System and method for accessing and operating personal computers remotely

• US 20030217123A1
• Filed: 04/30/2003
• Published: 11/20/2003
• Est. Priority Date: 09/22/1998
• Status: Active Grant

• Current Assignee: Vertiv IT Systems, Inc. (Vertiv Holdings Co.)
• Original Assignee: Avocent Huntsville Corporation (Vertiv Holdings Co.)
• Inventors: Anderson, Robin L., Perholtz, Ronald J., Hawkins, Dennis
• Granted Patent: US 7,349,956 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• 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 3/1454 involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay
• CPC Class Codes: H04L 67/125 involving control of end-device applications over a network

Abstract

A remote access device is disclosed for capturing, digitizing and communicating video signals from a host computer to a remote computer. The remote computer returns keyboard and mouse signals through the remote access device to the host computer to control the host computer as though the remote keyboard and mouse were directly connected to the host computer. The remote access device includes a circuit module interface for the host computer that allows the remote access device to operate independently of any operating system characteristics associated with the host computer.

Claims

1. A circuit module for a remote access computer, having in operation therein a remote access engine, to communicate between a data bus and the remote access engine, comprising:

a video capture circuit to capture analog video signals created by an external host computer different from the remote access computer, to digitize and packet the captured video signals; and

to sync the captured video signals to a video output on an external remote site computer different from the external host computer;

a keyboard/mouse circuit to capture user input signals identifying at least one from the group consisting of keyboard and mouse signals created by the external remote site computer and captured by the remote access engine from the external remote site computer when initiated by the external remote site computer via a network connection.

2. A circuit module according to claim 1, wherein the video capture circuit syncs the captured video signals by deducing a video format characteristic of the analog video signals created by the external host computer.

3. A circuit module according to claim 2, wherein the video format characteristic includes resolution information.

4. A circuit module according to claim 3, wherein the resolution information is created by a VGA card of the host computer.

5. A circuit module according to claim 1, wherein the host computer creates the analog video signals in cooperation with a particular type of operating system existing on the host computer, and the video capture circuit operates independently of the type of operating system existing on the host computer.

6. A circuit module according to claim 1, wherein the video capture circuit communicates with a standard video interface of the host computer.

7. A circuit module according to claim 6, wherein the video capture circuit operates independently of all software operation of the host computer except to receive the output of the standard video interface of the host computer.

8. A circuit module according to claim 7, wherein the video capture circuit syncs the captured video signals by deducing a video format characteristic of the analog video signals created by the external host computer.

9. A circuit module according to claim 1, further including:

a remote access interface cooperating with the remote access engine to deliver the synchronized and digitized video to the external remote site computer via a logical data path established between the remote access interface and the remote site computer.

10. A circuit module according to claim 1, wherein the remote access interface provides the remote site computer with a digitized version of the analog video signals created by the host computer for conversion and display at the remote site computer on essentially a real-time basis.

11. A circuit module for a computer having in operation therein a remote access engine to communicate between a host server and a remote workstation, comprising:

a main CPU to coordinate a digital to analog conversion of host video signals from the host server;

a field programmable gate array, in communication with the main CPU;

a video interface circuit, in communication with the field programmable gate array, to capture the host video signals for the main CPU and field programmable gate array;

a video RAM to store host video signals digitized by the main CPU and field programmable gate array, and to deliver the digitized video signals to the remote access engine for delivery to the remote computer, the video RAM in communication with the field programmable gate array to receive at least video sync processing from the field programmable gate array;

at least one of a mouse driver circuit and a keyboard driver circuit, in communication with the main CPU, to receive, respectively, mouse and keyboard information from the remote computer;

a bus controller, in communication with the field programmable gate array, to communicate information identifying the digitized host video signals and the mouse and keyboard information to the remote access engine.

12. A remote access computer installed between at least one host computer and a remote computer, the host computer having a particular type of operating system, the remote access computer comprising:

a video capture circuit connected to a standard video output connector of the host computer to receive an analog RGB video signal normally destined for a standard monitor associated with the host computer;

a keyboard/mouse interface connected to at least one of;

a standard keyboard input connector of the host computer to deliver a keyboard control signal normally delivered by a standard keyboard associated with the host computer; and

a standard mouse input connector of the host computer to deliver a mouse control signal normally delivered by a standard mouse associated with the host computer;

a video process circuit, in communication with the video capture circuit, to synchronize and digitize the analog RGB video signal received by the video capture circuit;

a network interface communicating with a network medium which is also communicating with the remote computer;

a video interface communicating with;

the video process circuit to receive the synchronized and digitized RGB video signal, and

the network medium to deliver the digitized RGB video signal to the remote computer to allow the remote computer user to view in essentially real-time the same RGB video signal as provided by the host computer; and

wherein;

the video capture circuit, keyboard/mouse interface, video process circuit, network interface, and video interface all operate independently of the particular type of operating system on the host computer.

