Patent Description:
A KVM switch is a device that typically enables a single user to operate multiple computers (hosts) from a single set of peripheral devices. In some cases, where some of the hosts are more data sensitive than others, it may be recommended to prevent data leakage between host computers connected to KVM switches and between one or more networks connected to the host computers. KVM switches that can maintain separation and/or isolation of data between host computers and/or data flowing through various elements of the KVM switch are usually called secured KVM switches. A KVM switching system according to the preamble portion of claim <NUM>, a keyboard according to the preamble portion of claim <NUM> and a KVM switch according to the preamble of claim <NUM> are known from <CIT> and <CIT>.

One of the weakest links regarding security in KVM switches, in general, and in secure KVM switches, particularly, may be the user awareness of the host that the user is working on. It is important that the user is aware of the type of host the user is working on (e.g., which host is active), to, for example, avoid mistakenly working on an erroneous wrong host. For example, a KVM switch can be connected to three host computer, host A, host B, and host C. The user of the KVM switch may operate the computer as if it is working on host A, when in reality the KVM switch is connected such that host B is active. In this manner, errors can occur. Accordingly, the present invention aims at improving cyber security when using KVM switches.

This technical problem is solved by a KVM switching system according to claim <NUM>, a keyboard according to claim <NUM>, a method according to claim <NUM>, and KVM switch according to claim <NUM>.

In the drawings:.

In other instances, well-known methods, procedures, and components, modules, units and/or circuits have not been described in detail so as not to obscure the invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated.

Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "processing", "computing", "calculating", "determining", "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non-transitory storage medium that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms "plurality" and "a plurality" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "a plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term set when used herein may include one or more items. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof may occur or be performed simultaneously, at the same point in time, or concurrently.

The present invention, in some embodiments thereof, relates to Keyboard, Video and Mouse (KVM) switching systems and, more particularly, but not exclusively, to indication of the selected/active host by a KVM switch. In some embodiments, a KVM switch is a device that enables a single user to operate multiple computers (e.g., hosts) from a single set of peripheral devices. In some embodiments, where at least some of the hosts are more data sensitive than others, it can be important to prevent data leakage between the host computers connected (e.g., directly connected via wired connections) to the KVM switch and between the networks coupled to the respective hosts. KVM switches that maintain data separation (e.g., data isolation) can be referred to as a secured KVM switch. One difficulty regarding security in KVM switches, in general, and in secure KVM switches, in specific, is the user's awareness of the particular host of a plurality of hosts the user is currently working with. It may be important that the user is aware of the active/selected host he works with. In some embodiments, the current invention addresses this issue.

In various embodiments, the KVM switch, the host computers, the peripheral devices and/or any components/devices of the system are connected electrically, mechanically or both. In various embodiments, the KVM switch, the host computers, the peripheral devices and/or any components/devices of the system are connected directly without any intermediary components or devices. In various embodiments, the KVM switch, the host computers, the peripheral devices and/or any components/devices of the system are connected via cables, connectors, wires, PCB traces, pins, switches and/or any other low ohmic resistance element that is used to establish galvanic connection between the components and/or devices.

In various embodiments, the KVM switch, the host computers, the peripheral devices and/or any components/devices of the system are connected through one or more passive or active intermediary components or devices.

In various embodiments, the KVM switch, the host computers, the peripheral devices and/or any components/devices of the system are arranged to cooperate with one another to provide a one or more desired functions.

According to some embodiments, a keyboard-video-mouse (KVM) switching system is provided to identify a selected or active host by a KVM switch. In some embodiments, the user switches between hosts by pressing keys that are located either on the KVM switch enclosure itself or, in the case where the KVM switch is not located close enough to the user, in a remote control of the KVM switch located near the user. The remote control can be referred to as Auxiliary Front Panel (AFP). Once the user switches to a particular host, that host can become an active host.

A host computer, on which the user desires to be the active host, may be selected by pressing on a key on the KVM switch or the KVM switch remote control. In a two hosts KVM switch system (e.g., a system that allows the user to be working on two computers with the same peripheral devices), two keys may be used by the user (e.g., two keys on the KVM switch or two keys on the KVM switch remote control) in order to switch between the two computers. Similarly, in a four hosts KVM switch system, four keys may be used by the user to switch between the four computers. In some embodiments, illumination indicators are associated with the keys, to, for example, drive the user's awareness to an active host. The indictors may be located in, on, in proximity to, or adjacent to one or more keys (e.g., the host selection keys). For example, assume there are three hosts and three keys on the KVM switch (or KVM switch with remote control), and host #<NUM> is the active host, the illuminated indicator illuminates the corresponding push button key #<NUM> or the corresponding indicator #<NUM> is illuminated. In some embodiments, a remote control of the KVM switch having the indicators may be configured to be located on top of a computer display frame to, for example, provide an improved line of sight view between a user's eyes and an indication of the active host.

In some embodiments, the KVM switch enclosure or the remote-control enclosure may include one or two digits display that displays the host number, e.g., the digit '<NUM>' continuing with the above example, as the indicator. To ease the switching between hosts, some KVM switch may support selection of the active host using key-press combinations, also known as keys shortcuts, over the keyboard. For example, pressing 'Ctrl' + 'Alt' + '<NUM>' keys on the keyboard may switch an active host to host #<NUM>, and pressing 'Ctrl' + 'Alt' + '<NUM>' may switch active host to host #<NUM>.

For purposes of better understanding some embodiments of the present invention, as illustrated in <FIG> of the drawings, reference is first made to <FIG>.

<FIG> schematically illustrates a typical system configuration with a KVM switch. A system <NUM> includes a keyboard <NUM>, a mouse <NUM>, a display <NUM> (also known as a computer monitor), a KVM switch <NUM>, a plurality of computer hosts <NUM>, and in some embodiments a KVM remote control <NUM>.

According to some embodiments, the system may further include speakers, headphone, microphone, printers and/or other peripheral devices such as external storage, card reader, such as smart card reader for authentication, etc. (not shown in <FIG>). Hosts <NUM> of system <NUM> may be coupled to local area networks (LANs) or any other communication networks. The network coupled to each host may be of a different security level. For example, one network is an unclassified network that is connected to the Internet, while the other network is a classified network and is only internal in an organization or a campus.

The hosts <NUM> may be electrically and/or mechanically coupled to the LANs and/or any other communication networks. The hosts <NUM> may be directly connected or coupled to one or more of the LANs and/or one or more of any other communication networks without any other devices in between. In various embodiments, the connections are through cables, electrical connectors, wires, PCB traces, pins, switches, and/or any other low ohmic resistance element that is used to establish galvanic connection between elements.

