First and second communication protocol arrangement for driving primary and secondary devices through a single port

1. A surgical instrument, comprising:

a first control circuit configured to allow the surgical instrument to communicate with an energy module using at least a first protocol over a first communication line; and

a second control circuit configured to allow the surgical instrument to communicate with one or more other surgical instruments, the one or more other surgical instruments coupled to the surgical instrument using at least a second protocol over a second communication line, wherein communications between the energy module and the one or more other surgical instruments are transmitted to the second control circuit via the first control circuit, wherein the second control circuit is connected in series with the first control circuit.

2. The surgical instrument of claim 1 , wherein the first control circuit comprises:

a communication logic circuit coupled to the first communication line and to the second control circuit;

a local processor coupled to the communication logic circuit; and

a multiplexer having inputs coupled to the local processor and the second control circuit, and an output coupled to the communication logic circuit.

3. The surgical instrument of claim 2 , wherein the communication logic circuit is configured to:

receive a message from the energy module over the first communication line;

provide a recognized message to the local processor for local processing; and

provide an unrecognized message to the second control circuit for processing.

4. The surgical instrument of claim 3 , wherein the local processor is configured to provide the processed recognized message to an input of the multiplexer and the output of the multiplexer is provided to the energy module over the first communication line.

5. The surgical instrument of claim 3 , wherein the second control circuit is configured to provide the processed unrecognized message to an input of the multiplexer and the output of the multiplexer is provided to the energy module over the first communication line.

6. The surgical instrument of claim 3 , wherein the second control circuit is configured to receive messages from the one or more other surgical instruments over the second communication line.

7. The surgical instrument of claim 6 , wherein the second control circuit is configured to provide the received messages to an input of the multiplexer and the output of the multiplexer is provided to the energy module over the first communication line.

8. The surgical instrument of claim 1 , wherein the second protocol is synchronized to the first protocol.

9. A communication circuit, in a primary surgical instrument comprising:

a first control circuit configured to allow the primary surgical instrument to communicate with an energy module using at least a first protocol over a first communication line; and

a second control circuit configured to allow the primary surgical instrument to communicate with one or more secondary surgical instruments, the one or more secondary surgical instruments coupled to the communication circuit using at least a second protocol over a second communication line;

wherein the first control circuit comprises:

a communication logic circuit coupled to the first communication line and to the second control circuit;

a local processor coupled to the communication logic circuit; and

a multiplexer having inputs coupled to the local processor and the second control circuit, and an output coupled to the communication logic circuit;

wherein the communication logic circuit is configured to:

receive a message from the energy module over the first communication line;

provide a recognized message to the local processor for local processing; and

provide an unrecognized message to the second control circuit for processing.

10. The communication circuit of claim 9 , wherein the local processor is configured to provide the processed recognized message to an input of the multiplexer and the output of the multiplexer is provided to the energy module over the first communication line.

11. The communication circuit of claim 9 , wherein the second control circuit is configured to provide the processed unrecognized message to an input of the multiplexer and the output of the multiplexer is provided to the energy module over the first communication line.

12. The communication circuit of claim 9 , wherein the second control circuit is configured to receive messages from the one or more secondary surgical instruments over the second communication line.

13. The communication circuit of claim 12 , wherein the second control circuit is configured to provide the received messages to an input of the multiplexer and the output of the multiplexer is provided to the energy module over the first communication line.

14. A communication circuit, in a primary surgical instrument comprising:

a control circuit;

a potentiometer circuit coupled to the control circuit;

a switch circuit coupled to the control circuit and the potentiometer circuit; and

an adjustable control filter;

wherein the control circuit is configured to communicate with one or more secondary surgical instruments using a first and second communication protocol over a single communication line, wherein the adjustable control filter is coupled to the single communication line, and wherein the first communication protocol is used to communicate with a first device, and the second communication protocol is configured to communicate to at least one secondary device through the first device.

15. The communication circuit of claim 14 , further comprising an analog-to-digital converter (ADC) coupled to the control circuit and the adjustable control filter, wherein the ADC is configured to convert an output of the adjustable control filter and provide a digital version of the output of the adjustable control filter to the control circuit.

16. The communication circuit of claim 14 , wherein the control circuit is configured to control the potentiometer circuit by setting a resistance value.

17. The communication circuit of claim 14 , wherein the potentiometer circuit comprises a first and second resistor.

18. The communication circuit of claim 14 , wherein the switch circuit comprises a first and second switch.

19. The communication circuit of claim 18 , wherein the potentiometer circuit comprises a first and second resistor; and

the first switch is coupled between the control circuit and the first resistor; and

the second switch is coupled between the control circuit and the second resistor.

20. The communication circuit of claim 18 , wherein the control circuit is configured to control the state of the first and second switches to set the current delivered into the adjustable control filter.

21. The communication circuit of claim 18 , wherein the potentiometer circuit comprises a digital potentiometer circuit.

22. The communication circuit of claim 18 , wherein the potentiometer circuit comprises a digital-to-analog converter (DAC) circuit.