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104-COM232-8 Series

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Eight, Four, and Two-Port RS-232 Serial Communication


  • 8, 4 or 2 RS-232 asynchronous serial COM ports
  • Speeds up to 230.4K with 64-byte FIFO
  • Programmable IRQ sharing simplifies system design and installation
  • Low power required: 5VDC at 80mA typical
  • Operates as a standard COM port in all operating systems
  • Factory Options: (call for pricing and availability)
    • 128-byte FIFO
    • 0 to 70°C and -40 to 85°C versions available

This is an eight, four, or two-port, asynchronous, serial communication board designed for use on the PC/104 bus. It supports full RS-232 serial communications. The board may be installed in any standard PC/104 stack. Connections are made via two 40 pin IDC type right angle connectors for the boards optional breakout cable. The boards are feature-rich and allow for the connection of multiple serial devices—ideal for a variety of applications such as POS, barcode readers, modems, machine monitoring and control, military, high-density networking applications or any other application requiring the connection of RS-232 serial devices to a PC/104 compatible system.

Type 16780 UARTS are used as the asynchronous communication elements. These include 64-byte transmit/receive FIFO buffers to protect against lost data in multitasking systems while maintaining 100% compatibility with all operating system COM port drivers. ACCES offers the 104-COM232-8 series in both standard and extended temperature versions ideal for outdoor applications or harsh industrial surroundings. Ordering options include UARTs with larger FIFOs, support for custom baud rates, vertical I/O pins, and custom cabling.


A crystal oscillator located on the board permits precise baud rate capability up to 230.4K. The addresses of the individual channels and IRQ are stored in non volatile memory on the board and loaded into programmed logic when the board is initially powered.



The 104-COM232-8 series are supported by most operating systems and include a free DOS, Linux and Windows 95/98/Me/NT/2000/XP/2003 compatible software package. This includes sample programs and source code in "C" and Pascal for DOS, and Visual Basic, Delphi, C Builder, and Visual C for Windows. Also included is a graphical setup program in Windows. An easy-to-use Windows terminal program simplifies verification of proper operation (also provided in a DOS version.)


Communications Interface

  • I/O Connections: Via two 40 pin IDC type right angle connectors. There are eight pins per port plus common grounds.
  • 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 230.4K baud, asynchronous.
  • Common Mode Voltage Range: 12V to -7V
  • Base Address Options: Programmable
  • Interrupts: Shared IRQ is programmed and stored onboard in non-volatile memory


  • Short Circuit Protection: All outputs are protected against continuous short circuit
  • Power Required: 5 VDC at 80 mA typical, all outputs open
  • Operating Temperature: 0 to 70°C, (-40 to 85°C Optional)
  • Storage Temperature Range: -50 to 120°C
  • Humidity: 5% to 95% RH, non-condensing
  • PC/104 bus 8-bit and 16-bit bus headers are used

CE testing & approval must be done at the system level, in the designed enclosure, and is not done on individual boards.

Part NumberPrice(USD)
View / Download Data Sheet (in .pdf format)

View / Download Manual (in .pdf format)
Acquisition Control Communications Engineering / Systems
USA Office

Address: 1480 Gulf Road, Suite 837,
PO Box 1364
Point Roberts, WA 98281

Western Canada - Vancouver BC

Tel:1.800.663.6001 or 1.604.925.6150
Address: 2454 Haywood Ave
West Vancouver, BC V7V 1Y1

Eastern Canada - Markham, Ontario

Tel:1.800.465.0164 or 1.905.513.7027