TABLE OF CONTENTS Two possible methods of transmitting digital measuring data, and, generally speaking, digital data, are serial transmission and parallel transmission. Serial transmission consists of transmitting a sequence of bits, bit-by-bit, according to the timing signals of a system clock synchronizing the transmission. Parallel transmission, on the other hand, consists of transmitting a sequence of words, usually 8-bit words (as in the IEEE-488 interface system), word-by-word, according to the timing (synchronization) signals. The mode of data transmission, serial or parallel, is the basic criterion of classifying computer measurement systems into measurement systems with serial interface or measurement systems with parallel interface. Computer measurement systems with serial interface are used to set up a simple measurement system, or to create a distributed measurement system. A distributed measurement system may be composed of measuring devices set up in a system by means of modems and a wire transmission network (telephone network) or a wireless network.
Chapter 6 is devoted to wired measurement systems with a serial interface. The structure and organization of an RS-232 system are described in Section 6.2. Section 6.3 is devoted to programming of measurement systems with RS-232. Two examples of software are presented and discussed in this section. Distributed measurement systems with RS-232 interface and a modem are presented in Section 6.4. Other recommended standards of serial interface (e.g., RS-422A, RS-423A, or RS-485) are introduced in Section 6.5. PROFIBUS and CAN systems, both very important for industry applications, are presented in Section 6.6. In...
