LPCI-COM422-8 and LPCI-COM485-8

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  • Universal PCI, PCI-X, 3.3V and 5V compatible (Call for PCI-Express availability)
  • Eight-Port, RS-422 or RS-485 protocols
  • Speeds up to 921Kbps
  • Include type 16550 UARTs (optional 16850)
  • Meets MD2 Low Profile PCI Bus Specification
  • Breakout cable provides DB9 connectors for each port (no external breakout box required)
  • RoHS Available. Please contact us for ordering information
  • Designed, made, supported, and manufactured in the USA
  • Support for Wind River VxWorks (call for ordering information)
Last updated on November 2, 2023, 6:25 pm


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Universal PCI, RS-422 or RS-485 Serial Interface Cards (In a Low Profile form factor)

These are eight-port, asynchronous, serial communication cards designed for use on the PCI bus. They support RS-422 or RS-485 communications. These cards offer the best combination of high-density and high-speed communications in a low profile form factor. The cards meet the MD2 Low Profile PCI Bus Specification and can be used in applications where space is at a premium, such as thin-client servers and high-density rack-mount servers. The LPCI line has been designed for use in retail, hospitality, and point of sale systems as well as the gaming and defense industries.

The cards are 6.6 inches in length and 2.21 inches in height and may be installed in any available 3.3 or 5V PCI or PCI-X expansion slot. Normally, these units are supplied with an eight-connector breakout cable (no external breakout box required). However, they are available without that cable as models LPCI-COM422-8S1 and LPCI-COM485-8S1 for OEMs that fabricate their own cable harnesses.

Type 16C550 UARTS are used as the asynchronous communication elements. These include a 16-byte transmit/receive FIFO buffer to protect against lost data in multitasking systems while maintaining 100% compatibility with the original IBM serial port. ACCES also offers16850 UART functionality as an option to lower the CPU loading and allow for error-free data communications even at high simultaneous data rates.

Crystal oscillators located on the cards permit precise baud rate capability up to 115,200. Higher baud rates, up to 921,600 baud, are achieved by changing a jumper on the card. The driver/receivers used, type SN75176B, are capable of driving long communication lines at high baud rates. They can drive up to ±60 mA on balanced lines and receive inputs as low as 200 mV differential signal superimposed on common mode noise of +12 to -7V. In case of communication conflict, the driver/receivers feature thermal shutdown.

Since these are PCI-Bus cards, the operating system determines the resources assigned to the card. As a result, you cannot set or change the card’s base address. You can only determine what the system has assigned. The PCI Bus supports 64K of I/O bus address space so your card’s address may be located anywhere in the 0000 to FFFF range.


In RS-485 communications, the driver must be enabled and disabled as needed, allowing all cards to share a two wire cable. The LPCI-COM485-8 card controls the driver automatically. With automatic control, the driver is enabled when data is ready to be transmitted. The driver remains enabled for one additional character’s transmission time after data transfer is complete and then is disabled. The receiver is also normally enabled, then disabled during RS-485 transmissions, and then re-enabled after transmission is completed (plus one character transmission time). The LPCI-COM485-8 automatically adjusts it’s timing to the baud rate of the data. (NOTE: Thanks to the automatic control feature, the card is ideal for use in WIN9x/NT/2K/XP applications)


A complete driver support package is provided including an easy to use Windows terminal program for testing out your COM ports. This helps simplify verification of proper operation. The card installs as standard Windows COM ports in all Windows operating systems including the ability to re-direct the starting COM port number at COM3 in Windows NT 4.0. The card is supported by most operating systems and includes a free DOS, Linux and XP -> 10, both 32 & 64 bit compatible software package. This includes sample programs and source code in “C” for DOS, and Visual Basic, Delphi, and Visual C++ for Windows. Also included is a graphical setup program in Windows.




Drivers and Downloads

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

Information about our Free Software packages:

ACCES is proud to provide a full suite of software support with every Data Acquisition product. We are committed to supporting the most popular operating systems and platforms for our customers. Currently we are actively supporting XP -> 10, both 32 & 64 bit, including “Server 2008,” “Embedded,” and “Compact” flavors for all plug-and-play products including PCI, PCI Express, USB, and more. Many products continue to ship with support for additional operating systems such as DOS, Windows 95, 98, Me, NT4, and 2000.


