System and method for using a shared bus for video communications

• US 20030200345A1
• Filed: 04/17/2002
• Published: 10/23/2003
• Est. Priority Date: 04/17/2002
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Masuyama, Jinsaku, Kolb, Michael W., Ramsey, Scott M.
• Granted Patent: US 7,398,293 B2
• Time in Patent Office: Days
• US Class Current: 709/253
• CPC Class Codes: H04N 21/226 Characteristics of the server or Internal components of the server

Abstract

A system and method for using a shared bus to control a keyboard, video, and mouse (KVM) output is disclosed. The system may include a mid-plane having a video bus. At least one server module, including a video output module, may be placed in communications with the video bus. The video output module may transmit a video signal over the bus and receives a control signal over the bus. A management module may also be placed in communications with the video bus. The management module may receive the video signal from the server module via the bus and provide a control signal through the video bus to each server module. The control signal may activate or deactivate the video output module on each server module.

Claims

1. A computer system, comprising:

a mid-plane including a video bus;

at least one server module including a video output module in communication with the video bus, the video output module operable to transmit a video signal over the video bus and to receive control signals from the video bus; and

a management module in communication with the video bus, the management module operable to receive the video signal from each server module via the video bus and to provide the control signals through the video bus to each server module to activate and deactivate the video output module on each server module.

2. The computer system of claim 1, further comprising:

a keyboard, video, and mouse (KVM) module in the server module, wherein the KVM module includes;

the video output module;

a keyboard input module; and

a mouse input module.

3. The computer system of claim 1, wherein each server module further comprises:

a signal generator on the video output module; and

a control switch on the video output module, the control switch operable to activate or deactivate the signal generator in response to the control signal from the management module.

4. The computer system of claim 1, wherein each server module further comprises a unique address based on a location where the server module couples to the midplane, the unique address operable to identify each server module to control the video output module.

5. The computer system of claim 1, wherein the mid-plane comprises a back-plane.

6. The computer system of claim 1, wherein the mid-plane comprises a circuit board that includes a plurality of connectors operable to provide an interface between the server module and the mid-plane.

7. The computer system of claim 1, wherein the video bus comprises a serial bus connection including at least two conductors that carry the control signal.

8. The computer system of claim 1, wherein the management module further comprises:

a video output connection operable to drive a video display device based on the video signals from the server module; and

a video selection unit controller card operable to provide the control signal to the server modules.

9. An information handling system, comprising:

a server module communicatively coupled to a bus;

means for receiving control signals from the bus at the server module;

means for determining whether the control signals are addressed to the server module; and

means for enabling and disabling production of video output in the server module in response to the control signals.

10. An information handling system, comprising:

a server module communicatively coupled to a bus;

a unique address associated with the server module based on a location of the server module in the information handling system, the unique address operable to identify the server module;

a video output module in the server module, the video output module operable to transmit video signals to the bus; and

a controller switch in the server module, the controller switch operable to receive control signals from the bus and enable and disable transmission of video signals from the video output module in response to the control signals.

11. The information handling system of claim 10, further comprising:

an external management module communicatively coupled to the bus;

one or more additional server modules communicatively connected to the external management module via the bus;

a server selection engine in the external management module operable to receive user input selecting one of the server modules to drive a display device; and

a video selection unit in the external management module operable to provide the control signals in response to the user input, wherein the control signals cause only the selected server module to transmit video signals via the bus.

12. The information handling system of claim 10, further comprising:

a server rack with a mid-plane communicatively connected to the video output module;

an external management module communicatively connected to the mid-plane;

a video output connection in the external management module operable to drive a display device based on the video signals from the server module; and

a video selection unit in the external management module operable to provide the control signals to the server module.

13. A method of using a shared bus to control video output in a computer system, the method comprising:

receiving a control signal at a server module from a management module via a bus; and

transmitting a video output signal from the server module to the management module via the bus, in response to the control signal.

14. The method of claim 13, further comprising:

receiving user input at the management module to select the server module to drive a display device.

15. The method of claim 13, further comprising:

producing output on a display device connected to the management module, based on the video output signal.

16. The method of claim 13, further comprising:

assigning a unique address for the server module, based on a location of the server module in a server rack containing the server module.

17. The method of claim 13, wherein the server module comprises a first server module and the control signal comprises a first control signal, the method further comprising:

transmitting a second control signal to disable the video output signal from the first server module; and

transmitting a third control signal after the second control signal to enable video output from a second server module.

18. The method of claim 13, wherein the video output signal comprises a keyboard, video and mouse (KVM) signal transmitted along the bus.

19. The method of claim 13 wherein the server module comprises a first server module in a plurality of server modules;

and

the method further comprising allowing a user at a single video output connection to select which of the multiple server modules will transmit video output to the single video output module via the bus.

20. The method of claim 13, further comprising reducing an impedance level of a video output generator in the server module to enable transmission of the video output signal.