Thesis (M.Diploma in Technology)--Cape Technikon, 1993 / This thesis describes the development of a 5-Tone Zentral Verband Electrotechische Industrie eZVEI) Encoder Analyser. The 5-Tone ZVEI Encoder Analyser is used by the Radio Section of the Test and Metering Branch, which falls under the Electricity Department of the Cape Town City Council. It assists the Quality Assurance Technician in determining whether the 5 tone ZVEI encoder, of the radio under test, is operating within the manufacturers specifications. Various manufacturers of radio equipment tender for the supply of mobile radios fitted with ZVEI tone The Radio Section are now capable of testing encoders. all the various radios and comparing the analysed ZVEI specifications of each manufacturer's radio. The results can be used to assist management in deciding which radio would be the most suitable for purchasing. The development of the 5-Tone ZVEI Encoder Analyser involved the design and development of hardware and software. It was designed to be housed in a compact enclosure and to interface to a Motorola Communications System Analyser Model R-2001C. The RF output, from the radio under test, connects to the RF input of the Communications System Analyser. The demodulated output of the Communications System Analyser connects to the input of the 5-Tone ZVEI Encoder Analyser. The softwa~e was designed using PLM-51 high level language to p~ovide ~eal-time analysis of va~ious selective-calls (selcalls) ~eceived f~om the demodulated output of the Communications System Analyser. Once all 5 tones of the ZVEI selcall have been analysed the software background task is flagged and the analysed results a~e displayed as various MODES of display on a 16 cha~acte~ by 4 line dot matrix display. The following parameters of the ZVEI selcall a~e analysed: i) Frequency Digits. ii) Frequency fo~ each of the 5 tones. iii) Tone Duration for each of the 5 tones. iv) Frequency Error for the 5 tones. v) Tone Duration Er~or for the 5 tones. The design and development of the 5-Tone ZVEI Encode~ Analyser was conducted at the Computer Section of the Electricity Depa~tment, Cape Town City Council.