Arrangement for removal of fault conditions in direct coupled information transfer systems

Claim 2

In an information transfer system which includes a pair of signal buses, each including at least one conductor, and a plurality of information transfer units connected in parallel paths between said buses each of said information transfer units having a first operating mode providing a first impedance between said buses, at least one additional operating mode providing an impedance between said buses less than said first impedance, add a failure mode maintaining an impedance between said buses less than said first impedance, an information protection arrangement comprising a circuit breaking device connected in each of said parallel paths in series with a respective one of said information transfer units, each of said circuit breaking devices operating to become nonconductive when the operating current through it exceeds a predetermined threshold, control means generating control signals to which all of said information transfer units not in said failure mode respond by switching to or continuing to operate in said first operating mode, and switching means to apply a voltage between said buses of a magnitude sufficient to operate any of said circuit breaking devices in series with an information transfer unit in said failure mode but insufficient to operate the ones of said circuit breaking devices in series with information transfer units in said first operating mode, said switching means being operative to apply said voltage only upon receipt of said control signal.

Claim 3

A system in accordance with claim 1 wherein said switching means includes means responsive to said control signals to generate fault signals if any of said information transfer units are in said failure mode and means responsive to said fault signals to apply said voltage between said buses.

Claim 4

In an information transfer system which includes a signal bus comprising a first plurality of conductors, a common return ground conductor, and a plurality of information transfer units, each of said information transfer units comprising at least one gating device connected between a corresponding bus conductor and said common return ground conductor, each of said gating devices having a first operating mode providing a first impedance between said corresponding bus conductor and said common return ground, at least one additional operating mode providing an impedance between said corresponding bus conductor and said common return ground less than said first impedance, and a failure mode maintaining an impedance between said corresponding bus conductor and said common return ground less than said first impedance, an information protection arrangement comprising a circuit breaking device serially connected with each of said gating devices, each of said circuit breaking devices operating to become nonconductive when current therethrough exceeds a predetermined threshold, control means for generating control signals to whiCh all of said gating devices not in said failure mode respond by switching to or continuing to operate in said first operating mode, and switching means to apply a voltage between said bus conductors and said common return ground of a magnitude sufficient to operate any of said circuit breaking devices in series with gating devices in said failure mode but insufficient to operate the ones of said circuit breaking devices in series with gating devices in said first operating mode, said switching means being operative to apply said voltage only upon receipt of one of said control signals.

Claim 5

In an information transfer system which includes a signal bus comprising a first plurality of conductors, a common return ground conductor, and a plurality of information transfer units, each of said information transfer units comprising at least one gating device connected between a corresponding bus conductor and said common return ground conductor, each of said gating devices having a first operating mode providing a first impedance between said corresponding bus conductor and said common return ground, at least one additional operating mode providing an impedance between said corresponding bus conductor and said common return ground less than said first impedance, and a failure mode maintaining an impedance between said corresponding bus conductor and said common return ground less than said first impedance, an information protection arrangement comprising a circuit breaking device serially connected with each of said gating devices, each of said circuit breaking devices operating to become nonconductive when current therethrough exceeds a predetermined threshold, control means for generating control signals to whiCh all of said gating devices not in said failure mode respond by switching to or continuing to operate in said first operating mode, and switching means to apply a voltage between said bus conductors and said common return ground of a magnitude sufficient to operate any of said circuit breaking devices in series with gating devices in said failure mode but insufficient to operate the ones of said circuit breaking devices in series with gating devices in said first operating mode, said switching means being operative to apply said voltage only upon receipt of one of said control signals.

Claim 6

A system in accordance with claim 3 wherein said switching means comprises means responsive to said control signals to generate fault signals if any of said gating devices are in said failure mode and means responsive to said fault signals to apply said voltage.

Claim 7

A system in accordance with claim 4 wherein said means responsive to said fault signals comprises means connected to said bus conductors to generate selection signals indicating which ones of said bus conductors are connected to gating devices in said failure mode and means responsive to said selection signals to apply said voltage only to those bus conductors connected to a gating device in said failure mode.

Claim 8

In an information transfer system which includes a signal bus comprising a first plurality of conductors, a common return ground conductor, and a plurality of information transfer units, each of said information transfer units comprising at least one gating device connected between a corresponding bus conductor and said common return ground conductor, each of said gating devices having a first operating mode providing a first impedance between said corresponding bus conductor and said common return ground, at least one additional operating mode providing an impedance between said corresponding bus conductor and said common return ground less than said first impedance, and a failure mode maintaining an impedance between said corresponding bus conductor and said common return ground less than said first impedance, an information protection arrangement comprising a circuit breaking device serially connected with each of said gating devices, each of said circuit breaking devices operating to become nonconductive when the current therethrough exceeds a predetermined threshold, control means for generating control signals to selectively activate and deactivate said information transfer units, the gating devices of said deactivated information transfer units not in said failure mode respond by switching to or continuing to operate in said first operating mode, said control means further generating a first signal indicating all information transfer units as being deactivated, means for generating a second signal if any of said gating devices are not in said first operating mode, means responsive to the concurrence of said first and said second signal to generate a first and second pulse, means responsive to said first pulse to store the present state of each of said bus conductors and generate a fault signal corresponding to the ones of said bus conductors having a gating device not in said first operating mode connected thereto, and means responsive to the concurrence of said second pulse and said fault signals to apply a voltage to those bus conductors having a gating device not in said first operating mode, said voltage being of sufficient magnitude to operate any of said circuit breaking devices in series with a gating device in said failure mode but insufficient to operate the ones of said circuit breaking devices in series with gating devices in said first operating mode.

Claim 9

In an information transfer system which includes a signal bus comprising a first plurality of conductors, a common return ground conductor, and a plurality of information transfer units, each of said information transfer units comprising at least one gating device connected between a corresponding bus conductor and said common return ground conductor, each of said gating devices having a first operating mode providing a first impedance between said corresponding bus conductor and said common return ground, at least one additional operating mode providing an impedance between said corresponding bus conductor and said common return ground less than said first impedance, and a failure mode maintaining an impedance between said corresponding bus conductor and said common return ground less than said first impedance, an information protection arrangement comprising a circuit breaking device serially connected with each of said gating devices, each of said circuit breaking devices operating to become nonconductive when the current therethrough exceeds a predetermined threshold, control means for generating control signals to selectively activate and deactivate said information transfer units, the gating devices of said deactivated information transfer units not in said failure mode respond by switching to or continuing to operate in said first operating mode, said control means further generating a first signal indicating all information transfer units as being deactivated, means for generating a second signal if any of said gating devices are not in said first operating mode, means responsive to the concurrence of said first and said second signal to generate a first and second pulse, means responsive to said first pulse to store the present state of each of said bus conductors and generate a fault signal corresponding to the ones of said bus conductors having a gating device not in said first operating mode connected thereto, and means responsive to the concurrence of said second pulse and said fault signals to apply a voltage to those bus conductors having a gating device not in said first operating mode, said voltage being of sufficient magnitude to operate any of said circuit breaking devices in series with a gating device in said failure mode but insufficient to operate the ones of said circuit breaking devices in series with gating devices in said first operating mode.