ELECTRONIC INSTRUMENTATION CONFERENCE HOBART 1972 These papers have not been edited by the respective Institutions and no responsibility is taken for the views expressed. - CONTENTS - Computer Based Telemetry Systems for Remote Monitoring and Control R.A. Smythers, M.A., Senior Applications Engineer, Cutler-Hammer Australia Pty Ltd 1 Radio-Frequency Modulation and Demodulation of Lasers for Communication D.J. Cole, B.E.E.(Melb.), M.I.E.(Aust.), F.I.R.E.E., Principal Research Scientist. Division of Radiophysics, C.S.I.R.O., Sydney 9 An Instrumentation System for a Natural Gas Pipeline B.E. Richards, Fellowship Diploma of Electronic Engineering, Development Engineer, Relays Pty Ltd.... 16 Data Acquisition System for Astronomical Photoelectric Photometry D.G. Thomas, M.f.E.Aust, A.M.I.R.E.E.Aust, Engineer II, Mount Stromlo and Siding Spring Observatories, The Australian National University 22 Application of Solid State Logic in a Zinc Stacking Line Thomas Michael Fulton, B.E. (Elect) Uni. of NSW, Graduate I.E.Aust, Graduate I.E.E. London, Electrical Engineer, E.Z. Co. of A/asia Ltd, Risdon, Tasmania 29 Very Low Noise Amplifiers for Semiconductor X—Ray Detectors J.E. Eberhardt, B.E.(UQLD), M.E.(UNSW), Instrumentation and Control Division, Australian Atomic Energy Commission 38 A Telemetry System for Electrical Distribution Networks F. Zillhardt, Ing. (grad.). Senior Systems Engineer, Cutler-Hammer Australia Pty Ltd 45 Digital Companding Techniques C.J. Kikkert, B.E.(Hons.), Dept of Electrical Engineering, University of Adelaide, Adelaide, S.A 52 Vibration Technique for Rot Detection in Wood Poles A.D. Shaw, Dip.E.E., M.I.E.Aust., Development Engineer, Retail Supply Branch, Hydro-Electric Commission of Tasmania 57 Fault Detecting in a Processor-Controlled Telephone Switching System N.W. McLeod, B.Sc, M.I.E.(Aust), A/g Engineer Class 3, Australian Post Office Research Laboratories ... 65 Digital Phase Meter M. Imber, B.Eng.(Elec), University of Melbourne 74 A Computer Controlled Circuit Tester N.J. Gale, B.Eng. (Honours), Australian Post Office Research Laboratories, Melbourne 80 Technical Control Facilities for Common User Data Network Centres K.V. Sharp, A.R.M.I.T., Engineer Class 4, Postmaster-General's Department 80 An Accelerometer for Engines and Rotating Machines W.S. Leung, B.Sc., Ph.D., M.I.E.E., Sem.M.I.E.E., Senior Lecturer, University of Hong Kong; W.F. Ma, B.Sc. (Eng.), M.Sc.(Eng.), Lecturer, University of Hong Kong; and C.C. Lau, B.Sc., University of Hong Kong 90 Development of Telephone Traffic Measurement Equipment and it« Application in the Australian Telephone Network C.W. Pratt, Ph.D., Australian Post Office; and LA.Tyrrell, B.E., M.I.E.IAust), Australian Post Office 95 Metering Control and Alarm Indication for Power Rectifiers used in a large Electro-Chemical Zinc Plant M.J. Healy, B.E. (Uni. of Tas.), Grad.I.E.Aust., Electrical Engineer at The Electrolytic Zinc Company of Australasia Limited 104 A Direct Reading Digital Instrument for the Measurement of Speed of Road Vehicles G. Ganky, B.E., Grad.I.E.Aust., ').C.A., formerly Research Student, University of Melbourne: and A.E. Ferguson, M.E.E., M.I.E.Aust, F.I.R.E.E.Aust, Reader, University of Melbourne 112 Security of Supervisory Control Systems — Two Case Studies B.M. Lewis, B.Tech., M.I.E.Aust., Electrical Contracts Engineer, Control Systems. Electricity Trust of S.A. 117 A Presence and Passage Vehicle Detector G.F. Shannon, B.E., Ph.D., M.I.E.Aust, Senior Lecturer, Elec. Eng. Dept., University of Queensland; and N.V. Chuong, B.E., Research Assistant, Elec. Eng. Dept, University of Queensland 125 Digital Frequency, Time and Time Deviation Equipment J.W. Tamke, B.E.(Hons), Grad.!.E.Aust, M.I.I.C.A., Assistant Test Engineer, Power Electricity Trust of South Australia 129 Manipulators: An Instrumentation and Control Survey N. Newman, B.E., M.Eng.Sc, M. I.E.Aust; and K.E. Tait, B.E.(Hons). B.Sc., Ph.D., M.I.E.Aust Postgraduate Student and Senior Lecturer, Department of Control Engineering, School of Electrical Engineering, University of N.S.W 136 cc The Precise Measurement of Weak Magnetic Fields Ronald Green, B.Sc., Ph.D., A.M.I. R.E.E.; and John M.Stanley, B.Sc 142 Force-Feedback: A Review N. Newman, B.E., M.Eng.Sc, M.I.E.Aust, a post graduate student in the Dept of Control Engineering within the School of Electrical Engineering at the University of New South Wales 150 The Accuracy of Electrical Measurements made by Electronic Techniques J.M. Warner, B.Sc., Non-Member, Australian Post Office Research Laboratories, Melbourne 156 A Polar Co-ordinate Multiparameter Display J.A. Coekin, B.Sc., Ph.D., M.I.E.Aust, Senior Lecturer in Charge of Electrical Engineering, James Cook University of North Queensland 161 Low Cost Computer Compatible Data Logger A. Ceresa, M.I.E.(Aust), M.I.R.E.E.