Redundant data transmission system

Claim 2

A message metering system, for metering the usage of a plurality of subscribers in a telephone system where each subscriber is associated with a multi-state signal, comprising, means responsive to the addressing of each subscriber for sensing the associated multi-state subscriber signal, memory means having memory locations corresponding to each subscriber, said memory means concurrently addressed during the addressing of each corresponding subscriber for storing usage information derived from said multi-state signal in a memory location associated with the addressed subscriber, first and second storage units connected to said memory means over redundant first and second data paths, respectively, where only one of said storage units and the connected data path is active while the other of said storage units and the connected data path is inactive, and first and second control network means for enabling one at a time said first and second redundant data paths, respectively.

Claim 3

A message metering system, for metering the usage of a plurality of subscribers in a telephone system where each subscriber is associated with a multi-state signal, comprising, means responsive to the addressing of each subscriber for sensing the associated multi-state subscriber signal, memory means having memory locations corresponding to each subscriber, said memory means concurrently addressed during the addressing of each corresponding subscriber for storing usage information derived from said multi-state signal in a memory location associated with the addressed subscriber, first and second storage units connected to said memory means over redundant first and second data paths, respectively, where only one of said storage units and the connected data path is active while the other of said storage units and the connected data path is inactive, and first and second control network means for enabling one at a time said first and second redundant data paths, respectively.

Claim 4

A message metering system, for metering the usage of a plurality of subscribers in a telephone system where each subscriber is associated with a multi-state signal, comprising, means responsive to the addressing of each subscriber for sensing the associated multi-state subscriber signal, memory means having memory locations corresponding to each subscriber, said memory means concurrently addressed during the addressing of each corresponding subscriber for storing usage information derived from said multi-state signal in a memory location associated with the addressed subscriber, first and second storage units connected to said memory means over redundant first and second data paths, respectively, where only one of said storage units and the connected data path is active while the other of said storage units and the connected data path is inactive, and first and second control network means for enabling one at a time said first and second redundant data paths, respectively.

Claim 5

The message metering system of claim 1 wherein said first and second control network means are responsive to first and second alarm signals, respectively, associated with said first and second data paths, respectively, and wherein said first and second control network means are each operative to force inactive an active one of said first and second data paths, respectively, in response to said first and second signals, respectively.

Claim 6

The message metering system of claim 2 wherein each of said first and second alarm signals is produced in response to alarms of different priorities, said system further including means for enabling one of said data paths active in response to an alarm associated with the other of said data paths provided that said other of said data paths does not have an alarm of a higher priority.

Claim 7

In a message metering apparatus for metering subscriber usage of a telephone system including a first data path for transmitting information to a first output device, including first alarm means for producing a first alarm signal in response to an alarm condition associated with said first data path and said first output device; and including a redundant second data path for transmitting information to a second output device, including second alarm means for producing a second alarm signal in response to an alarm condition associated with said second data path and said second output device; the redundancy control apparatus comprising, first control network means, connected to receive said first and said second alarm signals, and including a first enabling means for producing a first enable signal for rendering saId first data path active, second control network means, connected to receive said first and said second alarm signals, including second enabling means for producing a second enable signal for rendering said second data path active, means connecting said second enable signal as an input to said first enabling means whereby said second enable signal enables said first enabling means to render said first data path active in response to said second alarm signal in the absence of said first alarm signal, means for connecting said first enable signal as an input to said second enabling means whereby said first enable signal enables said second enabling means to render said second data path active in response to said first alarm signal in the absence of said second alarm signal.

Claim 8

In a message metering apparatus for metering subscriber usage of a telephone system including a first data path for transmitting information to a first output device, including first alarm means for producing a first alarm signal in response to an alarm condition associated with said first data path and said first output device; and including a redundant second data path for transmitting information to a second output device, including second alarm means for producing a second alarm signal in response to an alarm condition associated with said second data path and said second output device; the redundancy control apparatus comprising, first control network means, connected to receive said first and said second alarm signals, and including a first enabling means for producing a first enable signal for rendering saId first data path active, second control network means, connected to receive said first and said second alarm signals, including second enabling means for producing a second enable signal for rendering said second data path active, means connecting said second enable signal as an input to said first enabling means whereby said second enable signal enables said first enabling means to render said first data path active in response to said second alarm signal in the absence of said first alarm signal, means for connecting said first enable signal as an input to said second enabling means whereby said first enable signal enables said second enabling means to render said second data path active in response to said first alarm signal in the absence of said second alarm signal.

Claim 9

A message metering system for metering the usage of a plurality of subscribers in a telephone system where each subscriber is associated with a multi-state signal, comprising, means responsive to the addressing of each subscriber for sensing the associated multi-state subscriber signal, memory means having memory locations corresponding to each subscriber, said memory means uniquely addressed during the addressing of corresponding subscribers for storing usage information derived from said multi-state signal in a memory location associated with the addressed subscriber, a plurality of storage units, a plurality of independent and redundant data paths each connecting said memory means to a different one of said storage units wherein each data path is activated by a different enable signal, alarm means for generating alarm signals for indicating alarm conditions associated with said storage units and connected data paths, a plurality of control networks, each one associated with a different data path for controlling the state of the associated data path with an enable signal, each of said control networks including enabling means responsive to one or more alarm signals for forcing the data path associated with said one or more alarm signals inactive.

Claim 10

A message metering system for metering the usage of a plurality of subscribers in a telephone system where each subscriber is associated with a multi-state signal, comprising, means responsive to the addressing of each subscriber for sensing the associated multi-state subscriber signal, memory means having memory locations corresponding to each subscriber, said memory means uniquely addressed during the addressing of corresponding subscribers for storing usage information derived from said multi-state signal in a memory location associated with the addressed subscriber, a plurality of storage units, a plurality of independent and redundant data paths each connecting said memory means to a different one of said storage units wherein each data path is activated by a different enable signal, alarm means for generating alarm signals for indicating alarm conditions associated with said storage units and connected data paths, a plurality of control networks, each one associated with a different data path for controlling the state of the associated data path with an enable signal, each of said control networks including enabling means responsive to one or more alarm signals for forcing the data path associated with said one or more alarm signals inactive.

Claim 11

The apparatus of claim 4 wherein not more than one data path is active at a time.

Claim 12

The apparatus of claim 4 further including means for inhibiting said enabling means from forcing the associated data path inactive until after a control signal is received.

Claim 13

The apparatus of claim 4 wherein each of said enabling means further includes means for enabling the associated data path active in response to an inactive state of an enabling signal from another enabling means.

Claim 14

The apparatus of claim 8 wherein said alarm means includes means for simulating an alarm to force said data paths into predetermined activity states.

Claim 15

The apparatus of claim 8 wherein each of said enabling means includes means responsive to an alarm signal in the associated data path for inhibiting the enabling of the associated data path in response to an inactive state of an enabling signal from another enabling means.

Claim 16

The apparatus of claim 10 including means for generating a plurality of alarm signals of different priority classes and wherein each of said enabling means includes means responsive to an alarm signal in the associated data path for inhibiting the enabling of said associated data path in response to an inactive state of an enabling signal from another enabling means.

Claim 17

The apparatus of claim 4 wherein said alarm means includes means for generating alarm signals of different priority classes and wherein each of said enabling means is responsive to an alarm signal for forcing the associated data path inactive provided no other enabling means receives a higher priority alarm.

Claim 18

The apparatus of claim 12 wherein said alarm signals have two priority classes.