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Browse Prior Art Database

Reset and Seize Circuit

IP.com Disclosure Number: IPCOM000079582D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Brady, RL: AUTHOR

Abstract

This circuit reduces the complexity and cost of wiring to block access to switching matrix circuits, if a monitoring data processing equipment becomes inoperative. The circuit is particularly useful where a computer is used to provide toll ticketing or automatic message accounting, which affects the operation of telephone switching matrices in an office. The circuit stops any calls in progress when a system becomes inoperative, disconnects all calls and then causes backup equipment or operators to be switched. In-progress calls are disconnected to prevent a hang condition which, in turn, prevents use of backup equipment or reception of calls.

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Reset and Seize Circuit

This circuit reduces the complexity and cost of wiring to block access to switching matrix circuits, if a monitoring data processing equipment becomes inoperative. The circuit is particularly useful where a computer is used to provide toll ticketing or automatic message accounting, which affects the operation of telephone switching matrices in an office. The circuit stops any calls in progress when a system becomes inoperative, disconnects all calls and then causes backup equipment or operators to be switched. In-progress calls are disconnected to prevent a hang condition which, in turn, prevents use of backup equipment or reception of calls.

The circuit uses existing control circuits consisting of bistable relays to be reset to open and then set to busy, before assuming a stable-wait state. If the controlling system reestablishes control, the reset circuit is itself reset whether in mid-cycle or at the completion of a cycle and in a stable-wait state.

The circuit is shown using four form C contact relays W, X, Y and Z.

Relay W is supplied with minus 48 volts from input 10 and returns a ground signal via contact W1 to the controlling computer at terminals 15, and returns -48V from 10A via contact W2 and output 16. W is picked and held by a series of pulses or a steady-state signal from the processor into terminal 10. Switch 11 provides a manual reset.

If the controlling computer ceases operation, W is dropped and W1 grounds one side of X, Y and Z. W2 supplies a pick from 10A to relay X through Z1. Relay X is a...