13. A remote access system communicating with a digital network transmission medium to communicate user input signals from a remote computer to a host computer via the transmission medium and video signals from the host computer to the remote computer via the transmission medium, comprising:

a user input process to capture the user input signals for digital transmission to the host computer;

a video process to capture the video input signals, digitize them and format them for transmission to the remote computer, even when the host computer has locked up to no longer accept any user input signals;

a standard remote access engine;

to communicate the user input signals on the transmission medium between the host and remote computers, and

to communicate the video signals, in digital format, on the transmission medium between the host and remote computers, even when the host computer has locked up to no longer accept any user input signals.

14. A circuit module for a computer having in operation therein a remote access engine to communicate between a host server and a remote workstation, including:

video buffer circuits to receive, respectively, red, green and blue analog video signals from the host server;

sync polarity circuits to receive, respectively, horizontal and vertical sync signals from the host server;

analog to digital converters communicating with the video buffer circuits to receive the red, green and blue analog video signals and convert them to digital video signals;

a phase locked loop video dot clock circuit communicating with the sync polarity circuits and outputting a dot clock signal;

a TTL converter receiving the digital video signals and converting them to a TTL format; and

a video processing circuit, including a cpu and a programmable gate array, connected to the sync polarity circuits, the phase locked loop video dot clock circuit, and the TTL converter to automatically determine a graphics mode of the red, green and blue analog video signals.

15. A circuit module according to claim 14, wherein the programmable gate array includes circuitry to determine a video frame rate characteristic of the red, green and blue analog video signals.

16. A circuit module according to claim 14, wherein the graphics mode includes a number of available colors.

17. A circuit module according to claim 14, wherein the graphics mode includes a screen resolution in horizontal pixels per screen by vertical pixels per screen.

18. A circuit module according to claim 14, wherein the graphics mode includes a table characterizing a number of available colors versus a screen resolution in horizontal pixels per screen by vertical pixels per screen.

19. A circuit module according to claim 14, wherein the video processing circuit includes memory to store a set of predefined video graphics mode characteristics, and wherein the video processing circuit further divides the red, green and blue analog video signals into one or more video screen segment parts and compares the video screen segment parts to the stored predefined video graphics mode characteristics.

20. A circuit module according to claim 19, wherein the video processing circuit includes a video checksum manager for storing and managing checksums associated with each video screen segment part.

21. A computer having a virtual path communication link with a remote computer over a network medium, comprising:

a remote access engine;

a data bus;

a set of circuit modules in communication with a set of corresponding host computers to receive analog video signals from the corresponding host computers, to digitize the analog video signals, to synchronize the video signals to a video display characteristic of the remote computer, and to present the digitized and synchronized video signals to the data bus;

a communication port establishing a connection with the network medium, the remote access engine receiving the digitized and synchronized video signals from a selected one of said set of circuit modules and delivering the selected digitized video signals to the remote computer for display.

22. A computer according to claim 21, wherein:

each circuit module includes;

a main CPU to coordinate a digital to analog conversion of host video signals from a corresponding host computer;

a field programmable gate array, in communication with the main CPU;

a video interface circuit, in communication with the field programmable gate array, to capture the host video signals for the main CPU and field programmable gate array;

a video RAM to store host video signals digitized by the main CPU and field programmable gate array, and to deliver the digitized video signals to the remote access engine for delivery to the remote computer, the video RAM in communication with the field programmable gate array to receive at least video sync processing from the field programmable gate array;

at least one of a mouse driver circuit and a keyboard driver circuit, in communication with the main CPU, to receive, respectively, mouse and keyboard information from the remote computer;

a bus controller, in communication with the field programmable gate array, to communicate information identifying the digitized host video signals and the mouse and keyboard information to the remote access engine.

