Browse Prior Art Database

Telephone Answering System

IP.com Disclosure Number: IPCOM000081770D
Original Publication Date: 1974-Aug-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 3 page(s) / 49K

Publishing Venue

IBM

Related People

Kolpek, RA: AUTHOR

Abstract

Calls to any of a number of telephones 9 can be answered at message center 10, by providing each telephone 9 with an I/O unit 16 that cooperates with a central controller 15 on a time multiplex basis. Each I/O unit 16 is sequentially addressed and processed through four sequential control phases A, B, C, and D by clock 12.

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Telephone Answering System

Calls to any of a number of telephones 9 can be answered at message center 10, by providing each telephone 9 with an I/O unit 16 that cooperates with a central controller 15 on a time multiplex basis. Each I/O unit 16 is sequentially addressed and processed through four sequential control phases A, B, C, and D by clock 12.

An incoming call is detected by the associated I/O unit 16 and ring latch 17 is set. When clock 12 addresses the I/O unit 16, the ring status of latch 17 is transmitted to timer 14 over indicator line 18 during phase A. The address of the I/O unit 16 is read from clock lines 13 and is stored in one of several registers 19 in association with a running timer. During phase C, the ring latch 17 is reset.

If telephone 9 remains unanswered, the time accumulated in register 19 will exceed a set threshold and when the I/O unit 16 is again addressed, timer 14 will put a signal on ready line 20. This ready signal is received by controller 15, which places the address of the "ready" I/O unit 16 in its current address register
29. This address operates through a switch matrix 22 to cut the operator in on the line 11 to the ringing telephone 9. It also lights a lamp 21 in a display matrix to show a name that identifies the ringing phone. Controller 15 also puts a signal on control line 25 at Phase D to set control latch 28.

The operator answers the intercepted call by depressing answer key 23 and can take a message, if desired. Depressing "Message waiting key" 24 causes controller 15 to put a signal on control line 25 during phase B, when the address on lines 13 matches the address in current address register 29. This signal sets latch 26 of the addressed unit 16 to flash lamp 27.

Had a second call on a different line, produced a signal on ready line 20 while the operator was occupied with answering the first call, controller 15 would operate to set the control latch 28 of the associated I/O unit 16 as described above. When the combined ring and control status latches were detected subsequently upon addressing by the controller 15, the call waiting lamp 33 would be lighted to indicate to the operator that an additional call was waiting. The operator can then elect to leave the call waiting w...