System and method for startup of a detector loop

1. A hazard detector electrically connected to a circuit,

wherein the circuit includes:

a plurality of circuit ends including a first end and a second end, and a plurality of detectors including the detector, wherein the detector is connected intermediate the plurality of circuit ends,

a circuit driver connected to the plurality of circuit ends so that the circuit forms a loop circuit, the circuit driver including a first controller controlling one or more power sources to selectively provide power to the first end and the second end, and

the detector comprising

a second controller and a switch which is a short isolator switch that, when opened, breaks electrical continuity downstream of the detector, wherein the detector scans for a short at startup by

receiving power,

closing the switch,

measuring one or more circuit parameters, and

determining whether there is a short based on the one or more circuit parameters,

when there is a short, the detector transmits a first circuit communication that identifies the short;

wherein the detector when powered provides status by:

receiving a second circuit communication requesting an amount of elapsed time since receiving power and a unique detector identifier, and

transmitting a third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier.

2. A circuit comprising:

the plurality of circuit ends including the first end and the second end, and a plurality of detectors including the detector of claim 1 , connected intermediate the plurality of circuit ends,

the circuit driver connected to the plurality of circuit ends so that the circuit forms the loop circuit, the circuit driver including the first controller controlling one or more power sources to selectively provide power to the first end and the second end, and

wherein the circuit driver scans circuit continuity during startup by:

transmitting power to the first end,

monitoring the second end, and

when the circuit driver senses power at the second end, the circuit driver determines continuity exists.

3. The circuit of claim 2 , wherein when the circuit driver determines continuity exists, the circuit driver maps circuit topology by:

transmitting the second circuit communication from the first end, requesting from the plurality of detectors the amount of elapsed time since receiving power and the unique detector identifier for the detector,

receiving, from each of the plurality of detectors, the third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier, and

mapping circuit topology based the unique detector identifier and the amount of elapsed time since receiving power.

4. The circuit of claim 2 , wherein the circuit driver detects circuit discontinuity at startup by

receiving the first circuit communication at the first end from the detector, thereby determining there is a circuit short, and

failing to receive a circuit communication or sense power at the second end within a predetermined period of time, thereby determining there is a circuit break.

5. The circuit of claim 2 , wherein when there is a circuit discontinuity, the circuit driver maps a first segment topology of the circuit from the first end to the circuit discontinuity by

transmitting the second circuit communication, requesting the amount of elapsed time since receiving power and the unique detector identifier,

receiving the third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier and

mapping the first segment topology of the circuit between the first end and the circuit discontinuity based the unique detector identifier and the amount of elapsed time since receiving power from the first end.

6. The circuit of claim 4 , wherein when there is the circuit discontinuity, the circuit driver maps a second segment topology of the circuit from the second end to the circuit discontinuity by

transmitting power to the second end,

detecting the circuit discontinuity through the second end by

receiving the first circuit communication at the second end from a second detector, thereby confirming there is the circuit short, or failing to receive the circuit communication within the predetermined period of time, thereby confirming there is the circuit break,

transmitting the second circuit communication, requesting the amount of elapsed time since receiving power and the unique detector identifier,

receiving the third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier, and

mapping the second segment topology of the circuit between the second end and the circuit discontinuity based the unique detector identifier and the amount of elapsed time since receiving power from the second end.

7. The circuit of claim 4 , wherein the circuit driver determines a location of the circuit discontinuity combining the mapped first segment topology and mapped second segment topology of the circuit.

8. The circuit of claim 2 , wherein the detector acknowledges receiving power at startup by issuing an acknowledgment pulse to the circuit.

9. The circuit of claim 4 , wherein the detector scans for the circuit break at startup by failing to receive an acknowledgement pulse within the predetermined period of time.

10. A method of scanning for a short at startup by a hazard detector electrically connected to a circuit,

wherein the circuit includes:

a plurality of circuit ends including a first end and a second end, and a plurality of detectors including the detector, wherein the detector is connected intermediate the plurality of circuit ends,

a circuit driver connected to the plurality of circuit ends so that the circuit forms a loop circuit, the circuit driver including a first controller controlling one or more power sources to selectively provide power to the first end and the second end, and

the detector comprising

a second controller and a switch which is a short isolator switch that, when opened, breaks electrical continuity downstream of the detector,

wherein the method comprises

receiving power,

closing the switch,

measuring one or more circuit parameters, and

determining whether there is a short based on the one or more circuit parameters,

when there is a short, the detector transmits a first circuit communication that identifies the short,

wherein the detector when powered provides status by:

receiving a second circuit communication requesting an amount of elapsed time since receiving power and a unique detector identifier, and

transmitting a third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier.

11. A method of scanning circuit continuity at startup by the circuit driver electrically connected to a circuit,

wherein the circuit includes:

the plurality of circuit ends including the first end and the second end, and a plurality of detectors including the detector of claim 10 , connected intermediate the plurality of circuit ends,

the circuit driver connected to the plurality of circuit ends so that the circuit forms the loop circuit, the circuit driver including the first controller controlling one or more power sources to selectively provide power to the first end and the second end, and

wherein the method comprises

transmitting power to the first end,

monitoring the second end, and

when the circuit driver senses power at the second end, the circuit driver determines continuity exists.

12. The method of claim 11 , wherein when the circuit driver determines continuity exists, the circuit driver maps circuit topology by:

transmitting the second circuit communication from the first end, requesting from the plurality of detectors the amount of elapsed time since receiving power and the unique detector identifier for the detector,

receiving, from each of the plurality of detectors, the third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier, and

mapping circuit topology based the unique detector identifier and the amount of elapsed time since receiving power.

13. The method of claim 11 , wherein the circuit driver detects circuit discontinuity at startup by

receiving the first circuit communication at the first end from the detector, thereby determining there is a circuit short, and

failing to receive a circuit communication or sense power at the second end within a predetermined period of time, thereby determining there is a circuit break.

14. The method of claim 11 , wherein when there is a circuit discontinuity, the circuit driver maps a first segment topology of the circuit from the first end to the circuit discontinuity by

transmitting the second circuit communication, requesting the amount of elapsed time since receiving power and the unique detector identifier,

receiving the third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier and

mapping the first segment topology of the circuit between the first end and the circuit discontinuity based the unique detector identifier and the amount of elapsed time since receiving power from the first end.

15. The method of claim 13 , wherein when there is the circuit discontinuity, the circuit driver maps a second segment topology of the circuit from the second end to the circuit discontinuity by

transmitting power to the second end,

detecting the circuit discontinuity through the second end by

receiving the first circuit communication at the second end from a second detector, thereby confirming there is the circuit short, or failing to receive the circuit communication within the predetermined period of time, thereby confirming there is the circuit break,

transmitting the second circuit communication, requesting the amount of elapsed time since receiving power and the unique detector identifier,

receiving the third circuit communication responsive to the second circuit communication, including the amount of elapsed time and the unique detector identifier, and

mapping the second segment topology of the circuit between the second end and the circuit discontinuity based the unique detector identifier and the amount of elapsed time since receiving power from the second end.

16. The method of claim 13 , wherein the circuit driver determines a location of the circuit discontinuity combining the mapped first segment topology and mapped second segment topology of the circuit.

17. The method of claim 11 , wherein the detector acknowledges receiving power at startup by issuing an acknowledgment pulse to the circuit.

18. The method of claim 13 , wherein the detector scans for the circuit break at startup by failing to receive an acknowledgement pulse within the predetermined period of time.