23. A remote access device to remotely control a host computer and to receive at a remote location a video signal from the host computer, comprising:

a remote access engine between the host computer and the remote location to coordinate delivery of data packets along a telecommunications link between the host computer and the remote location; and

a remote access controller, including a remote access control card communicating with the telecommunications link, to read a present caller ID associated with the remote location, to store a list of predefined caller IDs, to compare the present caller ID with the list and to disable the remote access engine whenever the present caller ID fails to match any from the list of predefined caller IDs.

24. A remote access device according to claim 23, wherein the remote access controller further includes a telephone jack to automatically issue a page alert to a predefined telephone number whenever the present caller ID fails to match any from the list of predefined caller IDs.

25. A remote access device according to claim 23, wherein the remote access controller further resets the host computer wherever the predefined caller ID matches the present caller ID.

26. A remote access device according to claim 23, wherein the remote access controller further reboots the host computer wherever the predefined caller ID matches the present caller ID.

27. A remote access device according to claim 23, further including an external modem and a control module providing AC power to the host computer, the external modem communicating with the control module and automatically answering calls received by the external modem on a different telecommunications link, said control module temporarily interrupting power to the host computer whenever said external modem automatically answers a call.

28. A computer circuit coupled to a data bus and communicating with a Host PC, comprising:

a video input buffering circuit receiving RGB video signals from the Host PC;

an analog to digital converter circuit coupled to the video input buffering circuit to receive and digitize the RGB video signals;

a main gate array circuit to receive the digitized RGB video signals from the analog to digital converter circuit;

a video memory circuit to store the digitized RGB video signals;

a second gate array circuit coupled to the main gate array circuit, the second gate array circuit bridging data between the main gate array circuit and the data bus;

a system clock circuit providing clock signals to the main and second gate array circuits;

a main cpu, communicating with the main and second gate array circuits to direct data between the video memory circuit and the second gate array circuit, the main gate array also controlling data traffic between the analog to digital converter circuit, the video memory circuit, and the main cpu;

a keyboard cpu in communication with the main cpu and at least one of an external keyboard and an external mouse; and

a pixel clock generator to provide a pixel clock signal to the analog to digital converter circuit, the pixel clock generator reproducing in frequency and phase a host pixel clock signal used by the Host PC to produce the RGB video signals received by the video input buffering circuit.

29. A computer circuit according to claim 28, wherein the video memory is a combination of interleaved video RAMs.

30. A computer circuit according to claim 28, wherein the video input buffering circuit includes operational amplifiers, one for each R, G, and B component of the RGB video signal.

31. A computer circuit according to claim 28, wherein the main gate array circuit includes a checksum section to determine a checksum difference between two video frames of the RGB video signal.

32. A computer circuit according to claim 28, wherein the main gate array circuit includes a checksum section to determine a checksum difference between two video frames of the RGB video signal and delivers the checksum difference to the second gate array circuit.

33. A computer circuit according to claim 28, wherein the video memory circuit includes a video RAM and a palette RAM, the main gate array circuit including a checksum section to derive a checksum difference between video frame information in the video RAM versus the palette RAM.

34. A computer circuit according to claim 28, wherein the second gate array circuit includes a timing and control section.

35. A computer circuit according to claim 28, wherein the second gate array circuit includes a video format decoding section.

36. A computer circuit according to claim 28, wherein the second gate array circuit including a video latch area.

37. A computer circuit according to claim 28, wherein the pixel clock generator includes a phase locked loop.

38. A computer circuit according to claim 28, wherein the second gate array circuit includes a video format decoding section generating a vertical blanking period signal and the pixel clock generator includes a sample and hold circuit receiving the vertical blanking period signal at a hold input of said sample and hold circuit, said sample and hold circuit having a hold period greater than a maximum vertical blanking period.

39. A computer circuit according to claim 28, further including:

an ID switch to uniquely identify the circuit communicating with the Host PC in comparison to other circuits communicating with other Host PCs via the data bus.

40. A circuit for communicating RGB video information from a Host computer to a remote computer via a network link, comprising:

video input circuitry to receive the RGB video information from the Host computer;

video processing circuitry to digitize the RGB video information and to decode a video format of the RGB video information received by the video input circuitry; and

a flash palette converter circuit, including;

an address mux receiving the digitized RGB video information as a stream of digital RGB pixel data;

a flash palette converter RAM being addressed by the stream of digital RGB pixel data and outputting for each RGB pixel a palette index byte corresponding to a color value of said RGB pixel.

