초록 ▼

A switch control circuit is provided in a dual speed stackable networking device for automatically bypassing a faulty exchanging unit and monitoring the voltages of the associated input end and output end to prevent the occurrence of a traffic loop. When a number of dual-speed hubs are arranged in a

A switch control circuit is provided in a dual speed stackable networking device for automatically bypassing a faulty exchanging unit and monitoring the voltages of the associated input end and output end to prevent the occurrence of a traffic loop. When a number of dual-speed hubs are arranged in a stack, the output end of the current switch control circuit is coupled to the input end of a switch control circuit of next adjacent dual-speed hub. On the other hand, the output end of the current switch control circuit is coupled to the input end of a switch control circuit of another adjacent dual-speed hub. The switch control circuit includes a detector for detecting the power status of the exchanging unit, a logic unit for controlling the voltages of the input end and the output end. If the exchanging unit is not functioning normally, and the voltage of the output end is set to 0, then the exchanging unit is disabled by the switch control circuit. According to the control of the switch control circuit, each dual speed stackable networking device will be automatically bypassed if it is powered off. The traffic loop can thus be efficiently avoided without having to implement the Spanning Tree Protocol in a CPU.

대표청구항 ▼

1. A dual-speed stackable networking device comprising:a first repeater connecting to a port of a first data transfer rate; a second repeater connecting to a port of a second data transfer rate; an exchanging unit connected to said first repeater and said second repeater for automatically exchanging

1. A dual-speed stackable networking device comprising:a first repeater connecting to a port of a first data transfer rate; a second repeater connecting to a port of a second data transfer rate; an exchanging unit connected to said first repeater and said second repeater for automatically exchanging packets between said first repeater and said second repeater; and a switch control circuit (Ln) for enabling/disabling said exchanging unit in response to voltage of an input end and a power status of said exchanging unit, the switch control circuit comprising, means for detecting a power status of said exchanging unit to determine if said exchanging unit is powered-on and setting an output voltage of said switch control circuit to high when said exchanging unit is powered-on and setting said output voltage of said switch control circuit to low when said exchanging unit is powered-off, and means for enabling/disabling said exchanging unit in response to an input voltage of said switch control circuit, the means for enabling/disabling will disable said exchanging unit when said input voltage of said switch control circuit is high.