Design of digital communication module for remote measurement systems

In this paper are presented the results obtained in the design and implementation of an improved communication module intended to be used in a remote measurement and data acquisition system that operate in industrial environments. The module is composed by two sections, a digital modulator and a synchronous demodulator with carrier recovered from the incoming data stream. The proposed module can realize bidirectional communications and is capable to operate with two modulation techniques: PSK (phase shift keying) and ASK (amplitude shift keying). The novelty of the proposed module consists in the reliable implementation which is based on efficient shift keying transmission techniques. This lead to a higher immunity to electrical noises and spurious signals which are very characteristic to measurements systems that operates in industrial environment. Also, the proposed architecture of the communication module is suitable for transmission of multiplex data strings which allows multiple sensors integration in a multipoint measurement system.