Method and apparatus for calculating voltage drop

1. A method for performing voltage drop calculations in an alarm circuit, comprising:

creating a circuit to be controlled;

displaying, on a graphical user interface, a graphical circuit layout based on the circuit created;

selecting, through the graphical user interface, a first device from a list of devices to add to the circuit;

calculating an estimated power supplied to the first device using modified nodal analysis of the circuit; and

determining whether the estimated power supplied to the first device is sufficient power for the first device to operate.

2. The method of claim 1 , further comprising:

selecting a second device from the list of devices to add to the circuit; and

verifying that the second device is on a list of compatible devices associated with the first device.

3. The method of claim 1 , further comprising:

identifying a device load limit of a controller used to control the circuit, the device load limit comprising at least one of a maximum number of addresses and a maximum number of device loads; and

determining whether the circuit comprises a device load within the device load limit.

4. The method of claim 1 , further comprising selecting second and third devices from the list of devices to add to the circuit in a T-Tapped configuration, the calculating step further comprising calculating estimated second and third power supplies to the second and third devices and recalculating the estimated power supplied to the first device.

5. The method of claim 1 , further comprising displaying the circuit on a monitor and indicating a pass or fall condition for the first device, the pass condition indicating that the estimated power supplied to the first device is sufficient for the first device to operate, the fail condition indicating that the estimated power supplied to the first device is not sufficient for the first device to operate.

6. A method for performing voltage drop calculations in an alarm circuit, comprising:

creating a circuit to be controlled;

selecting a first device from a list of devices to add to the circuit;

calculating an estimated power supplied to the first device using modified nodal analysis of the circuit; and

determining whether the estimated power supplied to the first device is sufficient power for the first device to operate, further comprising selecting a second device from the list of devices to add to the circuit, the calculating step further comprising calculating a second estimated power supplied to the second device and recalculating the estimated power supplied to the first device.

7. A method for performing voltage drop calculations in an alarm circuit, comprising:

creating a circuit to be controlled;

selecting a first device from a list of devices to add to the circuit;

calculating an estimated power supplied to the first device using modified nodal analysis of the circuit; and

determining whether the estimated power supplied to the first device is sufficient power for the first device to operate, the calculating step further comprising calculating a voltage level of the first device, the determining step further comprising comparing the voltage level to a low voltage limit defining a minimum operating voltage of the first device to determine whether the voltage level is within allowable limits.

8. A graphical interface tool for calculating voltage drop in a circuit, comprising:

a display displaying a graphical user interface (GUI) allowing a user to create a circuit layout representing a circuit to be controlled;

the GUI permitting. the user to select a controller to add to the circuit layout the controller being used to control the circuit, the controller receiving power from a power source, the controller having a worst-case voltage based on the power source;

the GUI permitting the user to select a first device from a list of devices displayed on the display to add to the circuit layout; and

a processor calculating a first voltage of the first device based on the worst-case voltage of the controller.

9. The tool of claim 8 , the processor using modified nodal analysis to calculate the first voltage of the first device.

10. The tool of claim 8 , the display displaying the circuit layout as a graphical circuit layout.

11. The tool of claim 8 , the display displaying the circuit layout in a table format.

12. The tool of claim 8 , the processor determining whether the first voltage of the first device is sufficient for the first device to operate and the display displaying a pass or fail condition based on the determining operation.

13. The tool of claim 8 , wherein the GUI permits the user to enter at least one voltage level provided by the power supply.

14. The tool of claim 8 , wherein the GUI permits the user to enter individual wire lengths associated with each device in the circuit layout created.

15. The tool of claim 8 , wherein the GUI provides real-time feedback regarding voltage drops for at least one device as the circuit layout is created and revised.

16. A computer readable medium or media comprising computer readable program instructions, which when executed by a computer system causes the computer system to calculate, a power supply of each device within a circuits comprising:

instructions for implementing a graphical user interface (GUI) allowing a user to create a circuit layout representing a circuit to be controlled;

instructions for controlling the GUI to permit the user to select a first device from a list of devices to add to the: circuit layout;

instructions for calculating an estimated power supplied to the first device using modified nodal analysis of the circuit; and

instructions for determining whether the estimated power supplied to the first device is sufficient power for the first device to operate.

17. The computer readable medium of claim 16 , the circuit further comprising nodes interconnected with one another, the program instructions further comprising instructions to define the nodes in the circuit.

18. The computer readable medium of claim 16 , the program instructions further comprising instructions for defining a list of compatible devices attachable to the circuit.

19. The computer readable medium of claim 16 , the program instructions further comprising instructions to define nodes within the circuit and means for defining a subsequent node based on a previous node.

20. The computer readable medium of claim 16 , further comprising means for displaying a failure status on a monitor when the first device is receiving insufficient power for operation.

21. The computer readable medium of claim 16 , the circuit further comprising interconnected nodes, each of the nodes representing a device, the program instructions further comprising instructions directing the computer system to automatically recalculate the power supplied to the devices when the circuit is revised.