RS-232 specs
The serial UART
I/O and IRQ's
Flow control
Which null modem?
Software download

Cables for data interfacing

Even in this era of wireless communications, cables are still the most used method to connect computers and peripherals. Several different protocols and cables are used to communicate and each has its specific properties. These pages contain a detailed explanation for the most used cables with in many cases a layout to build the cable yourself.
RS232 cables are used to connect devices that communicate using the RS232 protocol. This interface definition is already more than fourty years old, but it is still used in many applications. Specifically situations where cheap communications is necessary at a moderate speed over longer distances, this interface is often the first choice. The common pinout is shown for DB9 and DB25 connectors and also many wiring schemes are present for several applications.

Modular cables are mostly known from computer networks based on UTP and FTP cables. This is however not the only application of modular cables. Also analog and ISDN telephone connections are often wired with modular cables and Digital Equipment Corporation defined in the past a data cable system based on modular cables with the name DECConnect.

Parallel cables are historically mainly used to connect printers to computers. The seven or eight parallel data lines ensure a fast data exchange which is important when large print jobs are processed. The parallel interface is however also capable for two-way communication and specifically for this purpose the Interlink or Laplink cable has been developed. This cable makes it possible to exchange data between computers if the right software is used. Layouts for the regular printer cable and the Laplink cable are present on these pages.

PLC cables are used to connect industrial controllers with computers and peripherals. There is a huge mess of cable layouts around, because almost every manufacturer decided to define its own wiring scheme for a specific situation. The layouts for the most used cables are shown on these pages.

When in doubt,
predict that the trend will continue.
   Lammert Bies     Interfacing     Sitemap     Forum 
 EN   NL