Serial loop data transmission system fault locator

Claim 2

A fault locator system for a serial loop data communications system having a plurality of serially connected terminals and a central control station connected to both ends of the serial line forming a loop and characterized by: fault detection and signalling means at each terminal and comprising; means for detecting an out of synchronous condition existing for a predetermined time and for indicating a fault condition upon the occurence of said condition; means responsive to the indication of a fault condition for transmitting on the loop a predetermined signal including a unique group of bits identifying the particular terminal location; and means responsive to incoming data for detecting nonfaulty signals from a previous terminal for interrupting the signal transmitting means.

Claim 3

A fault locator system as set forth in claim 1 in which the means for detecting an out of synchronous condition includes circuit means rendered active by a synchronous condition for a period substantially longer than required to transmit one cycle of a data channel whereby temporary losses of synchronization will not initiate a fault routine.

Claim 4

A fault locator system for a serial loop data communications system having a plurality of serially connected terminals and a central control station connected to both ends of the serial line, thus forming a loop characterized by: fault detection and signalling means at each terminal and comprising; means for detecting an out of synchronous condition existing for a predetermined time and for indicating a fault condition upon the occurrence of said condition; means for monitoring the received data for indicating a failure of received data; means responsive to the indication of a fault condition and the failure to receive data for transmitting on the loop, a first predetermined signal including a unique group of bits identifying the particular terminal location when both a fault condition and failure to receive data occur simultaneously and for transmitting a second signal including the same unique group of bits identifying the terminal when a fault condition only exists; and means responsive to incoming data for detecting nonfaulty signals from a previous terminal for interrupting the signal transmitting means.

Claim 5

A fault locator system for a serial loop data communications system having a plurality of serially connected terminals and a central control station connected to both ends of the serial line, thus forming a loop characterized by: fault detection and signalling means at each terminal and comprising; means for detecting an out of synchronous condition existing for a predetermined time and for indicating a fault condition upon the occurrence of said condition; means for monitoring the received data for indicating a failure of received data; means responsive to the indication of a fault condition and the failure to receive data for transmitting on the loop, a first predetermined signal including a unique group of bits identifying the particular terminal location when both a fault condition and failure to receive data occur simultaneously and for transmitting a second signal including the same unique group of bits identifying the terminal when a fault condition only exists; and means responsive to incoming data for detecting nonfaulty signals from a previous terminal for interrupting the signal transmitting means.

Claim 6

A fault locator system as set forth in claim 3 in which the means for detecting an out of synchronous condition includes circuit means rendered active by a synchronous condition for a period substantially longer than required to transmit one cycle of a data channel whereby temporary losses of synchronization will not initiate a fault routine.

Claim 7

A fault locator system as set forth in claim 4 in which the means for monitoring the received data for indicating a loss of data includes circuit means rendered active by the received data for a time period substantially longer than the data bit interval whereby a loss of signal indication will not be provided until the loss persists for a time period determined by the active period of the said circuit means.

Claim 8

A fault locator system for a serial loop data communications system having a plurality of serially connected terminals and a central control station connected to both ends of the serial line, thus forming a loop characterized by: fault detection and signalling means at each terminal and comprising; means for detecting several transmission fault conditions and providing an indication of each transmission fault detected; means responsive to the fault indications for transmitting on the loop predetermined signals indicating the nature of the fault, said signals including a unique group of bits identifying the particular terminal location; and means responsive to incoming data for detecting nonfaulty signals from a previous terminal for interrupting the signal transmitting means.

Claim 9

A fault locator system for a serial loop data communications system having a plurality of serially connected terminals and a central control station connected to both ends of the serial line, thus forming a loop characterized by: fault detection and signalling means at each terminal and comprising; means for detecting several transmission fault conditions and providing an indication of each transmission fault detected; means responsive to the fault indications for transmitting on the loop predetermined signals indicating the nature of the fault, said signals including a unique group of bits identifying the particular terminal location; and means responsive to incoming data for detecting nonfaulty signals from a previous terminal for interrupting the signal transmitting means.