KVM switch including a terminal emulator

• US 7,321,943 B2
• Filed: 09/19/2006
• Issued: 01/22/2008
• Est. Priority Date: 08/25/1999
• Status: Expired due to Term

• Current Assignee: Vertiv IT Systems, Inc. (Vertiv Holdings Co.)
• Original Assignee: Avocent Redmond Corporation (Emerson Electric Company)
• Inventors: Shirley, Timothy C.
• Primary Examiner(s): Yang; Ryan
• Application Number:
  US11/522,928
• Publication Number:
  US 20070013656A1
• Time in Patent Office: 490 Days
• Field of Search: 710/62, 710/100, 345/520
• US Class Current: 710/62
• CPC Class Codes: G06F 13/107 Terminal emulation
• CPC Class Codes: G06F 2203/0384 Wireless input, i.e. hardware and software details of wireless interface arrangements for pointing devices
• 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: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2370/24 Keyboard-Video-Mouse [KVM] switch
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04

Abstract

A method and system for converting the output of a communications port (e.g., a serial port or a USB port) into video signals representing the output of a terminal using a KVM switch. Upon receiving characters from the communications port, the system interprets the characters as terminal emulation commands and internally generates a representation of what a resulting terminal screen would look like. From that internal (digital) representation, the system produces analog outputS representing the terminal screen. The analog outputs are output on the monitor attached to the KVM switch.

Claims

1. A switch to communicate keyboard and video signals between a first remote target computer and a controlling user interface, comprising:

a target controller housing and (1) a plurality of target computer physical interfaces associated with the housing for coupling keyboard and video signals to or from the remote target computer via associated target computer interfaces and (2) a network physical interface associated with the housing for communication with a packet-based network;

a target controller within the target controller housing to translate keyboard and video signals between at least one of the target computer physical interfaces and the network physical interface; and

a target controller communication device for communicating the keyboard and video signals using a packet-based communication protocol on the network physical interface wherein the controlling user interface operates to control the first remote target computer via a communication path including, in sequence, the network physical interface utilizing the packet-based communication protocol, the target controller, at least one of the target computer physical interfaces utilizing a computer peripheral protocol understood by the controlling user interface and different from the packet-based communication protocol, and the controlling user interface.

2. The switch as claimed in claim 1, wherein the target controller comprises plural bitmaps representing line-by-line representations of characters stored in the digital memory.

3. The switch as claimed in claim 1, wherein the target controller is implemented in a field-programmable gate array.

4. The switch as claimed in claim 3, further comprising a configuration memory, wherein the field-programmable gate array is dynamically loaded with a configuration, from the configuration memory, corresponding to a type of terminal to be emulated.

5. The switch as claimed in claim 1, wherein the network physical interface receives commands for a text-based terminal.

6. The switch as claimed in claim 1, wherein the network physical interface receives commands for a graphics-based terminal.

7. The switch as claimed in claim 1, wherein the network physical interface comprises a wired network physical interface.

8. The switch as claimed in claim 1, wherein the network physical interface comprises an Ethernet interface.

9. The switch as claimed in claim 1, wherein the network physical interface comprises an RS-232 interface.

10. The switch as claimed in claim 1, wherein the network physical interface comprises a serial interface.

11. The switch as claimed in claim 1, wherein the network physical interface comprises a USB interface.

12. The switch as claimed in claim 1, wherein the network physical interface comprises a Token ring interface.

13. The switch as claimed in claim 1, wherein the network physical interface comprises an ATM interface.

14. The switch as claimed in claim 1, wherein the network physical interface comprises a wireless communications interface.

15. The switch as claimed in claim 1, wherein the network physical interface comprises an RF communications interface.

16. The switch as claimed in claim 1, wherein the network physical interface comprises an IR communications interface.