According to some embodiments, the KVM switch <NUM> is configured to couple to keyboard <NUM> and/or mouse <NUM> and/or display <NUM>, and allows the user to control multiple computers (or hosts) <NUM> from a single set of peripherals, such as, keyboard <NUM>, video monitors <NUM>, and mice <NUM>. In some embodiments, the KVM switch <NUM> allows switching two or more video monitors <NUM> and/or three or more user interface devices (e.g., in USB standard as Human Interface Devices (HID)) as well as audio peripherals, such as, speaker and microphone, other USB devices, such as, ID card readers, and/or other devices as are known in the art to couple to and be switched by a KVM switch.

In order to switch between hosts <NUM>, the user may press a dedicated push button located on the enclosure of KVM switch <NUM>. Upon receiving and/or processing of the host switching command, the corresponding indicator in KVM switch <NUM> may be illuminated. The number of computers or hosts <NUM> that can be coupled to the KVM switch may be two, as illustrated in <FIG>. In some embodiments the hosts themselves may reside in remote locations, such as, in data centers.

In some embodiments, KVM switch <NUM> may be located out of reach of the user. For example, the KVM switch <NUM> may be few meters away from the user's desk in the other side of the room or up-to many kilometers away in different premises. In such cases, a distance extender device, coupled between the user peripherals <NUM>, <NUM>, <NUM> and the KVM switch <NUM>, may be used. The distance extender's media may include a USB cable, a category <NUM> cable that can carry Ethernet family protocols, an optical fiber or the like.

In some embodiments, a remote control can be used to switch between hosts. For example, when the user cannot reach, or cannot easily reach, the KVM switch <NUM> push button keys on the KVM switch enclosure, a remote control <NUM> may be used. To switch between hosts <NUM>, the user may press a push button located on the enclosure of remote control <NUM>. Upon receiving a switching command by remote control <NUM>, remote control <NUM> sends the switching request command to KVM switch <NUM>. After processing this command by KVM switch <NUM>, KVM switch <NUM> may send back a switching acknowledge to KVM remote control <NUM> and then KVM remote control <NUM> illuminates the proper indicator.

In some embodiments, securing the KVM system from cyber-attacks is desired. The secure KVM may have several levels of security. One level includes a "whitelist" or authorized peripheral devices that are allowed to be coupled to KVM switch <NUM>. Another level is to enforce only unidirectional communication to further isolate between the hosts so that no data (or substantially no data) can be leaked between the hosts. In some embodiments, data from the HID device may only flow to the host and for the video stream, data may only flow from the host to the display. In some embodiments, EDID reading or USB device enumerations may be used for bi-directional communication that is needed in the initialization setup. This bi-directional communication may be made secured by allowing it only in KVM power-up and using a host emulator and/or peripheral device emulators in order to communicate this data between the peripheral devices and the host whenever it is needed.

Reference is made now to <FIG> illustrates a standard QWERTY keyboard <NUM> including alphanumeric keys <NUM>, control keys <NUM>, function keys <NUM>, navigation keys <NUM>, and numeric keypad <NUM>. The keyboard <NUM> may also include three illuminated indicators <NUM> to indicate locked states that can be activated by the three lock keys: Caps Lock, Num Lock and Scroll Lock. The Caps Lock key is used for entering capital letters, the Num Lock key is used to switch between digits and the navigation keys in the numeric keypad, and Scroll Lock key originally used together with the arrow keys to either scroll the contents of a text window or to moving the cursor on the text window.

In some embodiments, the "KVM switch" includes a device that switches, e.g., couples, between a plurality of host computers and at least one set of peripheral devices. In various embodiments, the set of peripheral devices may include a single peripheral device (e.g., a mouse) or a plurality of peripheral devices provided as a set (e.g., a keyboard and a mouse). The set of peripheral devices may include of at least one of a keyboard (K) and a mouse (M). In various embodiments, the mouse is a track ball, touch pad or the like. In some embodiments, the set of peripheral devices may further include a video display (V). The video display, also referred as the computer monitor, may be any device presenting visual information to the user, including, but not limited to, cathode-ray tube CRT display, Plasma Display, Liquid Crystal Display (LCD), Light-Emitting Diode (LED) display and the like. The computer monitor may come in apparatus form-factor of computer monitor, TV set, head-mounted display, video projector and the like.

In some embodiments, the set of peripheral devices includes a plurality, e.g., two or four, computer monitors. The set of peripheral devices may further include at least one of, or any combination of, audio devices such as speaker or headset to enable hearing voices or sounds transmitted from the host computer, a microphone to enable transmission of voice from the user to the host computer, an IP telephone handset to perform telephone calls through the host computer network, a video camera to perform video tele-conferencing, a user authentication device, such as, fingerprint reader, biometric reader, token generator reader, Common Access Card (CAC) reader, Personal Identity Verification (PIV) card reader, smartcard reader and the like. The set of peripheral devices may further include other personal use peripheral devices such as personal printers, personal scanners, personal USB devices and the like.

In some embodiments, peripheral devices switch is the switch positioned between the one or more peripheral devices and the plurality of hosts, for instance as an alternative to the KVM switch. In some embodiments, the peripheral devices switch switches between peripheral devices such as Keyboard, Video monitor and Mouse peripheral devices as well as all other devices mentioned above, such as microphone, smartcard readers and the like. In some embodiments, the peripheral devices switch includes a KVM switch as well as a KM (Keyboard and Mouse only) switch, a KVM (video) combiner, a USB devices switch, an audio devices switch, or any similar device that switches. In some embodiments, the peripheral devices switch is coupled to a set of one or more peripherals and a plurality of hosts. In some embodiments, the peripheral devices switch is coupled between a set of one or more peripherals and a plurality of hosts. In some embodiments, the peripheral devices switch includes both a KVM switch and a KVM matrix, or peripheral devices matrix, which means a device that may switch, coupled between multiple sets of peripheral devices and multiple host computers in a way that a plurality of users may work simultaneously with a plurality of host computers wherein no two users are simultaneously operating with the same host computer.

According to some embodiments, additional feedback is provided by the system to indicate the active host, e.g.,, the current host the user is working with, and the current host the KVM switch is coupled to the set of the peripheral devices operated by the user. In some embodiments, in order to provide additional feedback each of the different hosts coupled to the KVM switch is coded with a distinct color, and providing this color indication, by light illumination by indicators in at least one of or the combination of (a) the KVM switch enclosure and/or the KVM remote control enclosure; and (b) at least one of or any combination of the peripheral devices in the peripheral device set, operated by the user.

