Computer interconnection system having analog overlay for remote control of the interconnection switch

• US 6,112,264 A
• Filed: 02/04/1999
• Issued: 08/29/2000
• Est. Priority Date: 08/25/1995
• Status: Expired due to Term

• Current Assignee: Avocent Redmond Corporation (Emerson Electric Company)
• Original Assignee: Apex PC Solutions, Inc. (Vertiv Holdings Co.)
• Inventors: Lacrampe, Paul, Greene, Thomas, Huffington, James C., Hafer, Kevin J., Beasley, Danny L., Seifert, Robert V. Jr.
• Primary Examiner(s): Dinh, Dung C.
• Application Number:
  US09/244,947
• Time in Patent Office: 572 Days
• Field of Search: 345/113, 345/326, 345/327, 345/329, 345/1, 345/2, 345/4, 345/7, 345/9, 710/15, 710/38, 710/2, 710/51, 710/131, 348/552, 348/584, 348/589
• US Class Current: 710/38
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 15/17375 One dimensional, e.g. linear array, ring
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/561 Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 67/567 Integrating service provisioning from a plurality of service providers
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

A computerized switching system for coupling a workstation to a remotely located computer. A signal conditioning unit receives keyboard and mouse signals generated by a workstation and generates a data packet which is transmitted to a central crosspoint switch. The packet is routed through a crosspoint switch to another signal conditioning unit located at a remotely located computer. The second signal conditioning unit applies the keyboard and mouse commands to the keyboard and mouse connectors of the computer as if the keyboard and mouse were directly coupled to the remote computer. Video signals produced by the remote computer are transmitted through the crosspoint switch to the workstation. Horizontal and vertical sync signals are encoded on to the video signals to reduce the number of cables that extend between the workstation and the remote computer. The signal conditioning units connected to the workstations include an onscreen programming circuit that produces menus for the user on a video display of the workstation.

Claims

1. A switching system comprising:

a computer-side interface for simultaneously physically connecting to independent, dedicated cables of respective keyboard and analog video outputs of plural computers;

a user-side interface for physically connecting to a first set of independent, dedicated cables of a first keyboard and an analog video input of a first monitor;

an analog video receiving circuit, connected to the computer-side interface, for receiving analog video signals from one of the plural computers through the computer-side interface;

an analog video overlay image generating circuit, disposed between the computer-side interface and the user-side interface, for producing an analog overlay video signals internal to the switching system; and

an analog video overlay circuit, disposed between the computer-side interface and the user-side interface, for combining (1) a portion of the analog video signals received by the analog video receiving circuit and (2) the analog overlay video signals generated internally to the switching system to form a combined analog signal that is output to the first monitor via the user-side interface.

2. The system as claimed in claim 1, wherein the analog video receiving circuit further comprises a synchronization signal detecting circuit for detecting one of a horizontal- and a vertical-synchronization signal corresponding to the analog video signals from the one of the plural computers.

3. The system as claimed in claim 1, wherein the computer-side interface further comprises a computer-side mouse interface for transceiving signals to and from mouse ports of the plural computers, and

wherein the user-side interface further comprises a user-side mouse interface for transceiving signals to and from a first computer mouse.

4. The system as claimed in claim 1, wherein the analog video overlay circuit comprises a multiplexer for multiplexing (1) the portion of the analog video signals received by the analog video receiving circuit and (2) the analog overlay video signals generated internally to the switching system without requiring a frame buffer.

5. The system as claimed in claim 1, further comprising a keyboard translator disposed between the computer-side and the user-side interfaces for translating a keyboard code from a first format used on the user-side to a second format used on the computer-side.

6. The system as claimed in claim 1, wherein the analog video receiving circuit receives separate analog red, green and blue signals.

7. The system as claimed in claim 2, wherein the analog video receiving circuit comprises a receiving circuit for receiving real-time, analog video signals.

8. The system as claimed in claim 2, wherein the analog video receiving circuit comprises a receiving circuit for receiving real-time, analog video signals including the at least one of the horizontal- and a vertical-synchronization signal superimposed on the real-time, analog video signals.

9. The system as claimed in claim 7, wherein the analog video receiving circuit receives separate analog red, green and blue signals.

10. The system as claimed in claim 8, wherein the analog video receiving circuit receives separate analog red, green and blue signals.

11. The system as claimed in claim 1, further comprising:

a digital backplane; and

an analog backplane, wherein keyboard information is routed from the computer-side interface to the user-side interface on the digital backplane independent of the analog video signals that are routed from the computer-side interface to the user-side interface on the analog backplane.

12. The system as claimed in claim 1, wherein the computer-side interface comprises a parallel switch for connecting the plural computers to the computer-side interface in parallel.

13. The system as claimed in claim 1, wherein the user-side interface further comprises a secondary user-interface for connecting to a second set of independent, dedicated cables of a second keyboard and an analog video input of a second monitor, wherein the analog video signals of any one of the plural computers can be routed simultaneously to both the first and second monitors in parallel.

14. The system as claimed in claim 1, further comprising a keyboard command detector, disposed between the computer-side interface and the user-side interface, for detecting when the first keyboard requests that the analog video signals of the one of the plural computers be replaced by analog video signals of another of the plural computers.

15. The system as claimed in claim 14, further comprising:

a digital backplane; and

an analog backplane, wherein keyboard information is routed from the computer-side interface to the user-side interface on the digital backplane independent of the analog video signals that are routed from the computer-side interface to the user-side interface on the analog backplane.

16. The system as claimed in claim 1, further comprising a keyboard command detector, disposed between the computer-side interface and the user-side interface, for detecting when the first keyboard requests that the analog video signals of the one of the plural computers be replaced by analog video signals of another of the plural computers in response to the combined analog signal that is output to the first monitor via the user-side interface.

17. The system as claimed in claim 16, further comprising:

a digital backplane; and

an analog backplane, wherein keyboard information is routed from the computer-side interface to the user-side interface on the digital backplane independent of the analog video signals that are routed from the computer-side interface to the user-side interface on the analog backplane.