Among the software we deliver with our products are sample programs in a wide variety of programming languages. These samples are used to demonstrate the software interfaces to our products — and many can be used as-is in your production environments, or to test functionality of the devices out-of-the-box. We’re currently actively supporting sample programs in Microsoft Visual C#, Visual Basic, Delphi, and Visual C/C++, with many devices including samples in Borland C/C++ 3.1 for DOS. Additionally we provide National Instruments LabVIEW compatible DLLs and many demonstration VIs for our devices.


Drivers for various operating systems are also provided, including active support for Windows XP -> 10 — all in both 32-bit and 64-bit flavors, and including consumer, server, and embedded varieties — as well as the 2.6 and newer Linux kernels and recent OSX / macOS versions. Many products continue to ship with driver support for Windows 95, 98, Me, NT4, and Windows 2000, but support for these operating systems is considered deprecated.

Setup Programs and Utilites

Our Data Acquisition devices also include a graphical setup utility that walks you through the process of configuring any option jumpers or switches on the device, as well as explaining a little about the various connectors present.

Many devices also include utility programs – little tools to make your use of the device easier, such as EWriter, a program that allows you to read and write data in the user-accessible EEPROM locations on all our USB data acquisitition products; or WinRISC, a “Really Incredibly Simple Communications” terminal program that lets you get started instantly with serial devices.

“Register Level” Documentation

Besides all this software in all these languages and operating systems ACCES has a policy of open and transparent development: none of our lowest-level “register” interfaces are hidden from you — we document every register in every bus card, every command in every serial board, and every usb control transfer in every USB Data Acquisition board. These lowest-level interfaces allow you to develop for our products in ANY operating system or language, regardless of our actively supporting it or having a driver for it. We have customers actively developing in ADA, Android, Python, Java, MATLAB, Solaris, and more, just by referring to our complete low-level interface documentation! And we provide the full source code to all of our drivers, regardless of operating system, to give you an even bigger head start in your own development tasks.

No Fees or Royalties

All of this software is provided at no additional charge, and is licensed under any of a variety of flexible — and royalty free — options. Check out our software license explanation if you’d like more information.

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: Via a 50-pin, shielded, SCSI-2 connector. There are 2 pins per port plus common grounds shared by pairs of ports for the RS-485 version, and 4 pins per port plus common grounds shared by pairs of ports for the RS-422 version.
  • Cable: Breakout Cable from SCSI-2 Connector features one-touch-lock-latches, with Eight-DB9 connectors.
  • Character length: 5, 6, 7, or 8 bits.
  • Parity: Even, odd or none.
  • Stop Interval: 1, 1.5, or 2 bits.
  • Serial Data Rates: Up to 115,200 baud, asynchronous. A faster range of rates, up to 921,600, is achieved by jumper selection on the card prior to installation.
  • Multidrop:
    • LPCI-COM485-8: Compatible with RS-485 specifications. Up to 32 drivers and receivers allowed on line. Drivers/Receivers used are type SN75176B.
    • LPCI-COM422-8: Compatible with RS-422 specifications. Up to 10 receivers allowed on line.
  • Address: Continuously mappable within 0000 to FFFF (hex) range of PCI Bus range of addresses.
  • Receiver Input Sensitivity: ±200 mV differential input.
  • Common Mode Voltage Range: +12V to -7V
  • Transmitter Output Drive Capability: 60 mA, with thermal shutdown.


  • Operating Temperature Range: 0° to +60°C
  • Storage Temperature Range: -50° to +120°C
  • Humidity: 5% to 95%, non-condensing.
  • Power Required: +5VDC at 200 mA typical, 1300 mW total power consumption.
  • Size: 6.6″ long (167.64mm) by 2.21″ tall (56.17mm) seated height.

Regulatory Compliance

  • This product is in full compliance with CE requirements.
ModelDescriptionPrice (USD)

Universal PCI, RS-422 Serial Interface Card (In a Low Profile form factor), No Cable


Universal PCI, RS-422 Serial Interface Card (In a Low Profile form factor) Cabled DB9Ms


Universal PCI, RS-485 Serial Interface Card (In a Low Profile form factor) No Cable


Universal PCI, RS-485 Serial Interface Card (In a Low Profile form factor) Cabled DB9Ms