Reference is made now to <FIG> is a schematic block diagram that shows a portion of a KVM switch <NUM>. The KVM switch <NUM> includes keys 310a, 310b, 310c and 310d (e.g., push-buttons) that select the active host when pressed (e.g., key 310b corresponds to host #<NUM>). These keys may be located in the front panel of KVM switch <NUM> enclosure. Each key is mechanically coupled to a switch 320a, 320b, 320c and 320d. Switches 320a, 320b, 320c and 320d are coupled respectively to key interfaces 340a, 340b, 340c and 340d. Key interfaces 340a, 340b, 340c and 340d are coupled to a KVM switch controller <NUM> through connection <NUM>. When a key 310a, 310b, 310c or 310d is pressed, KVM switch controller <NUM> may receive this event and change the active host accordingly. For the sake of clarity, all KVM switch <NUM> circuitries of the switch itself and all the circuitries between the set of peripheral devices interface and the host computer interface are not shown in <FIG>.

Each one of the key interfaces 340a, 340b, 340c and 340d is coupled to a polychromatic light source 330a, 330b, 330c and 330d respectively. The polychromatic light source may include one or more RGB LEDs that include illumination from Red LED, Green LED and Blue LED. Additionally, the polychromatic light source may include two or more monochromatic light sources. Upon changing the active host computer, KVM switch controller <NUM> may control, using key interfaces 340a, 340b, 340c and 340d, the polychromatic light sources 330a, 330b, 330c and 330d.

Herein and hereinafter, the suffix 'x' in 330x or 340x or any other reference signs may mean each, any or all similar elements, hence 340x, in this case, means any of 340a, 340b, 340c and 340d.

The key corresponding to the active host computer may be illuminated with the color assigned (or associated) to this host computer, while all other keys illumination is turned off. Additionally or alternatively, KVM switch controller <NUM> may send a command to a remote control via interface <NUM> to set an indication of the current active host in the remote control. The KVM switch controller <NUM> is configured to send a command to set a polychromatic indication of the active host to any one of or any combination of the set of peripheral devices via peripheral devices interface circuitry <NUM>. Peripheral devices interface circuitry <NUM> includes an interface to keyboard <NUM>, in some embodiments, one or more interfaces to a video display <NUM>, interface to a mouse or a pointing device <NUM>, and in some embodiments one or more interfaces to additional peripheral devices such as CAC card reader, microphone, etc..

In some embodiments of the invention, the selection of the active host computer may be initiated by external trigger and not by pressing keys 310a, 310b, 310c and 310d of KVM switch <NUM>. For example, as presented in detail hereinafter, the command for selecting different host computer may be initiated by the remote control or one of the devices in the set of peripheral devices. In such case, KVM switch controller <NUM> may update its own indications by proper illuminating commands to any indication in polychromatic light source 330a, 330b, 330c and 330d and by sending the proper commands, if necessary, to the remote control and the peripheral devices.

Reference is now made to <FIG> is schematic block diagram of a remote control <NUM> of KVM switch <NUM>. The host selection keys and the active host indication may have similar elements to the one presented in KVM switch <NUM> (shown in <FIG>).

The KVM block diagram of a switch remote control <NUM> includes four keys 410a, 410b, 410c and 410d; four switches 420a, 420b, 420c and 420d; four polychromatic light source 430a, 430b, 430c and 430d; and four key interfaces 440a, 440b, 440c and 440d. The key interfaces 440a, 440b, 440c and 440d are coupled to a remote-control controller <NUM> via connection <NUM>.

The number of supported hosts by the KVM switch may be in the range of <NUM>-<NUM>. In some embodiments, the number of supported hosts may be any other natural number, n, and the numbers of keys 410x as well as elements 420x, 430x, 440x may be respectively 'n' too.

Suppose the present active host is host #<NUM>, then remote-control controller <NUM> may command the polychromatic light source 430b to illuminate with the color associated with host computer #<NUM>. Polychromatic light sources 430a, 430c and 430d may be controlled by remote-control controller <NUM> to off-state, e.g., no illumination. When the user presses key 430c, remote-control controller <NUM> receives this event and sends this event via interface <NUM> to KVM switch <NUM>. Interface <NUM> is coupled by a cable to interface <NUM>. Additionally or alternatively, the KVM remote control and KVM switch may be coupled via wireless connection.

The request to switch from host #<NUM> to host number #<NUM> may be processed in KVM switch <NUM> and as a result it produce back to remote control <NUM> command to turn-off the indication of host #<NUM> and command to turn-on the indication of host #<NUM> by illuminating key 410c (by polychromatic light sources 430c) with the color associated with host #<NUM>.

Additionally or alternatively, remote control <NUM> includes an active host indicator <NUM>. Active host indicator <NUM> may include a digit display and background display. The background display may be illuminated with the color assigned to the active host and the digit display displays the digit corresponding to the channel number so with regards to the above example, before the host switch the digit display was displaying the digit '<NUM>', and after the host switch, the digit display displays the digit '<NUM>'. The color of the digit is either black (e.g., illumination off) or illuminated with a color that creates a good contrast to the color assigned to the active host (e.g., to attract the awareness of the user).

The background display and digit display may be a 2D pixel array display wherein the digit and the background are created by manipulating the pixels of the image displayed by the 2D pixel matrix. Additionally or alternatively, digit display may be a seven-segment display and background display is a flat surface illuminates by one or more polychromatic light sources. Active host indicator <NUM> may be controlled by remote-control controller <NUM> in according to the command received from KVM switch <NUM>.

Reference is made now to <FIG> illustrate several variants of keyboards that support a KVM-switch. <FIG> illustrates a keyboard 100a including standard keyboard arrangement <NUM> and additional keyboard section 110a to support a KVM switch. Keyboard section 110a, in some embodiments of the invention, includes four keys <NUM> that to select active host similar to keys 310x of keyboard switch or KVM switch <NUM> and keys 410x of remote control <NUM>. The four keys <NUM> may be labeled by the digits '<NUM>' - '<NUM>'. In addition, keyboard section 110a may include two indicators <NUM> and <NUM>, e.g., LED light sources, that are used to reflect statuses from the KVM switch. The statuses may be the state of the KVM switch such as power on, initial setup in process, error indication, etc. In some embodiments of the invention, the position of keyboard section 110a is in the right side of keyboard <NUM>.

In some embodiments of the invention, each one of keys <NUM> of keyboard 100a is a polychromatic illuminated key. For the sake of clarity in the figure, only the digit '<NUM>' key is illustrated as illuminated key. The internal structure of each illuminated key is illustrated in the figure inside a box above the keyboard near key <NUM>.

Each key may include a plastic cap, coupled to a key switch, and besides or below the key switch, there is polychromatic light source. In some embodiments, the polychromatic light source may include three LEDs, each with a different color: R-RED LED, G-Green LED and B-Blue LED. This LEDs constellation also known as RGB LED. Standard <NUM> bit per color RGB control may provide over <NUM> million possible colors. Additionally or alternatively, other polychromatic light source, such as, a white light sources coupled to RGB filters or the like may be used.

