US 2002/0118023 A1 · DETECTION OF DEVICES ON A LOCAL AREA NETWORK

Abstract

Determining that a slope of test values resulting from two test conditions being applied to a remote device via a network connection and a reference circuit is within a predetermined range, and applying full power to the remote device if the slope is within the predetermined range. The determination using the slope reduces the effects of voltage drop variation caused by diodes and leakage of current by transistors in the remote device. The determination is performed by first applying a first reference voltage to both the remote device and reference circuit and storing the resulting two voltages. Next, a second reference voltage is applied to both the remote device and reference circuit and the resulting two voltages are stored. A first difference is calculated from the two voltages resulting from the testing of the remote device, and a second difference is calculated from the two voltages resulting from the testing of the reference circuit. The absolute difference between the first and second differences is calculated. Finally, the absolute difference is compared with the predetermined range.

Claims12

Dependent claims

A method for supplying power to a remote device via a network connection, comprising the steps of

applying a first test condition via the network connection to the remote device;
measuring a first test result from the application of the first test condition to the remote device;
applying the first test condition to a reference circuit;
measuring a second test result from the application of the first test condition to the reference circuit;
applying a second test condition via the network connection to the remote device;
measuring a third test result from the application of the second test condition to the remote device;
applying the second test condition to the reference circuit;
measuring a fourth test result from the application of the second test condition to the reference circuit;
calculating a first difference between the first test result and the third test result;
calculating a second difference between the second test result and the fourth test result;
calculating a third difference between the second difference and the first difference;
comparing the third difference with a predefined range;
and
applying power to the remote device upon the third difference being in the predefined range.

11 more elements

Dependencies are inferred from the claim text.

Detection of devices on a local area network

Life of this patent

Detection of devices on a local area network

Life of this patent

Abstract

Claims12