TABLE OF CONTENTS In many areas, the testing of telecommunication networks is moving rapidly toward a system environment. One example of this trend can be seen in the operational maintenance of FDM networks (Chapter 7) where, since the mid-70s, there has been a significant shift toward centralized maintenance systems with many monitoring sites reporting the results of measurements into a network-control center. Such systems cannot function unless the individual elements instruments, computers, and peripherals can communicate effectively with one another. There must be a way to tell an instrument (for example, a SLMS) what to do (measure the level of mastergroup pilot 1) and when to do it. There must also be a way for an instrument to tell what it has accomplished (level is ?53.4 dBm). This communication, or transfer of information, is accomplished via some form of interface. Although many forms of interface have been developed over the years, one interface in particular has recently gained acceptance as a standard for instrumentation. This is the IEEE Standard 488 1978, Digital Interface for Programmable Instrumentation. Because most telecommunications test products aimed at the systems market that have been developed since the mid-70s use this interface, it is worthwhile gaining an understanding of its capability and operation, even if only in broad terms. A condensed description of the interface is provided in this appendix; however, any reader wishing to gain a more detailed understanding should read the references given at the end...