KVM control keys <NUM> may be illuminated by polychromatic light sources as well. When a key <NUM> is pressed, the press event may be sent by the standard keyboard interface or alternatively by a dedicated interface between keyboard section 110a and the KVM switch to the KVM switch. When an acknowledge is received (the KVM can be switched to the host associated with this key and this host can become the active host), the key <NUM> illuminates in a preset color that is associated with the current active host.

In some embodiments, in order to provide the full attention of the user to the fact that it currently coupled to this specific host, all other keys of keyboard 100a are illuminated with the same color. In some embodiments, only some of the keys may be illuminated with this preset color. For example, only the alphanumeric keys <NUM> are illuminated or only control keys <NUM> or function keys <NUM> are illuminated.

<FIG> illustrates a KVM supporting keyboard 100b including an example of a standard keyboard arrangement <NUM> and an additional keyboard section 110b to support a KVM switch. Keyboard section 110b, in some embodiments of the invention, may include four keys <NUM> (keys with the same function as in keyboard section 110a) that select an active host. Keys <NUM> may be labeled by the digits '<NUM>' - '<NUM>'. In addition, keyboard section 110b may include a display <NUM> to indicate the KVM switch status. The statuses may be the state of the KVM switch such as power on, initial setup in process, error indication etc. Display <NUM> may indicate the number of the host that is currently active. Display <NUM> may be a seven-segment display. Display <NUM> may have a polychromatic background display that function in similar way as active host indicator <NUM> of remote control <NUM> that has been described hereinabove. In some embodiments of the invention, the position of keyboard section 110b may be in the right side of keyboard <NUM>.

Keyboard 100b may include illuminated function keys <NUM>. Illuminated function keys are similar to function keys <NUM> but includes polychromatic light source under these keys. Due to the location of function keys <NUM> illumination of this keys capture the attention of the users.

As in keyboard 100a, KVM control keys <NUM> may be illuminated by the polychromatic light source as well. Upon selection of the active host in the KVM switch, keys <NUM> and the appropriate key <NUM> are illuminated with the color associated with the active host computer. In some embodiments, display <NUM> displays in the same color. All other keys of keyboard 110b may be either illuminated or not illuminated. In some embodiments of the invention, all other keys of keyboard 110b are illuminated with a natural color, such as, white, yellow or blue to support well known in the art illumination for keyboard operation in dark condition. In some embodiments, these keys may be illuminated for a use in specific application. For example, some application may illuminate one or more letter keys to indicate their specific use in the application.

<FIG> illustrates yet another KVM supporting keyboard 100c including standard keyboard arrangement <NUM> and additional keyboard section 110c to support a KVM switch. In some embodiments of the invention, the position of keyboard section 110c is in the top side of keyboard <NUM>. In addition to the keyboard section 110c, keyboard 100c in the same top row may include multimedia extension keyboard section <NUM>. The keyboard section <NUM> may include keys such as pause, paly, fast forward, volume keys and a like. Alternatively, other keyboard extensions section or keys, e.g., such as gaming keyboard extension, may be integrated to keyboard 100c (or 100a, 100b). Keyboard section 110c in some embodiments of the invention, includes eight keys <NUM>. Keys <NUM> are configured to select one active host out of <NUM> possible hosts coupled to the KVM switch. Keys <NUM> here, may function similar to keys <NUM> in sections keyboards 110a, 100b and keys 310x and 410x in the KVM switch and the remote control respectively. Keys <NUM> of keyboard section 110c may be labeled by the digits '<NUM>' - '<NUM>'. In addition, two indicators <NUM> and <NUM>, similar to the ones in keyboard 100a, may be used to reflect statuses from the KVM switch.

Keyboard 100c includes an illuminated space key <NUM>. Illuminated space key <NUM> includes polychromatic light source under the key. Due to the location of space key <NUM>, illumination of the space key may capture the attention of the user. As in keyboard 100a, KVM switch control keys <NUM> may be illuminated by the polychromatic light source as well. Upon selection of the active host in the KVM switch, key <NUM> and the appropriate key <NUM> in keyboard section 110c may be illuminated with the color associated with the active host computer. All other keys of keyboard 110c may be either illuminated or non-illuminated keys.

In some embodiments of the invention, those keys may be illuminated with a natural color, such as, white, yellow or blue to support well known in the art illumination for keyboard operation in dark condition. In some embodiments, those keys may be illuminated for a use in specific application.

Reference is made now to <FIG> is a schematic block diagram of a general peripheral device coupled to a KVM switch and supporting polychromatic indication in accordance with some embodiments of the present invention. A peripheral device <NUM> is coupled to a KVM switch <NUM> through interface <NUM> of KVM Switch <NUM> and interface <NUM> of peripheral device <NUM>. Peripheral device may be any peripheral device including mouse, keyboard, microphone or any other peripheral devices mentioned hereinabove. The specific circuitry of each peripheral device is indicated by circuitry <NUM>.

Circuitry <NUM> is controlled by controller <NUM>. Controller <NUM> is coupled to interface <NUM> to receive command and communication from the active host through KVM switch <NUM>, and to send peripheral device data to the active host through KVM switch <NUM>. Peripheral device <NUM> further includes polychromatic indication <NUM> to illuminate in the color associated with the active host.

Additionally or alternatively, peripheral device <NUM> may be coupled using interface <NUM> to interface <NUM> of KVM switch <NUM>. This connection may be used as a secondary communication channel dedicated to the polychromatic indication functionality. In some embodiments, the controller <NUM> may be used to control polychromatic indication <NUM> and to communicate with KVM switch <NUM> in this case.

In some embodiments of the invention, peripheral device <NUM> is a mouse and polychromatic indication <NUM> illuminates the mouse and/or the surface area around the mouse.

In some embodiments of the invention, peripheral device <NUM> is a microphone and the polychromatic indication <NUM> illuminates the microphone head whenever the microphone audio is open to the active host with the appropriate color (e.g., the indication is only active when the microphone is open for transmitting audio signals, for example, conditioned upon a push to talk button).

In some embodiments of the invention, peripheral device <NUM> is keyboard <NUM> and the polychromatic indication <NUM> illuminates one or more keys of keyboard <NUM> with the appropriate color.

In some embodiments of the invention, peripheral device <NUM> is smartcard reader and the polychromatic indication <NUM> illuminates the doorway into which the smartcard is inserted with the appropriate color.

