Chapter 8 - Standard Hardware Interfaces

Abstract

This chapter focuses on the common PC hardware interface standards including general-purpose interface bus (GPIB), EIA RS–232C, and universal serial bus (USB). A standard hardware interface is used either by another computer or by an external peripheral device. In general, digital computer interfaces divide into two categories: parallel and serial. The parallel interface transfers data n times faster than the serial interface. The serial interface consists of only one data line and one or more control lines. Another common parallel interface used for data acquisition is GPIB. This interface connects computers to their programmable instruments. GPIB was designed to connect multiple peripherals to a computer or other controlling device. The GPIB uses a master-slave protocol for data transfer. Needless to say, the EIA RS-232C interface is the oldest and most common serial interface used by computer equipment. The RS-232C interface supports several handshaking lines. This is not an interlocking handshake as used in GPIB for control of data flow. Today, the PC industry leaders have developed the USB as a replacement for standard serial and parallel ports on a PC. USB is a high-speed serial bus with data rates as high as 12 Mbits/sec.