Enabling/Disabling Power-Over-Ethernet Software Subsystem In Response To Power Supply Status

Abstract

An Ethernet switch includes 12-Volt and 48-Volt power sourcing modules, system software, Ethernet interface modules and optional power over Ethernet (PoE) modules. The Ethernet interface modules are motherboards that include the circuitry required to implement a non-PoE system. The PoE modules are daughter boards that include the circuitry required to supply powered devices in a PoE subsystem. A PoE module may be connected to a corresponding Ethernet interface module. During start up, all of the Ethernet interface modules are first powered up in response to the 12-Volt power sourcing module. If the system software subsequently determines that the 48-Volt power sourcing module is operational, then (and only then) the system software attempts to detect the presence of any PoE modules. Upon detecting one or more PoE modules, the PoE modules are initialized and configured, thereby enabling PoE operation.

1 . An interface module for an Ethernet switch comprising:
 a printed circuit board having a first connector element for receiving a first supply voltage and a second supply voltage, and a second connector element for receiving a daughterboard;   a digital system on the printed circuit board, wherein the digital system is powered by the first supply voltage;   a power over internet (PoE) module located on a daughterboard inserted into the second connector element of the printed circuit board, wherein the PoE module is powered by the second supply voltage; and   one or more Ethernet ports, each coupled to the digital system and the PoE module by the printed circuit board.   
     
     
         2 . The interface module of  claim 1 , wherein the PoE module provides the second supply voltage to one of the one or more Ethernet ports. 
     
     
         3 . The interface module of  claim 1 , wherein the second supply voltage is greater than the first supply voltage. 
     
     
         4 . The interface module of  claim 1 , wherein the PoE module supports powered devices coupled to the one or more Ethernet ports. 
     
     
         5 . The interface module of  claim 4 , wherein the digital system does not include a PoE subsystem to support powered devices coupled to the one or more Ethernet ports. 
     
     
         6 . The interface module of  claim 1 , wherein the first connector element is configured to be inserted into a corresponding connector element on a backplane of the Ethernet switch. 
     
     
         7 . An interface module for an Ethernet switch comprising:
 a printed circuit board having a first connector element that receives a first supply voltage, and a second connector element configured to receive a daughterboard containing a power over Ethernet (PoE) module;   a digital system on the printed circuit board, wherein the digital system is powered by the first supply voltage; and   one or more Ethernet ports, each coupled to the digital system and the second connector element by the printed circuit board.   
     
     
         8 . The interface module of  claim 7 , further comprising a daughterboard including a PoE module inserted into the second connector element of the printed circuit board. 
     
     
         9 . The interface module of  claim 8 , wherein the first connector element also receives a second supply voltage, wherein the PoE module is powered by the second supply voltage received by the first connector element. 
     
     
         10 . The interface module of  claim 9 , wherein the PoE module provides the second supply voltage to one of the one or more Ethernet ports. 
     
     
         11 . The interface module of  claim 9 , wherein the second supply voltage is greater than the first supply voltage. 
     
     
         12 . The interface module of  claim 8 , wherein the PoE module supports powered devices coupled to the one or more Ethernet ports. 
     
     
         13 . The interface module of  claim 7 , wherein the first connector element is configured to be inserted into a corresponding connector element on a backplane of the Ethernet switch. 
     
     
         14 . A method of constructing an interface module for an Ethernet switch comprising:
 providing an interface module having one or more Ethernet ports, wherein the interface module only supports non-power over Ethernet (non-PoE) devices coupled to the one or more Ethernet ports, wherein the interface module includes a connector element; and   inserting a power over Ethernet (PoE) module into the connector element of the interface module, wherein the PoE module supports powered devices coupled to the one or more Ethernet ports.   
     
     
         15 . An Ethernet switch comprising:
 a first interface module having a plurality of Ethernet ports, wherein the first interface module only supports non-power over Ethernet (non-PoE) devices;   a second interface module having a plurality of Ethernet ports, wherein the second interface module supports power over Ethernet (PoE) devices, and wherein the second interface module is identical to the first interface module, except for a PoE module that is inserted into a connector element of the second interface module.   
     
     
         16 . The Ethernet switch of  claim 15 , wherein the first and second interface modules each include a connector element for receiving a PoE module. 
     
     
         17 . The Ethernet switch of  claim 16 , further comprising:
 a first power supply module that provides a first supply voltage to the first and second interface modules, wherein the first interface module is powered by the first supply voltage; and   a second power supply module that provides a second supply voltage to the first and second interface module, wherein the PoE module of the second interface module is powered by the second supply voltage.   
     
     
         18 . The Ethernet switch of  claim 17 , wherein the PoE module provides the second supply voltage to one or more of the Ethernet ports of the second interface module. 
     
     
         19 . The Ethernet switch of  claim 17 , wherein the second supply voltage is greater than the first supply voltage. 
     
     
         20 . The Ethernet switch of  claim 17 , wherein a portion of the second interface module is powered by the first supply voltage.