System MCET-1 An Experimental Microprocessor-Controlled Electronic Telex

Abstract

System MCET-1, an experimental Microprocessor-Controlled Electronic Telex for 200 lines/trunks, has been described. Scanning, decadic out pulsing and character transfer are done by autonomous units. Character transfer takes place on a time-division basis through the ‘Character Transfer Highway’ connecting all terminations which are treated as memory- mapped input-output ports of microprocessor for transmission of signals. All operational programs, except ‘Scanner Program’, are executed in the base level. Scanner Program, called under interrupt from ‘Autonomous Scanning Unit’, allots a Call Control Register (CCR) for each new call and enters the scan data into relevant CCRs. Executive Control Program periodically monitors the status of CCRs and schedules the programs.

The system has greatly simplified operational software and can accommodate an elaborate maintenance and diagnostic software.

Indexing Terms:

• Electronic Telex
• Microprocessor-based Telex
• Switching Systems

Additional information

Notes on contributors

Avinash K. Shrivastava

SHRIVASTAVA, AVINASH KUMAR: To his credit is more than eleven years of experience in the field of electronic switching systems. While at TRC, New Delhi, he worked for development of the first Indian Stored Program Controlled (SPC) electronic phone exchange. In 1973, he was selected by ITI Bangalore, to organize the production of 1000-line SPC electronic telephone exchange for the first commercial field trial at New Delhi. He has received training in design, engineering and production of electronic switching system: Metaconta 10C at Bell Telephone Manufacturing Company, Belgium. R&D work on electronic telex was initiated by him in ITI during 1975. His accomplishments include work on improving the call handling capacity of SPC switching systems.

Authored several papers in Indian & foreign journals. Presently, working as Deputy Chief Engineer in Switching R&D Wing of ITI Ltd., Bangalore. He is the Group Leader for Electronic Telex and Microprocessor-Controlled Road Traffic Signalling Systems.

Mr. Shrivastava is a Senior Member of IEEE, a Member of Institution of Engineers (I), a Member of Institute of Standards Engineers, a Member of Computer Society of India and an Associate member of Institution of Electronics and Telecommunication Engineers.

Debasish Banerjee

BANERJEE, DEBASISH: (b. Oct. 1949; Calcutta). Obtained BSc Degree with Honours in Physics from Calcutta University in 1969. Passed BTech in Radio Physics and Electronics and MTech in Control Systems and Digital Techniques from Centre of Advanced Studies in Radio Physics and Electronics, Univ. of Calcutta in 1972 and 1974 respectively.

Joined Indian Telephone Industries Ltd., Bangalore as Asstt. Executive Engineer in 1974. Initially, worked for Stronger Circuit Development. Involved in Electronic Telex Development since 1975. Presently, working on Microprocessor-Based Telex.

S. D. Srinivasan

SRINIVASAN, S D: (b. Dec. 1951; (Electronics & Telecomm.) Degree from Madras University in 1974, securing sixth rank in the State of. S Tamil Nadu. Joined Indian Telephone Industries Ltd., Bangalore; in 1974 as Asstt. Executive Engineer in the Switching R&D Department. Completed work on development and production of Tele printer Interface for Commercial Trial Version of SPC Electronic Telephone Exchange. Involved in the development of electronic telex during 1975–1977. Presently, working in Abu Dhabi at the International Transit Switching Centre, Emirtel.