41. A circuit according to claim 40, further including a pixel assembly circuit to condense a number of palette index bytes into a single assembled pixel byte for storage, including:

a logic array receiving the video format of the RGB video information from the video processing circuitry and receiving the palette index byte from the flash palette converter circuit; and

a set of flip-flops controlled by the logic array to assemble the number of palette index bytes as a function of a characteristic of the video format of the RGB video information.

42. A remote access PC to facilitate communications between a host computer and a remote computer distantly located relative to each other, comprising:

a remote access process to establish a logical data path between the host computer and the remote computer, upon remote user initiation the remote access process receiving a reboot signal from the remote computer on the logical data path;

a control module having an AC power input to receive AC power from an external power source, an AC power output to deliver the AC power from the external power source to the host computer, a switch therebetween, and a control data input to receive the reboot signal and thereupon interrupt AC power to the host computer by operation of the switch.

43. A remote access PC to facilitate communications between a host computer and a remote computer distantly located relative to each other, comprising:

a remote access process to establish a logical data path between the host computer and the remote computer;

a control module having an AC power input to receive AC power from an external power source, an AC power output to deliver the AC power from the external power source to the host computer, a switch therebetween, and a control data input to receive a reboot signal and thereupon interrupt AC power to the host computer by operation of the switch;

a communication circuit establishing a different logical data path between the remote computer and the communication circuit, the communication circuit delivering the reboot signal to the control module when commanded to do so by the remote computer via the different logical data path.

44. A remote access PC according to claim 43, wherein the communication circuit is a modem.

45. A system for coordinating communications between a remote computer and a controlled device, comprising:

a first control module to receive AC power from an external power source, to deliver the AC power from the external power source to the controlled device, the first control module including a switch therebetween to interrupt AC power to the controlled device by operation of the switch;

a communication circuit establishing a logical data path between the remote computer and the first control module, the communication circuit delivering an instruction from the remote computer to the first control module via the logical data path to interrupt AC power to the controlled device by operation of the switch.

46. A system according to claim 45, further comprising:

a management PC communicating with the first control module to deliver an interrupt signal to the first control module whenever the remote computer delivers an interrupt instruction to the management PC via a different logical data path;

47. A system according to claim 45, further comprising:

a second control module daisy-chained to the first control module to receive AC power from the external power source, to deliver the AC power from the external power source to a second controlled device, the second control module including a second switch therebetween to interrupt AC power to the second controlled device by operation of the second switch;

the communication circuit establishing a logical data path between the remote computer and the second control module, and delivering an instruction from the remote computer to the second control module via the logical data path to interrupt AC power to the second controlled device by operation of the second switch.

48. A remote access device for communicating real time video signals from a host PC to a remote PC and for communicating mouse signals entered in response to the real time video signals from the remote PC to the host PC, comprising:

a video process to capture and digitize the video signals from the host PC including video signals indicating a position of a mouse pointer on a monitor associated with the host PC, the position of said mouse pointer identified by the video process being delayed by a period associated with the capturing and digitizing steps;

a mouse synchronizer to capture a current mouse position of the mouse pointer on the monitor associated with the remote PC;

a video application to communicate the current mouse position of the mouse pointer on the monitor associated with the remote PC to the host PC whereupon the host PC jumps the host mouse pointer to a position coincident with the current mouse position.

49. A remote access device according to claim 48, wherein the current mouse position is communicated from the remote computer to the mouse synchronizer in the form of current X/Y coordinates of the remote computer mouse pointer.

50. A remote access device according to claim 48, wherein the mouse synchronizer captures the current mouse position of the mouse pointer on the monitor associated with the remote PC whenever a remote user clicks a mouse button.

51. A remote access interface between a remote workstation having an associated remote monitor and a host device having an associated host monitor, comprising:

a host mouse;

a video capture circuit to intercept analog video signals from the host device and applying the analog video signals to the host monitor such that the host monitor displays a host pointer associated with the host mouse;

a mouse capture circuit to capture remote mouse signals from the remote workstation over a telecommunication path and to transmit the remote mouse signals to the host device for farther processing as though the remote mouse signals were received from the host mouse;

a mouse adjustment process to cause the host pointer on the host monitor to jump to a position determined by the remote mouse signals.