In some embodiments, the KVM switch <NUM> may support some peripheral devices to be coupled to different host then the main KVM switch. For example, if an application in one host computer, e.g., host #<NUM>, needs the smartcard reader coupled to host #<NUM> for the full process while the user wants during this time to switch and work with host #<NUM>, some KVM switch can allow this kind of operation. If host # <NUM> is assigned to the red color and host #<NUM> to the blue color. According some embodiments, the KVM switch may control the peripheral devices to illuminate in red, while the smartcard reader is controlled to illuminate in blue.

In some embodiments, the control command to illuminate in polychromatic light source by the KVM switch <NUM> is performed by transfer of a data sequence including <NUM>-bit color data (<NUM>-bit R, <NUM>-bit G and <NUM>-bit G) each time an active channel is changed. Additionally or alternatively, KVM switch <NUM> may send the color assignment for the hosts from time to time (for example after reset and when color assignment is changed) and each device that has color illumination capability may set the appropriate color based on the stored color table data stored in the device's memory. The setup of colors assignment to the KVM switch may be performed in several ways.

First, a default setup may be stored in the KVM switch during manufacturing. After deployment the setup may be changed using setup session open with one of the host or setup session perform by a system administrator using an external laptop coupled to special setup interface in KVM switch <NUM>. Yet setup may be done using the key shortcuts with the keyboard. For example, the key sequence 'Ctrl' + 'Shift' + '<NUM>' followed by six hexadecimal digit key sequence may be used to associate host #<NUM> with the color determined by <NUM> bit (two hexadecimal digits) for the red component, <NUM> bit for the green component and <NUM> bit for the blue component. For example, typing Ctrl + Shift + <NUM>, "<NUM>" may assign a purple color, RGB (<NUM>, <NUM>, <NUM>), to host #<NUM> of the KVM switch.

Reference is made now to <FIG> is a flow chart of a method for that can be executed by the KVM switch controller according to some embodiments of the present invention. In step <NUM> the controller stores for each host port of the KVM switch a color. The color may be assigned through several methods. A default assignment of colors to the hosts may be made in the factory. For example, a two-hosts KVM switch may be pre-set to a setup where host #<NUM> assigned with green color and host #<NUM> assigned with red color.

Additionally or alternatively, the setup can be changed dynamically during operation using a configuration port in the KVM switch. For example, a system administrator may couple his laptop to a special configuration interface or, for example, to the mouse USB port of the KVM switch, open a terminal connection, and in this special setup session, among other tasks, sets the color of each host in the system. Yet another option for the color-host assignment of the KVM switch, may be to set using a software running on one of the hosts in any time by the user. Color assignment may also be performed by typing key sequence from the keyboard (e.g., keyboard shortcuts).

In step <NUM>, the KVM switch controller waits for a request to change the active host from the user. The request event may come from several sources: key press in any device in the KVM system that have switching host keys such as 310x, 410x <NUM>, and/or other switching host keys as are known in the art; keyboard and/or mouse shortcuts; and/or a mouse movement that crosses display boundaries in a single virtual display that includes several physical displays that can be driven from several hosts. After receiving the request to change the active host, in step <NUM>, the KVM switch controller may perform the actual switching or the routing of the peripheral device to the new active host. Step <NUM>-<NUM> can include receiving from the user, a switching command, selecting an active host accordingly, and coupling the active host to the user's set of peripheral devices.

Next, in step <NUM> the KVM switch controller fetches the color assigned to the new active host and in step <NUM> the KVM switch controller updates the indicators to the user by sending an instruction to all indicators that indicates the active host to the user. Steps <NUM> and <NUM> indicate the active host to the user by illuminating in the color assigned to the active host computer. The indicators are on the keyboard or any other peripheral device coupled to the KVM switch. For all polychromatic indication the KVM switch may send with the instruction the color to be illuminated.

The communication between the KVM switch and the external indicators may be performed using a dedicated connection or an existing connection. For example, the connection with the remote control may be performed using RS232. The communication with a peripheral device may be performed using USB where the indicator is implemented as independent USB device in multidevice USB device were the other device is the HID device.

The user awareness is increased for the host as he works with in a multi host environment and/or multi network environment and/or with multi security levels environment. Security breach by the user is prevented due to the association built in the user's mind between the color of the host and/or network and the security rules apply in each host and/or network. In some embodiments, the indication system includes a subsystem to ensure the color indication system is working properly. This may be performed by measuring the current consumption of each monochromatic light source in this subsystem and if the current consumption is not as expected, e.g., indication of a failure in the light source, the system may alert the user or the administrator or disable the indication system. Additionally or alternatively, a sensor based failure detection system may be used.

In some embodiments of the invention, a peripheral devices switching system configured to be coupled to a plurality of host computers includes: at least one set of peripheral devices; a peripheral devices switch, e.g., KVM switch <NUM>, and one or more polychromatic light sources. The peripheral devices switch <NUM> is configured to be coupled to said at least one set of peripheral devices and said plurality of host computers, where the peripheral devices switch assigns a color to each host computer of the plurality of host computers, and the peripheral devices switch <NUM> couples between said at least one set of peripheral devices and an active host computer of the plurality of host computers. The one or more polychromatic light sources are included in the peripheral devices switch, the at least one of the peripheral devices of the sets of peripheral devices or both. The peripheral devices switch <NUM> indicates the active host computer by, for example, illuminating at least one of or a combination of the light sources by the color that is assigned to the active host computer.

Reference is made now to <FIG> is an illustration view of a set of multimedia peripheral devices <NUM> coupled to a KVM switch <NUM> and supporting polychromatic indication in accordance with some embodiments of the present invention. The set of multimedia peripheral devices <NUM> comprises of left speaker <NUM>, right speaker <NUM>, microphone <NUM>, and camera <NUM>. Left speaker <NUM>, right speaker <NUM>, microphone <NUM>, and camera <NUM> are all connected to KVM switch <NUM> (for clarity these connections are not shown in the illustration). The peripheral may use interfaces similar to interfaces <NUM> and <NUM> described hereinabove. Speakers <NUM> and <NUM> receive through the interfaces a stereo audio stream to be played by the speaker. Audio stream may be in digital format or analog format. In addition, speakers <NUM> and <NUM> receive from the KVM switch <NUM> commands to illuminate polychromatic indicators <NUM>, <NUM>, <NUM>, <NUM>. polychromatic indicator <NUM> is illuminate in the color associated with the active host whenever the speaker is connected to the active host. Polychromatic indicator <NUM> is illuminate in the color associated with the active host whenever an active signal is transmitted to the speaker. In an exemplary embodiment of the invention, only polychromatic indicator <NUM> or polychromatic indicator <NUM> is provided. Alternatively, indicator <NUM> or indicator <NUM> may be monochromatic indication while the other indication is polychromatic indication. In an exemplary embodiment of the invention, Polychromatic indicator <NUM> illuminates the area around the polychromatic indicator <NUM> which provide a native illustration for the speaker activity. Polychromatic indicator <NUM> and <NUM> act in similar way as Polychromatic indicator <NUM> and <NUM>.

