Diagnostic method and apparatus for detecting and locating computer network discontinuities

A method of detecting discontinuities in a computer network system, the method comprising the steps of:

• connecting a first transmitter, a first receiver, a second transmitter, and a second receiver operatively to a server;
• connecting a plurality of workstations serially in a daisy-chain configuration by a transmit path;
• connecting the first transmitter and the second transmitter operatively to the transmit path;
• connecting the plurality of workstations serially in a daisy-chain configuration by a receive path;
• connecting the first receiver and the second receiver operatively to the receive path;
• enabling the first transmitter and the first receiver during a first phase of a breakage diagnostic mode;
• disabling the second transmitter and the second receiver during the first phase of the breakage diagnostic mode;
• transmitting a first test sequence by the first transmitter;
• transmitting a first acknowledgement sequence in response to at least one of the plurality of workstations receiving the first test sequence;
• receiving a quantity of first acknowledgement sequences by the first receiver;
• disabling the first transmitter and the first receiver during a second phase of the breakage diagnostic mode;
• enabling the second transmitter and the second receiver during the second phase of the breakage diagnostic mode;
• transmitting a second test sequence by the second transmitter;
• transmitting second acknowledgement sequence in response to at least one of the plurality of workstations receiving the second test sequence;
• receiving a quantity of second acknowledgement sequences by the second receiver;
• comparing the quantity of first acknowledgement sequences with the quantity of second acknowledgement sequences;
• detecting a discontinuity in the computer network in response to an outcome of the comparison of the quantity of first acknowledgement sequences with the quantity of second acknowledgement sequences, the transmit path including a first end and a second end, the receive path including a first end and second end;
• connecting the first transmitter between the first end of the transmit path and the server;
• connecting the second transmitter between the second end of the transmit path and the server;
• connecting the first receiver between the first end of the receive path and the server;
• connecting the second receiver between the second end of the receive path and the server, the receive path being separate from the transmit path;
• enabling the first transmitter and the first receiver during a normal mode;
• disabling the second transmitter and the second receiver during the normal mode;
• and
• accessing at least one of the plurality of workstations with the first transmitter and the first receiver during the normal mode.

A computer network control unit, the computer network control unit comprising:

• a first transmitter;
• a first receiver;
• a second transmitter;
• and
• a second receiver, the first transmitter, first receiver, second transmitter, and second receiver adapted for being operatively connected to a server and a plurality of workstations serially connected in a daisy-chain configuration by a transmit path and a receive path, the first transmitter being operatively connected to the transmit path, the second transmitter being operatively connected to the transmit path, the first receiver being operatively connected to the receive path, the second receiver being operatively connected to the receive path, the transmit path including a first end and a second end, the first transmitter being connected between the first end of the transmit path and the server, the second transmitter being connected between the second end of the transmit path and the server, the receive path including a first end and a second end, the first receiver being connected between the first end of the receive path and the server, the second receiver being operatively connected between the second end of the receive path and the server, the receive path being separate from the transmit path, the first transmitter and the first receiver being enabled during a normal mode, the second transmitter and the second receiver being disabled during the normal mode, the first transmitter and the first receiver being used to access at least one of the plurality of workstations during the normal mode, the first transmitter and the first receiver being enabled during a first phase of a breakage diagnostic mode, the second transmitter and the second receiver being disabled during the first phase of the breakage diagnostic mode, the first transmitter transmitting a first test sequence, the first receiver receiving a quantity of first acknowledgement sequences transmitted by at least one of the plurality of workstations in response to receiving the first test sequence, the first transmitter and the first receiver being disabled during a second phase of the breakage diagnostic mode, the second transmitter and the second receiver being enabled during the second phase of the breakage diagnostic mode, the second transmitter transmitting a second test sequence, the second receiver receiving a quantity of second acknowledgement sequences transmitted by at least one of the plurality of workstations in response to receiving the second test sequence, the quantity of first acknowledgement sequences being compared with the quantity of second acknowledgement sequences to determine whether a discontinuity in a computer network has occurred.