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Green PCB card with four serial ports on a breakout cable and two metal brackets

STARTECH

STARTECH PEX4S232485 4-port PCIe serial expansion card

SKU CH-ZQJ6-4KFJA MPN PEX4S232485

Adds two RS232 and two RS422/485 serial ports via PCI Express with 460.8 Kbps max baud rate and 256-byte FIFO

  • TypePCI Express to Serial Port Card
  • External Ports2 x RS232 2 x RS422 / RS485
  • Operating Systems SupportedWindows 8 (32/64bit), 7 (32/64), Vista(32/64), XP(32/64), 20
  • SpecificationsData Bits: 5, 6, 7, 8 FIFO: 256 Bytes Flow Control: None, Xo
  • Features4 port (2 x RS232, 2 x RS422/485) serial combo card RS232 da
  • Dimensions0.6" x 2.7" x 5.3"
  • Add two RS232 and two RS422/485 ports via a PCI-Express slot
  • RS232 data rates up to 460.8 Kbps for fast serial communication
  • Supports 2-wire and 4-wire RS485 modes for flexible industrial use
  • 256-byte FIFO per port reduces CPU overhead during data transfer
  • Includes standard and low-profile brackets for versatile chassis fit

Four-port PCIe serial combo card

This card adds two RS232 ports and two RS422/485 ports through a single PCI Express slot. It suits engineers, integrators and technicians who connect legacy industrial, laboratory or point-of-sale equipment to modern PCs. The board ships with a breakout cable and both standard and low-profile brackets for flexible mounting.

Upgrades motherboards lacking native serial I/O

Many current boards omit DB9 headers entirely, so this adapter restores direct hardware serial links without USB converters. The jump is worth it when software requires true COM ports, deterministic timing or multi-drop RS485 networks that USB-to-serial cables cannot reliably provide. Supported data rates reach 460.8 Kbps with 256-byte FIFO buffers per channel.

Verify an open PCIe slot and OS driver support

Confirm the system has a free PCI Express slot compatible with the 1.0a specification used by this card. Check that the target operating system appears in the supported list, which includes Windows versions from 2000 through 8 and Linux kernel 2.6.x. The package includes a driver CD and manual for installation.

Highlights

  • Add two RS232 and two RS422/485 ports via a PCI-Express slot
  • RS232 data rates up to 460.8 Kbps for fast serial communication
  • Supports 2-wire and 4-wire RS485 modes for flexible industrial use
  • 256-byte FIFO per port reduces CPU overhead during data transfer
  • Includes standard and low-profile brackets for versatile chassis fit

Specifications

BrandStarTech.com
ModelPEX4S232485
TypePCI Express to Serial Port Card
External Ports2 x RS232
2 x RS422 / RS485
Operating Systems SupportedWindows 8 (32/64bit), 7 (32/64), Vista(32/64), XP(32/64), 2000
Windows Server 2008 R2, 2003(32/64)
Linux Kernel 2.6.x
SpecificationsData Bits: 5, 6, 7, 8
FIFO: 256 Bytes
Flow Control: None, Xon/Xoff, RTS/CTS
Max Baud Rate: 460.8 Kbps
Parity: None, Odd, Even, Space, Mark
Serial Protocol: RS-232/422/485
Stop Bits: 1, 1.5, 2
Supported Protocols: RS-232, RS-422, RS-485 2-wire / 4-wire
Features4 port (2 x RS232, 2 x RS422/485) serial combo card
RS232 data transfer rates up to 460 Kbps
Supports 2-Wire / 4-Wire RS485 modes
256-byte deep FIFO per transmitter and receiver
Standard and low-profile bracket included
Compliant with PCI-Express Specification 1.0a
Supports PCI Power Management 1.1
Dimensions0.6" x 2.7" x 5.3"
Weight2.4 oz.
Package Contents1 - PCI Express Serial Combo Card
1 - Breakout Cable
1 - Low Profile Bracket
1 - Driver CD
1 - Instruction Manual
Shipping weight0.39 kg
Package size210 × 150 × 40 mm

Questions about this item

Will the low-profile bracket let me install this card in a 2.7-inch high slim chassis?

The card measures .6 by 2.7 by 5.3 inches and includes both a standard and a low-profile bracket so it fits either full-height or slim cases.

Which PCIe slot version is required and how is the breakout cable attached?

The card uses a PCI-Express 1.0a slot; plug the card in, then connect the supplied breakout cable to the on-board header to access the four DB-9 ports.

What RS-485 wiring modes are supported and do they need jumper changes?

The two RS-422/485 ports support both 2-wire and 4-wire RS-485 modes, configurable through the driver software without hardware jumpers.

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