Microphone <NUM> transmit audio signals captured by the microphone to KVM switch <NUM>. From KVM switch <NUM> the audio signal may be transferred to an active host. Audio stream may be in digital format or analog format. Microphone <NUM> comprises polychromatic indicator <NUM> configured to be illuminate whenever microphone <NUM> is connected to an active host with the color associated with the active host. This indication, <NUM>, only indicate to the user that if the microphone will be opened which host will receive the sensed audio signal of the microphone. To actually open the microphone circuitries to transmit an audio signal, a push to talk button <NUM> is provided. Conditioned upon pressing the push to talk button <NUM>, the microphone transmits the audio signal to KVM switch <NUM>. To indicate that the microphone is open for transmitting audio signals, indication, <NUM> illuminates in the color associated with the active host.

Camera <NUM> transmits video signals captured by the camera to KVM switch <NUM>. From KVM switch <NUM> the video signal may be transferred to an active host. Camera <NUM> comprises polychromatic indicator <NUM> configured to be illuminate whenever camera <NUM> is connected to an active host with the color associated with the active host. This indication, <NUM>, only indicate to the user that if the camera will be opened, which of the hosts will receive the video signal. When the camera transmits the video signal to KVM switch <NUM>, in order to indicate the user that an active video stream is transmitted, indication, <NUM> illuminates in the color associated with the active host.

In an exemplary embodiment of the invention, indicators <NUM> and <NUM> or indicator <NUM> and <NUM> are collocated with indicator <NUM> or indicator <NUM> are surrounding indicator <NUM> or indicator <NUM> respectively. In an exemplary embodiment of the invention, only polychromatic indicator <NUM> or polychromatic indicator <NUM> is provided. Alternatively, indicator <NUM> or indicator <NUM> may be monochromatic indication while the other indication is polychromatic indication. In an exemplary embodiment of the invention, only polychromatic indicator <NUM> or polychromatic indicator <NUM> is provided. Alternatively, indicator <NUM> or indicator <NUM> may be monochromatic indication while the other indication is polychromatic indication.

Reference is made now to <FIG> is an illustration view of an external disk device <NUM> coupled to a KVM switch <NUM> and supporting polychromatic indication in accordance with some embodiments of the present invention. External disk device <NUM> is connected to KVM switch <NUM> using USB connector <NUM>. External disk device <NUM> comprises polychromatic indicator <NUM>. In prior art external disk devices, the indication is used to indicate whenever there is an active read or write transaction with device <NUM>. According to the present invention, whenever there is an active read or write transaction with device <NUM> polychromatic indicator <NUM> is illuminate in the color associated with the active host. The USB bus is used both to transfer the read/write data for the disk as well as the polychromatic illumination command. In an exemplary embodiment of the invention, composite device USB interface is used and the disk is one USB device that communicate with the active host while the polychromatic indicator has a controller which is another USB device and both devices share the same USB bus.

Reference is made now to <FIG> is an illustration view of a multi-domain smart-card reader <NUM> coupled to a plurality of hosts <NUM> and supporting polychromatic indication in accordance with some embodiments of the present invention. Multi-domain smart-card reader <NUM> is a card reader that is configured to accept smart-card <NUM> that is used to identify and authenticate a user to a plurality of hosts <NUM>. Multi-domain smart-card reader <NUM> may be connected to KVM switch <NUM> that provide the coupling to the plurality of hosts <NUM> or may integrate the KVM switch (i.e., the card reader peripheral switch) inside the multi-domain smart-card reader <NUM> enclosure. Upon entering card <NUM> to multi-domain smart-card reader <NUM> card slot the user may authenticate himself in front of one of the hosts that supported by the multi-domain smart-card reader <NUM> (in this exemplary embodiment four hosts are supported). To authenticate to each of the hosts <NUM>, the user needs to press one of the push-buttons <NUM>. Upon successful authentication the corresponding indicator <NUM> will illuminate in the color associated with the authenticating host. Multi-domain smart-card reader <NUM> may keep coupling with a single card to several host simultaneously. Each one of indicator <NUM> will illuminate in the color associated with the corresponding host. To discard authentication from a specific host, the user may press one of the push-buttons <NUM> again. The corresponding indicator <NUM> will turn off. Upon removing smart-card <NUM> from multi-domain smart-card reader <NUM>, all authentication with the host will be discarded.

Reference is made now to <FIG> is an illustration of another keyboard 100d with KVM switch support. As in previous embodiment of such a keyboard 100a, 100b and 100c there are additions keys and indicators to the standard keyboard including four KVM control keys <NUM> that are configured to select active host <NUM>, KVM control key <NUM> that is special KVM function key, and indicators 114d and 116d that are used to indicate special peripheral status of devices connected to the KVM switch that is connected to keyboard 110d. Key <NUM> may be used to extend the selection of the active hosts from four to eight in the following way. For selecting hosts #<NUM> to host #<NUM> the user presses on one of keys <NUM>. The digit <NUM> - <NUM> over the upper left side of keys <NUM> cap is illuminated with the color assigned to the corresponding host computer. For selecting hosts #<NUM> to host #<NUM> the user presses on key <NUM> and then on one of keys key <NUM>. The digit <NUM> - <NUM> over the lower right side of keys <NUM> cap is illuminated with the color assigned to the corresponding host computer <NUM>. Other functions may be assigned to key <NUM> by sequences of multiple presses, long press or simultaneous press with other keys.

Indicators 114d and 116d may be used to indicate the connection status of a specific peripheral devices that are connected to the KVM switch. For example, indicator 114d may be used to indicate by illuminating with the color associated with host <NUM> that a card reader is authenticated with and indicator 116d may be used to indicate by illuminating with the color associated with host <NUM> that a speaker is connected to be the KVM switch.

Interface <NUM>, illustrated in the figure by a cable and a connector, is implementing the interface between KVM switch <NUM> and keyboard 100d. As illustrated in <FIG> and the accompanying text in the description, this interface may be split to two different communication interfaces: (<NUM>) a standard communication from the peripheral to the host, and (<NUM>) an additional, extended functionality, communication between the KVM switch <NUM> and keyboard 100d. This additional communication interface may be used to provide security functions to lock indicators <NUM>.

