Patent ID: 7656888

Claim:
A bi-directional detector for enabling a host part and clients to detect whether the host part and the clients are electronically interconnected to each other in a collection terminal, the bi-directional detector comprising: a client detection unit in the host part for detecting at least one of a plurality of clients connected to the host part; a client identification unit for identifying types of the clients detected by the client detection unit; a host detection unit in each of the plurality of clients for detecting the host part and attempting a connection with the host part without waiting for a response from the host part; a switch unit in each of the clients for determining whether to apply comparison power to the client detection unit and the host detection unit according to whether power is applied to the client; a first interface unit in the host part; and a second interface unit in each of the plurality of clients; wherein the host part and the clients detect each other via the first interface unit and the second interface unit, and wherein the switch unit comprises an identification resistor having different values according to types of client devices connected to the plurality of clients, and a transistor connected between the identification resistor and a ground for grounding the identification resistor when the power is applied to the client.