Specifications

University of Hertfordshire
19
Chapter Four: COMMUNICATION
This chapter will describe two different communications in the project. One is the
communication between server and the Spectrum Analyser, the other is the
communication between server and client.
4.1 Overview
To control the Spectrum Analyser from client via the Internet, there are two types of connection
need to be concerned. Client make a TCP/IP connection to server, once the connection has built,
client can send control message to the server. When server received the message comes from the
client, it will send these commands to the Spectrum Analyser thought IEEE 488.2 GPIB connection
as a format that the Spectrum Analyser can read. Next, these two connections will be introduced
respectively.
4.2 Communication between server and the Spectrum Analyser
Figure 4.1 IEEE 488.2 GPIB connection between Linux and the Spectrum Analyser (Programmer’s
Guide, 1995)
4.2.1 Introduction to GPIB
In 1965, Hewlett-Packard Interface Bus (HP-IB) was designed by Hewlett-Packard, and was
designed to connect their line of programmable instruments to their computers. This interface bus