Some secure KVM switches, for example, the ones that are certified to protection security profile of National Information Assurance Partnership (NIAP), blocks the lock keys status commands that are sent by the host in response to lock keys press events and are intent to indicate the lock keys status by lock indicators <NUM>. This blocking is done since sending the lock keys status commands violates the security policy of having the keyboard device a unidirectional device that only transmit data from the keyboard to the hosts. As will be seen next, having two separated interfaces: one for the standard keyboard, and another one for the communication between the KVM switch and the keyboard, provide a solution for relaxation of this lock indication blocking requirement.

In an exemplary embodiment of the invention, interface <NUM> may be USB. Optionally, the USB interface may be composite device comprises two USB devices transferring data on the same USB bus, connectors and cable. Alternatively, interface <NUM> may be two completely separate communication protocols, optionally, running over the same cable and connectors. For example, the keyboard may use USB Type C connector which have standard USB data pin and additional high-speed data pins that can be used out of the standard as the additional extended functionality communication between the KVM switch and the keyboard.

Reference is made now to <FIG> is a block diagram of a keyboard 100d with support of interface separation between the standard keyboard functionality and the KVM switch support functionality in accordance with some embodiment of the present invention. Keyboard 100d is connected to KVM switch <NUM> using interface <NUM> (illustrated in <FIG> too). In an exemplary embodiment of the invention, interface <NUM> is USB communication protocol. In some embodiment, the USB cable and USB connector are of USB <NUM>. X protocol and the connector type is USB type A. Alternatively, USB cable and connector are of USB <NUM>. X protocol and the connector type is USB type C. Additionally or alternatively, other USB protocol and non-USB protocol are used and other type of connectors are used as well. KVM switch <NUM> is connected to a plurality of host <NUM>. Alternatively, Keyboard 100d may be connected directly to host <NUM> as illustrated in dashed lines in <FIG>. Keyboard 100d comprises nine elements: standard keyboard device controller <NUM>, standard keyboard keys <NUM>, keyboard keys illumination elements <NUM>, KVM switch keyboard device controller <NUM>, KVM switch keys <NUM>, KVM switch keys illumination elements <NUM>, composite interface circuitry <NUM>, keyboard composite controller <NUM>, and lock indication illumination elements <NUM>.

When the keyboard is connected directly to host <NUM>, keyboard 100d act as a standard keyboard. Composite interface circuitry <NUM> detect that keyboard 100d is connected directly to host <NUM> so composite interface circuitry <NUM> instructs keyboard composite controller <NUM> to give full control in keys (<NUM>, <NUM>) and illumination elements (<NUM>, <NUM>, <NUM>) to standard keyboard device controller <NUM>. In this mode of operation, the keyboard act as a standard keyboard. Standard keyboard device controller <NUM> can scan keyboard keys <NUM> and upon press, i.e., make or break key events the standard keyboard device controller <NUM> sends the appropriate command to host <NUM> through composite interface circuitry <NUM> and interface <NUM>. Composite interface circuitry <NUM> performs transparent (non-composite) transfer, and interface <NUM> in this case is carrying a single keyboard device interface, e.g., standard USB HID KB device.

Polychromatic illumination functionality under the standard keys (illumination elements <NUM>) is also coupled by keyboard composite controller <NUM> to standard keyboard device controller <NUM>. With proper software support in host <NUM>. Host <NUM> can control the illumination in general and the color under each key, in specific. For example, some game application may use it to indicate "hot keys" for game control. Lock indication illumination elements <NUM> is the embodiment of the indication <NUM> in <FIG>. Lock indication illumination elements <NUM> may be implemented using polychromatic light sources. In the case of direct connection between keyboard 100d and host <NUM>, keyboard composite controller <NUM> couples the lock indication illumination elements <NUM> to standard keyboard device controller <NUM> as well. In this case, the lock keys status commands from host <NUM> that comes as a response of pressing the lock keys (caps lock, num lock, scroll lock) will cause standard keyboard device controller <NUM> to illuminate lock indication illumination elements <NUM> with a default color, typically green or white.

KVM switch keys <NUM> are embodiment of keys <NUM> and <NUM> of keyboard 100d or keys <NUM> of keyboards 100a, 100b and 100c. KVM switch keys illumination elements <NUM> are embodiment of polychromatic illumination over keys <NUM> and <NUM> as well as indicator 114d and 116d of keyboard 100d and indicators <NUM>, <NUM> and <NUM> of keyboard 100a, 100b and 100c. KVM switch keys <NUM> and the corresponding KVM switch keys illumination elements <NUM> may be used, with proper software support as keyboard extensions such as multimedia or gaming extension keys. Keyboard composite controller <NUM> couples KVM switch keys <NUM> and KVM switch keys illumination elements <NUM> to standard keyboard device controller <NUM> as well and upon pressing these keys, standard keyboard device controller <NUM> send command to host <NUM> and upon host <NUM> illumination commands to standard keyboard device controller <NUM>, the elements is illuminated, optionally, by polychromatic color. During direct keyboard to host connection KVM switch keyboard device controller <NUM> is disabled.

When composite interface circuitry <NUM> detects a connection to KVM switch <NUM>, keyboard 100d behave differently, this different keyboard behavior, refers as "KVM switch mode".

In keyboard's KVM switch mode, composite interface circuitry <NUM> instructs keyboard composite controller <NUM> to split the responsibility of sensing, i.e., scanning the keys, between standard keyboard device controller <NUM> and KVM switch keyboard device controller <NUM>. Keyboard keys <NUM> are scanned by standard keyboard device controller <NUM> and KVM switch keys <NUM> by KVM switch keyboard device controller <NUM>. Composite interface circuitry <NUM> gets the keys press events commands, i.e., key make and break commands of keyboard keys <NUM>, from standard keyboard device controller <NUM> and the keys make and break commands of KVM switch keys <NUM> from KVM switch keyboard device controller <NUM>. In an exemplary embodiment of the invention, composite interface circuitry <NUM> open two devices i.e., composite device on interface <NUM>, alternatively, composite interface circuitry <NUM> communicate through two independent interfaces with KVM switch <NUM>. With regards to the indications, i.e., illumination elements (<NUM>, <NUM> and <NUM>), composite interface circuitry <NUM> instructs keyboard composite controller <NUM> to couple the indication elements to KVM switch keyboard device controller <NUM>. This coupling allows KVM switch 300to give the user a color indication regarding the active host as described in the embodiments of <FIG> described hereinabove. In addition, this coupling enables a secure KVM switch to control the lock indication illumination elements <NUM> (i.e., lock indicators <NUM>) in a secure manner as will be explained hereinafter. For keys <NUM> in KVM switch keys <NUM>, KVM switch keyboard device controller <NUM> only illuminates, in the color associate with the active host, the key corresponding to the active host, or in the case were the key <NUM> is used for selecting two or more hosts, only portion area of the key. For example, for the top key <NUM> labeled with '<NUM>' and '<NUM>' when host #<NUM> is the active (selected) host, only the area under the label '<NUM>' (top-left) will be illuminated with the color associated with host #<NUM>, while when host #<NUM> is the active (selected) host, only the area under the label <NUM> (bottom-right) will be illuminated with the color associated with host #<NUM>. Dissimilar to the illumination of the other keys, in keys <NUM> only one key, or area on the key, is illuminated while the other keys <NUM>, e.g., keys ('<NUM>'+'<NUM>', '<NUM>'+'<NUM>' and '<NUM>'+'<NUM>') are not illuminated.

