Tool identification system

Provision is made for identifying tools used in an automated machine tool system. A module or transponder is mounted to the tool and interrogated by a transceiver which, in the preferred embodiments, has read/write capabilities. The transponder uses energy from the transmitted signal to power itself and send information stored in its memory back to the transceiver. In one embodiment, electromagnetic energy is transmitted from the transceiver to the transponder while the transponder to transceiver communication link is provided by way of capacitive coupling.

What is claimed is:

1. A method comprising:

mounting a transponder in a tool, said transponder including a read/write memory having a unique identification code stored therein, the memory requiring clock, chip select, and data operation signals to be applied thereto for proper operation;

placing said tool in a temporary storage device;

wirelessly transmitting from a transceiver an encoded waveform containing sufficient power and encoded operation signals to the transponder to power and operate the memory, the waveform always at least including a repetitively generated clock code impressed therein;

using the clock code impressed in the waveform received by the transponder to define a plurality of time slots;

sensing the waveform during said time slots for the presence of codes associated with said chip select and data signals;

applying decoded chip select, clock and data signals to the memory to read the identification code therein;

transmitting the identification code from the memory in the transponder to the transceiver;

comparing the identification code with preselected information; and

loading said tool into a machine for performing operations on a workpiece as a result of said comparison.

2. The method of claim 1 which further comprises:

removing the tool from the machine after it has performed operations on the workpiece;

using the transceiver to electromagnetically transmit sufficient power and operation signals to write information into the transponder memory; and

returning the tool to the storage device.

3. The method of claim 2 wherein said information written into the memory is a function of the expected remaining useful life of the tool.

4. The method of claim 1 wherein information relating to the maximum feed rate for the tool is also contained within said memory.

5. The method of claim 1 wherein the maximum speed for the tool is also programmed into said memory.

6. The method of claim 1 wherein said waveform is encoded by selectively shifting the frequency of a reference signal at given time periods, and wherein said identification code is defined by dividing a given frequency of the received waveform by given numbers depending upon the logical level of the information contained within the memory.

7. The method of claim 1

wherein the encoded waveform from the transceiver is in the form of electromagnetic energy; and

wherein the identification code transmitted from the memory in the transponder is in the form of electrostatic energy.

8. The method of claim 7

wherein said transponder is mounted in an adapter portion of a machine tool; and

wherein said transceiver is mounted on a tool magazine which holds a plurality of different tools.

9. The method of claim 8 wherein said transponder is implanted into the tool adapter so that electronic components in the transponder are referenced to the same electrical potential as electrical components in the transceiver.

10. The method of claim 1

wherein said waveform is encoded by periodically shifting the frequency of a reference signal to generate first and second clock signals;

wherein said chip select signal is encoded in the waveform by additionally shifting the reference frequency during a first preselected time slot between the first and second clock signals; and

wherein data of a given digital state is defined by additionally shifting the reference frequency during a second time slot between the first and second clock signals, with the absence of a frequency shift in the second time slot defining an opposite digital data state.

11. An identification system comprising a transceiver and a transponder, said transponder including a read/write memory requiring chip select, clock and data operation signals applied thereto for operating the memory;

said transceiver including oscillator means for generating a reference alternating current signal, modulator means for shifting the frequency of the reference signal in accordance with certain input control signals, said input control signals being adapted to shift the frequency of the reference signal at first and second times to generate first and second clock codes, the modulator means being further adapted to selectively shift the frequency of the reference signal during a first time slot between the first generation of the first and second clock codes thereby defining a chip select code, with the modulator means further being adapted to selectively shift the frequency of the reference signal during a second time slot between the first and second clock codes thereby defining a data code for one digital state; and

said transponder including a divider means responsive to the generation of said clock codes to generate first and second time slots, said transponder further including decoder means for detecting the presence of the shifted frequency at said first time slot to thereby decode the chip select signal from the waveform, said decoder means being further adapted to detect the shifted frequency of the waveform during said second time slot to thereby decode data of said one digital state; and said transponder further including means for supplying decoded clock, data and chip select signals to said memory to control the operation thereof.