(Aust), Experimental Officer, Division of Irrigation Research, CS.I.R.O. 168 The Generation of Pseudo-Random Binary Sequences- for Testing Very Wide Band Systems J.A. Coekin and J.R. Wicking, Electrical Engineering Division, James Cook University of North Queensland . 173 Development in Microwave Instrumentation for Industrial Process Control D.W. Griffin, B.E., B.A., Ph.D., C.Eng., Reader in Electrical Engineering, University of Adelaide 180 Precise Function Generation under Digital Control Sl D.A. Pucknell, B.Sc., B.E., M.I.E.E., Senior Lecturer in Electrical Engineering, University of Adelaide, : c Adelaide, South Australia 186 New Solid State Microwave Generators for Industrial Applications c C.J. McRae, B.Tech., B.E., M.I.E.Aust. (Student); and D.W. Griffin, B.E., B.A., Ph.D., E.Eng. (Reader), : c Department of Electrical Engineering, The University of Adelaide 193 ; P Digital Diffusion Analogue „ M.N. Svilans, B.Sc., B.E.(Hons), University of Adelaide 201 Electronic Techniques in Telemetering Systems CR. Farrell, B.E., Electronics Engineer, M.W.S. & D.B., Sydney 206 The Detection and Location of a Noise Source in a Dispersive Medium G.J. Cybula, B.Sc., (Tech.) Grad. I.E. Aust, Electrical Engineer, Operations Division, Australian Atomic ; i Energy Commission; and T.J. Ledwidge, B.Sc., Ph.D., C.Eng., M.I.E.E., M.lnst P. Head Engineering Physics Section, Engineering Research Division, Australian Atomic Energy Commission 215 , The Acquisition of Wind Tunnel Data using a PDP15/20 Computer < RoyE. Kane, B.E..M.I.E. Aust 222 A Theoretical Study of the Effects of Dispersion on Cross-Correlograms ' G.J. Cybula, B.Sc.(Tech), Grad. I.E.Aust., Elect. Eng., Operations Div., A.A.E.C.; and ' R.W.Harris. B.Sc., M.Sc, Ph.D., A.M.I.R.E.E,(Aust), Research Scientist, Eng. Research Div., A.A.E.C. ... 229 AC-to-DC Conversion for Rapid Precise Digital Measurements E.L. Harris, B.Sc., M.Sc, M.I.R.E.E., Senior Lecturer in Electrica! Engineering, N.S.W. Institute of Technology 234 COMPUTER BASED TELEMETRY SYSTEMS FOR REMOTE MONITORING AND CONTROL R.A. Smythers, M.A., Senior Applications Engineer, Cutler-Hammer Australia Pty Limited SIMIABXt Major operating objective» for computer based reaote monitoring and control ayeteae are pre- sented from which emerge the prime requirements of flexibility and ease of expandability. A typical system configuration containing a number of alternatives is then examined with major features of the system receiving detailed attention. The major objective ot tbia examination is to consider soae of the alternatives, and their consequences, that become possible once a computer forms the heart of auch a system. This article is not con- cerned with basic technology involved but rather with system design concepts and philosophies that ensure com- patible and efficient utilisation of components through the system. Finally, consideration of possible future trends and developments endorse the primary requirements for flexibility and where the possibility of future needs are considered during the design of the initial system. XNTBODUCTION« For many decades conventional IMJDR OBJECTIVES FOR MONITORING AND CONTROL telemetry systems have been used to provide remote SYSTEUS: The following simnariae the major object- monitoring and control facilities of plant and dis- ives that must be satisfied by present day, large tribution networks. However, many of the industries scale remote supervisory systems. These objectives that employ such Systeme hare undergone significant are presented in two stages, firstly to provide - and radical changes during the last few years. This is particularly true of the public supply utilities, 1. Meaningful presentation of selected operating electricity, gas and water. These utilities have been data on a periodic aoä operator request basis. subjected to an ever increasing demand pattern along 2. Automatic presentation of alarm conditions, in a with increasingly more complex and stringent distrib- meaningful manner so as to bring the operator's ution problems. Associated with this change has been attention to areas of the system that need his an increasing awareness of the necessity to operate attention. with respect to tight economic objectives and con- straints. These requirements have generated the need 3. The ability to calculate and present to the for more powerful and flexible data gathering and operator derived parameters such as efficiency. data reduction facilities that provide vital assist- 4. Easy to use control facilities. Ideally the ance to the human operator in his system assessment security aspects of making control actions and control activity. To meet this need the variable should be looked after automatically. program computer has «merged as a potentially powerful and flexible tool. This subject is currently Attract- 5.