Continued from: Jobs I've Had - Telecom Australia (3) The diagram below, which I will go into more detail another day, is a very basic diagram of an ARE-11 exchange. The top part above the dashed line is the original crossbar exchange with relays and electro-mechanical switches, the bottom part is the processor control and interfacing electronics which, in the case of Inala, was brand new in 1985 when I started working there. The ARE-11 system as the whole exchange type was known was implemented in Australia from 1976. The bottom left corner of the diagram has a box marked 'SCS' which stands for Subscriber Category Store. This was an electronic data store which held information about every phone number in the exchange - if it was connected or disconnected, what type of dial tone was required, was the phone line allowed to make local calls and long distance calls, and so on. A very basic terminal (keyboard and screen) was connected to the Operations and Maintenance Processor (OMP) which is where we would type in commands to connect, disconnect or change the phone line characteristics - this was called the telephone numbers category. The command to display the subscribers category was DISC: 372 4586; and the result would be something like C5 40 C3 - a set of hexadecimal codes which meant the phone line was disconnected and could not be used for outgoing phone calls or receive incoming phone calls. To change the subscribers category the command was CHSC: 372 4586 C6 40 A5; - with that hexadecimal code meaning the phone line could make outgoing calls and receive incoming calls. Hexadecimal was to become a second language for me..!! The last part of the phone line connection process was to test the line, to make sure it had a dial tone, and that there were no faults in the cable heading out into the street. Staff from other sections dealt with the street cables and the actual phones in peoples houses and businesses - my work was strictly in the telephone exchange. So this was my first task for a while - connecting and disconnecting phone lines in the exchange, manually running the wires to connect the phone number to the cable pair on the MDF, writing out the record cards, reading the meter, and programming the category on the terminal connected to the ARE-11 exchange. The Senior Technical Officer at Inala was Jeff and the Technician was Merv - both very nice people to work with. With Andy and I both working at Inala we got through the work on connecting or disconnecting phone lines quite quickly, so it was not long before I was also taken to visit Wacol exchange where Jim was the Technician. It also became apparent that I was entitled to a driving allowance if I had to drive the company car during the day. It was not much in dollar terms but my day was soon arranged so that I had to drive to or from Inala, Wacol or Sherwood most days. The cars we had were Nissan Bluebird station wagons and there was a distant photo of one on the first blog page - Jobs I've Had - Telecom Australia (1). The big orange Telecom Australia stickers on the side of the car were quite obvious and the red letter Z number plates also quite distinctive. I don't know exactly when I started to learn more about the ARE-11 telephone exchanges but I suspect it was quite soon. There were special services in addition to the normal telephone lines at exchanges, and there were also rotary groups which was the term for a business which had one advertised phone number but several phone lines working directly off it. I was soon taught by the Technicians how to connect the rotary groups which entailed special wiring in the equipment room, and also how to connect special services for bank data lines or fire alarms. Special services often needed additional wiring either on the MDF or in the equipment room to connect amplifiers or splitter/combiners into the circuit.
After my six months of field experience had finished the next main phase of my apprenticeship was back at Chermside but there was also a trip to Sydney. To be continued.....
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AuthorI love to understand things, how they work, why they happen - I'm always learning and keen to investigate... Archives
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