ACCES I/O Products supports critical infrastructure as defined by the US Department of Homeland Security and will be open during normal business hours 6 AM to 6 PM to serve our customers.
We are here to support you.

PCIe-COM232-8 & PCIe-COM232-4

Low Profile PCI Express Multi-Port Serial Communication Cards


  • Eight or four-port PCI Express RS-232 serial communication cards
  • Low profile PCIe MD1 form factor, MD1 defines the shortest standard card length available
  • High performance 16C950 class UARTs with 128-byte FIFO for each TX and RX
  • Supports data communication speeds up to 921.6kbps (standard model 460.8kbps)
  • ±15kV ESD protection on all signal pins
  • Full modem control signals
  • Software compatible with all operating systems
  • Plug and Play, no jumpers to configure
  • 3’ breakout cable included, terminating with industry standard DB9M connectors (no external breakout box required)
  • Designed, made, supported, and manufactured in the USA


  • Connector strengthening bracket for secure and fail-proof connections
  • Extended temperature (-40°C to +85°C)
  • High speed version up to 921.6kbps
  • RoHS compliant version
  • Support for Wind River VxWorks (call for ordering information)
  • Remote wake-up enable
  • Low profile bracket installed for small, embedded PCs

ACCES I/O’s PCI Express multiport serial communication cards deliver eight (PCIe-COM232-8) or four (PCIe-COM232-4), high-speed, RS-232 ports for use in a wide variety of applications. The cards were designed to offer serial compatibility with the PCI Express bus and to be used by system integrators and manufacturers in the design of industrial and commercial systems. Each RS-232 port is capable of supporting data rates up to 921.6kbps and implements full modem control signals to ensure compatibility with a broad variety of serial devices. Existing serial peripherals can connect directly to the industry standard DB9M connectors which are provided on the breakout cable that ships with each card. The card features a x1 lane PCI Express connector which can be used in any available x1, x2, x4, x8, x12, or x16 PCI Express expansion slot.

The card is 4.7 inches in length and 2.2 inches seated height and complies with the MD1 Low Profile Form Factor specifications (the smallest PCI Express card available). Low profile PCI Express allows the design of small footprint, low profile systems while still offering expandability and upgradeability to the end user. A regular profile mounting bracket is installed for use in standard size computers, while a low profile bracket is provided for smaller systems which require the use of low profile PCI Express cards.

Available accessories include a broad range of cables, screw terminal boards and breakout connection boxes for a variety of quick and easy connectivity options.


Custom baud rates are available upon request. Please contact ACCES with your precise requirement. Other examples of special orders would be conformal coating, custom software, RJ45 connectivity, special breakout boxes, etc… we will work with you to provide exactly what is required.


A complete driver support package is provided including an easy-to-use Windows terminal program for testing out your COM ports. This simplifies the verification of proper COM port operation. The card installs as standard COM ports in all operating systems including DOS, Linux (including Mac OS X) and Windows XP -> 10, both 32 & 64 bit.

Available Reference Manuals

Available Software Downloads

Available Datasheets

Drivers and Downloads

Full list of available Downloads: Software Packages, Drivers, Manuals, and other documents

Custom Software

ACCES also offers Custom Software Services for our products. Our prices are unbelievably low, often as inexpensive as free! If you need something tweaked to support your needs, or an entire enterprise application developed from scratch, it is definitely worth your time to inquire with us, first.

Further information about available ACCES Software:

Redistributing Windows Drivers
A list of ACCES drivers and the files that compose them under different versions of Windows, so you can easily redistribute ACCES cards and drivers.


ACCES has successfully partnered with Wind River to bring our entire line of PCI and PCI Express Serial Communication cards to VxWorks 7! All ACCES plug-and-play serial cards are now supported with our VxWorks driver, including RS232, RS422, RS485 (2- and 4-wire) and baud rates up to 10Mbps.

Designed as an update to the existing vxbPciNs16550Sio.c driver, we've added support for ×8 baud rates, proper handling of the unique register location of the 4th port in the Pericom PI7C9X7954 UART, and configuring the serial protocol from your application software.

With this driver suite all ACCES PCI, PCI Express, PCI Express Mini Card, M.2, PCI-104, PCIe/104, and all related "PCI Style" plug-and-play serial cards will detect and install as standard VxWorks SIO ports.

Communications Interface

  • I/O connection: VHDCI 68 pin SCSI connector
  • Serial ports: 8 RS-232 ports
  • Serial data rates: 460.8k baud (up to 921.6k baud) asynchronous
  • UART: Octal type 16C950 with 128-byte transmit & receive FIFO, 16C550 compliant
  • ESD Protection: ±15kV on all signal pins
  • Character length: 5, 6, 7, or 8 bits
  • Parity: Even, Odd, None, Space, Mark
  • Stop interval: 1, 1.5, or 2 bits
  • Flow Control: RTS/CTS and/or DSR/DTR, Xon/Xoff
  • Cable: 3’ shielded breakout cable terminated with 8 male D-sub 9-pin connectors


  • Operating Temperature Range: Commercial 0° to 70°C; Industrial -40° to +85°C
  • Storage Temperature Range: -65° to +150° C
  • Humidity: 5% to 95%, non-condensing.
  • Board Dimension: 4.72" (120mm) long by 2.20" (55.8mm) high


  • +3.3VDC @ 0.9W (typical)

OEM and volume pricing available, please call us.  

ModelPrice (USD)

Ordering Guide
PCIe-COM232-8PCI Express eight-port RS-232 serial card with 3’ DB9M breakout cable
PCIe-COM232-8NCPCI Express eight-port RS-232 serial card without cable
PCIe-COM232-4PCI Express four-port RS-232 serial card with 3’ DB9M breakout cable
PCIe-COM232-4NCPCI Express four-port RS-232 serial card without cable
BRKT-551-SCBConnector stabilizer bracket (for use with standard height PCIe bracket only) $19
ADAP9Screw terminal adaptor (single DB9 female to 9 screw terminals)
ADAP9-2Screw terminal adaptor (dual DB9 female to 18 screw terminals)
Model Options:
-F Fast version (up to 921.6kbps)
-T Extended temperature (-40°C to +85°C)
-RoHSRoHS compliant version
-W Wake-up enabled version
-L Low profile bracket installed

Acquisition, Control, Communication: Engineering and Systems