Lindy 32 341, 32 342 manual Setting the USB enumeration guard time option switches 5

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2.4.1Setting the USB enumeration guard time (option switches 5 and 6)

A USB-enabled computer detects and configures USB peripherals when they are connected to or disconnected from its USB ports. This process is called enumeration. You can often see when the enumeration process is in progress as the computer will usually display a timer or hourglass for a few seconds after the connection of a USB peripheral whilst the device is being enumerated.

This enumeration process will take place each time that the LINDY CPU Switch USB locks on to a new computer port. Unfortunately computer software is not generally robust enough to cope with the connection between the computer and peripherals being broken during this enumeration process. If the connection is lost part of the way through the enumeration process then the computer software or the peripherals can hang.

To overcome this problem the LINDY CPU Switch USB is fitted with an enumeration guard timeout system. Once the LINDY CPU Switch USB has locked on to a channel it will remain connected to that channel for at least the enumeration guard time. This ensures that the enumeration process is complete before further channel changes are allowed and consequently ensures robust and reliable operation.

The enumeration process takes longer if more peripherals are connected. Select an enumeration time that is longer than the longest observed enumeration time. The enumeration time can be judged by the length of time that the hourglass or timer remains on the computer screen after a channel change (normally a few seconds). Alternatively you may select the shortest enumeration guard time (2 seconds) and remember not to change the channel whilst the hourglass or timer is displayed.

2.4.2 Setting the autoscan dwell time

The LINDY CPU Switch USB may be made to autoscan the connected computers. During autoscan the LINDY CPU Switch USB displays the video signal from each computer in turn for a selected time period. This time period is known as the dwell time and may be selected to be 2 or 5 seconds using option switch 7. Ports are scanned in ascending numerical sequence and all the ports or just the active ports ￿will be scanned according to the setting of option switch 8.

LINDY CPU Switch USB

Installation and Use

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Contents Part Model Lindy CPU Switch USB Installation and UseAbout this manual Safety informationTrademarks WarrantyPage European EMC directive 89/336/EEC Radio Frequency EnergyContents Problem Solving Cable specificationsPC and MAC models Key featuresIntroduction Remote controller contents part code 32 Product information Lindy CPU Switch USB model 32Remote control pad / display optionalaccessory Part 32 What you will need InstallationConnecting your devices Mounting the Lindy CPU Switch USBInstallation and Use Lindy CPU Switch USB Lindy CPU Switch USB Installation and Use = on Configuring the Lindy CPU Switch USBSetting the autoscan dwell time Setting the USB enumeration guard time option switches 5Setting the keyboard hotkey combination model 32 341 only Re-enabling a disconnected Lindy PS/2 mouse 32 341 only Powering on the Lindy CPU Switch USBConfiguring your computers Installation and Use Lindy CPU Switch USB Front panel key Using the Lindy CPU Switch USBPower on status Status display Switching between computers using the Lindy CPU Switch USBKeyboard hotkey control model 32 341 only Installation and Use Lindy CPU Switch USB Mouse control model 32 341 only Autoscan modeOptional remote controller IBM 104/105-key Apple keyboard Keyboard Querying the Lindy CPU Switch USB’s firmware versionPC and Macintosh keyboard equivalent key mappings A2. Video cables Appendix A. Cable specificationsA1. USB cables A3. PS/2 style keyboard and mouse extension cables A4. Remote controller extension cablesAction Appendix B. Problem SolvingProblem