Log In

Celebrating 43 Years

Follow us on Facebook for all the latest news, updates and promotions


Credit Cards Accepted
Thomas Supplier



pcl-740 image

1-port RS-232/422/485/Current-Loop Card with 16C550 UART


Ordering Information

Introduction Return to top of page

The PCL-740 offers a versatile range of high speed interfacing options. You can switch its single port between popular RS-232, long distance RS-422, multidrop RS-485, or noise-resistant current-loop. The card's 16C550 UART has an on-chip 16-byte FIFO buffer for faster and more reliable communication, especially under Windows.

The PCL-740 comes with a communication software package called PC-ComLIB. The package consists of a configurable DOS driver, a programming library that supports most common languages (such as C, Pascal, Visual Basic, assembly and Clipper) and DataScope. DataScope is a data viewer/ terminal emulator with self-diagnostics utilities for easy troubleshooting and debugging.

The RS-485 mode automatically senses the direction of incoming data and switches its transmission direction accordingly. This feature means your network looks and acts just like an RS-232 network. Moreover, you can simply and quickly build an RS-485 network over two wires. Application software written for half duplex RS-232 can be used without modification.

Applications Return to top of page

  • Instrument controller, distributed control systems
  • Interface to modem, bar code reader, scale, plotter feed and serial links for PCs and instruments
  • PLC monitoring and control
  • Data entry terminals
  • Remote data acquisition and control

Features Return to top of page

  • RS-232, RS-422, RS-485 or current-loop interface
  • 16C550 UART with 16-byte FIFO
  • Transmission speeds up to 115 Kbps
  • Flexible I/O address and IRQ selection
  • IRQ: 3, 4, 5, 6, 7, 9, 10, 11, 12 or 15
  • Complete RS-232 modem control signals
  • Supports 2 wire or 4 wire operation for RS-422/485
  • Automatic RS-485 data flow control
  • Space reserved for termination resistors
  • Supports COM1, COM2, COM3, or COM4
  • PC-ComLIB software included

Specifications Return to top of page

  • Number of Ports: 1
  • Protocol: RS-232, RS-422/RS-485 or current-loop
  • UART: 16C550 with 16-byte FIFO
  • I/O address: From 200H to 3F8H
  • IRQ: 3, 4, 5, 6, 7, 9, 10, 11, 12 or 15
  • Data bits: 5, 6, 7, 8
  • Stop bits: 1, 1.5, 2
  • Parity: Even, odd or none
  • Power consumption:
    5V@180 mA max. ,
    12V@20 mA max.
  • Connectors: DB-9 male and DB-25 male connectors
  • Operating temperature: 32 to 122 degF (0 to 50 degC)
  • Dimensions: 7.25" x 4.13" (185 mm x 100 mm)
  • Shipping weight: 0.44 lb. (0.2 Kg)


Ordering Information Return to top of page


RS-232/RS-422/RS-485/Current-loop Serial Interface Card. Includes PC-ComLIB software.
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