Method and apparatus for changing power class for a powered device

A powered device configured to receive a first amount of power from a power source, via a communication medium, based upon a first classification signal provided to the power source by the powered device, the powered device configured to:

• detect an electrical coupling of a modular powered device to the powered device;
• provide a second classification signal to the power source based upon the electrical coupling of the modular powered device;
• receive a second amount of power from the power source, via the communication medium, based upon the second classification signal, the second amount of power being greater than the first amount of power;
• and
• provide a portion of the second amount of power to the modular powered device;
• wherein the powered device, when detecting, is configured to:
• detect a current produced by a classification circuit of the powered device, the classification circuit configured to electrically couple with the modular powered device;
• compare the measured current against a threshold value to form a result;
• detect the absence of a connection to the modular powered device when the result has a first value;
• and
• detect the presence of a connection to the modular powered device when the result has a second value, the second value different than the first value.

In a power source, a method for providing power to a powered device, comprising:

• providing a first amount of power to a powered device;
• receiving a classification signal from the powered device, the classification signal representing a request for a second amount of power, the second amount of power being greater than the first amount of power;
• performing a powered device classification procedure to detect (i) a power classification of the powered device and (ii) a second amount of power corresponding to the power classification of the powered device;
• and
• transmitting the second amount of power to the powered device;
• wherein:
• receiving comprises exchanging a modulated current as the second classification signal between the power source and the powered device, the modulated current being modulated to an over current value and over a time interval that is less than an over current duration threshold, the over current value being indicative of an over current condition in the powered device and the over current duration threshold being of a duration that causes the power source to cease transmission of power to the first powered device;
• and
• performing comprises decoding a pattern of the modulated over current to detect the power classification of the powered device and the second amount of power to be transmitted to the powered device, the second amount of power corresponding to the power classification of the powered device.

A power source configured to provide power to a powered device, the power source comprising a controller configured to:

• provide a first amount of power to a powered device;
• receive a classification signal from the powered device, the classification signal representing a request for a second amount of power, the second amount of power being greater than the first amount of power;
• perform a powered device classification procedure to detect (i) a power classification of the powered device and (ii) a second amount of power corresponding to the power classification of the powered device;
• and
• transmit the second amount of power to the powered device;
• wherein the power source is configured to:
• when receiving, exchange a modulated current as the second classification signal between the power source and the powered device, the modulated current being modulated to an over current value and over a time interval that is less than an over current duration threshold, the over current value being indicative of an over current condition in the powered device and the over current duration threshold being of a duration that causes the power source to cease transmission of power to the first powered device;
• and
• when performing, decode a pattern of the modulated over current to detect the power classification of the powered device and the second amount of power to be transmitted to the powered device, the second amount of power corresponding to the power classification of the powered device.

A data communications system, comprising:

• a power source;
• and
• a powered device configured to receive a first amount of power from the power source, via a communication medium, based upon a first classification signal provided to the power source by the powered device,
• wherein the powered device is configured to:
• detect an electrical coupling of a modular powered device to the powered device,
• provide a second classification signal to the power source based upon the electrical coupling of the modular powered device,
• wherein the power source is configured to:
• receive the classification signal from the powered device, the classification signal representing a request for a second amount of power, the second amount of power being greater than the first amount of power,
• perform a powered device classification procedure to detect (i) a power classification of the powered device and (ii) a second amount of power corresponding to the power classification of the powered device, and
• transmit the second amount of power to the powered device;
• wherein the powered device, when detecting, is configured to:
• detect a current produced by a classification circuit of the powered device, the classification circuit configured to electrically couple with the modular powered device;
• compare the measured current against a threshold value to form a result;
• detect the absence of a connection to the modular powered device when the result has a first value;
• and
• detect the presence of a connection to the modular powered device when the result has a second value, the second value different than the first value.

In a power source, a method for providing power to a powered device, comprising:

• providing a first amount of power to a powered device;
• receiving a classification signal from the powered device, the classification signal representing a request for a second amount of power, the second amount of power being greater than the first amount of power;
• performing a powered device classification procedure to detect (i) a power classification of the powered device and (ii) a second amount of power corresponding to the power classification of the powered device;
• and
• transmitting the second amount of power to the powered device;
• wherein:
• receiving comprises (i) receiving a disable command from the powered device, the disable command disabling a connection with the power source and (ii) receiving a series of link pulses from the powered device to re-establish the connection using an auto-negotiation mechanism, at least one of the series of link pulses forming the second classification signal;
• and
• performing comprises decoding a pattern of the at least one of the series of link pulses to detect the power classification of the powered device and the second amount of power to be transmitted to the powered device, the second amount of power corresponding to the power classification of the powered device.

A power source configured to provide power to a powered device, the power source comprising a controller configured to:

• provide a first amount of power to a powered device;
• receive a classification signal from the powered device, the classification signal representing a request for a second amount of power, the second amount of power being greater than the first amount of power;
• perform a powered device classification procedure to detect (i) a power classification of the powered device and (ii) a second amount of power corresponding to the power classification of the powered device;
• and
• transmit the second amount of power to the powered device;
• wherein the power source is configured to:
• when receiving, (i) receive a disable command from the powered device, the disable command disabling a connection with the power source and (ii) receive a series of link pulses from the powered device to re-establish the connection using an auto-negotiation mechanism, at least one of the series of link pulses forming the second classification signal;
• and
• when performing, decode a pattern of the at least one of the series of link pulses to detect the power classification of the powered device and the second amount of power to be transmitted to the powered device, the second amount of power corresponding to the power classification of the powered device.