For security reasons, lock indication illumination elements <NUM> in keyboard's KVM switch mode may be controlled by KVM switch keyboard device controller <NUM>. Composite interface circuitry <NUM> instructs keyboard composite controller <NUM> to couple lock indication illumination elements <NUM> to KVM switch keyboard device controller <NUM>. In this KVM switch mode, while lock keys (Caps Lock, Num Lock, Scroll Lock) make and break events are transmitted to host <NUM> through standard keyboard device controller <NUM>, the lock keys status commands from host <NUM>, i.e., the commands for lock keys states that targeted to be displayed by lock indication illumination elements <NUM> may returned to keyboard 100d through different interface path. In this path, the lock keys status commands transferred to KVM switch keyboard device controller <NUM>. Unlike in keyboard-host direct connection, KVM switch keyboard device controller <NUM> may illuminate the lock indication illumination elements <NUM> with polychromatic color that is associated with the active host. To complete the picture, reference is made now to the internal block diagram of the KVM switch <NUM>. The communication between keyboard 100d and KVM switch <NUM> is accomplished between composite interface circuitry <NUM> of the keyboard and composite interface circuitry <NUM> of the KVM switch. In an exemplary embodiment of the invention, both sides are communicating using logical level composite device protocol such as USB. Alternatively, complete independent interfaces are used, optionally, over the same cable and connector. For example, USB type C connectors might be used but both keyboard 100d and KVM switch <NUM> may use some of the non-mandatory USB pins, such as high-speed data pins to run a separate communication interface between a keyboard controller <NUM> in KVM switch <NUM> and KVM switch keyboard device controller <NUM> in keyboard 100d. Inside KVM switch <NUM> data, commands, or messages that was initiated by standard keyboard device controller <NUM> will be transferred by composite interface circuitry <NUM> to a host emulator <NUM>. Host emulator can communicate bidirectional with standard keyboard device controller <NUM> but can only send the keypress commands, i.e., the make and break events of the keys of the keyboard, to the active host <NUM>. This is done through switch <NUM> that selects the active host <NUM> and a unidirectional enforcing element <NUM> that transfer data only from host emulator <NUM> to a device emulator <NUM> that is connected to the active host. Active host <NUM> is communicate bidirectionally with device emulator <NUM> so that device emulator <NUM> may get the responses for lock keys press events, i.e., the lock keys status commands that are needed for setting of lock indication illumination elements <NUM>. However, since device emulator <NUM> cannot communicate back with host emulator <NUM>, device emulator <NUM> may communicate the lock keys status commands through a unidirectional enforcing element <NUM> and switch <NUM> to keyboard controller <NUM>. Keyboard controller <NUM> using the composite or separate interface between composite interface circuitry <NUM> in KVM switch <NUM> and composite interface circuitry <NUM> in keyboard 100d may communicate the lock keys status commands, that are the responses for lock keys presses, to KVM switch keyboard device controller <NUM>. Whenever enhanced cyber security for this functionality is required, device emulator <NUM> may create internally three signals on three wires, one for each lock indication. The first wire signals the Caps Lock state, the second wire signals the Num Lock state and the third wire signals the Scroll Lock state. These three signals from the device emulator, that is connected to the active host, are selected by switch <NUM> and go separately via point-to-point hardware wiring, switching or routing through keyboard controller <NUM>, composite interface circuitry <NUM>, composite interface circuitry <NUM>, KVM switch keyboard device controller <NUM>, and keyboard composite controller <NUM> to control lock indication illumination elements <NUM>. In other embodiments, the lock indication response goes through keyboard controller <NUM> to composite interface circuitry <NUM> that using the appropriate bus through the composite interface send the lock indication response to composite interface circuitry <NUM> that in its turn froward it to KVM switch keyboard device controller <NUM> that controls lock indication illumination elements <NUM>, optionally, with the appropriate color assigned to the active host.

KVM switch <NUM> also comprises KVM switch controller <NUM> (illustrated previously in <FIG>) that set the active host <NUM> using at least key presses over keys 310a - 310d on KVM switch <NUM> or key presses on keys <NUM> on keyboards 100a - 100d. The active host <NUM> selection is provided simultaneously to switch <NUM>, switch <NUM>, and keyboard controller <NUM>. Keyboard controller <NUM> transfer the active host data to KVM switch keyboard device controller <NUM> that control the feedback to the user using the polychromatic light sources in keyboard keys illumination elements <NUM>, lock indication illumination elements <NUM> and KVM switch keys illumination elements <NUM>.

In an exemplary embodiment of the invention, keyboard 100d comprise composite device. Lock keys make and break events are transferred from the keyboard through the KVM switch to the host <NUM> using a first device and the lock keys status commands are received from the host <NUM> through KVM switch <NUM> to the keyboard using a second device. Alternatively, keyboard 100d comprise two separate devices. The lock keys make and break events are transferred from keyboard to host through KVM switch using a first device and the responses are received from the KVM switch to the keyboard using a second device.

Claim 1:
A peripheral devices switching system configured to be coupled to a plurality of host computers (<NUM>), the system comprising:
at least one set of peripheral devices (<NUM>, <NUM>, <NUM>) ; and
a peripheral devices switch (<NUM>, <NUM>, <NUM>) that is configured to be coupled to said at least one set of peripheral devices and said plurality of host computers, wherein the peripheral devices switch (<NUM>, <NUM>, <NUM>) is configured to couple between said at least one set of peripheral devices (<NUM>, <NUM>, <NUM>) and an active host computer of the plurality of host computers (<NUM>),
characterized in that
at least one peripheral device of the at least one set of peripheral devices comprises one or more polychromatic light sources;
the peripheral devices switch (<NUM>, <NUM>, <NUM>) is configured to be assigned with a color corresponding to each host computer of the plurality of host computers (<NUM>), and
the peripheral devices switch (<NUM>, <NUM>, <NUM>) is configured to indicate the active host computer (<NUM>) by instructing the at least one peripheral device (<NUM>, <NUM>, <NUM>) to illuminate the one or more polychromatic light sources by the color that is assigned to the active host computer.