Electronic identification tag interrogation method

An electronic identification tag interrogation system comprising:

• (a) at least one portal having transmitter means for providing an RF signal and receiver means for responding to an RF tag signal having identifying data encoded therein;
• (b) at least one electronic identification tag having supply means for providing electrical power to said tag, memory means for storing identifying data associated with said tag, RF receiver means powered by said supply means for processing an RF signal, and RF transmitter means for transmitting identifying data stored in said memory means in response to the receipt by said RF receiver means of an RF signal having a request encoded therein, said at least one electronic identification tag provided with a discrete identification number;
• (c) interrogation means for searching said identification number of said at least one electronic identification tag;
• (d) means provided on said at least one portal for acknowledging receipt of a single response from said at least one electronic identification tag;
• and
• (e) means for suppressing further replies from said acknowledged electronic identification tag in response to further interrogation signals, wherein said means for suppressing further replies comprises a signal transmitted by said portal and received by said electronic identification tag instructing said electronic identification tag not to response to further interrogation signals.

An electronic identification tag interrogation method comprising the steps of:

• providing at least two electronic identification tags with a discrete identification number;
• transmitting a request from a portal for all said at least two identification tags having an identification number within a desired address range to respond;
• continuously bisecting said desired address range until only one of said at least two identification tags responds to said request;
• and
• acknowledging said one of said at least two identification tags.

An electronic identification tag interrogation method comprising the steps of:

• providing at least two electronic identification tags with discrete identification numbers;
• transmitting a request from a portal for all said at least two identification tags having an identification number within a desired address range to respond;
• continuously bisecting said desired address range until only one of said at least two identification tags responds to said request;
• acknowledging said one of said at least two identification tags;
• instructing said acknowledged tag to suppress responding to further interrogation requests until all remaining said at least two electronic identification tags are acknowledged;
• and
• shifting said acknowledged tag to a lower power mode in which it periodically detects whether an interrogation signal is present.