921.6 Kbps per-port throughput. The upgrade is worthwhile when broader OS support or the revised AX99100 implementation is required for current Windows and Linux deployments.

Highlights

  • Adds four RS232 DB9 ports via PCIe 1.1 slot
  • Each port reaches 921.6 Kbps with 16950 UART and 256-byte FIFO
  • Pin 9 supplies 5 V or 12 V up to 2 A total, set per port
  • Includes full-height and low-profile brackets for any chassis
  • Works with Windows XP onward and Linux kernels

Specifications

No published specifications for this item yet.

Questions about this item

What is the maximum sustained baud rate per port?

Each of the four DB9 ports supports bi-directional RS232 speeds up to 921.6Kbps with a 256-byte FIFO buffer per transmitter and receiver.

How much power can the card draw through pin 9 during continuous operation?

The card provides configurable 5V or 12V output on pin 9 with up to 2A total current when external power is connected to the DB44 breakout cable.

Which bracket must already be on the chassis for a standard-profile installation?

The card ships with a standard-profile bracket pre-installed and includes one low-profile bracket for alternative form factors.

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