Black Box ACU2028A Appendix D Advanced Cabling Issues Skew, Dealing with Severe Skew, Green Delay

Page 56

APPENDIX D: ADVANCED CABLING ISSUES (SKEW)

Appendix D: Advanced Cabling Issues (Skew)

The suggestions made in this Appendix should only be investigated if you cannot obtain satisfactory image quality after configuring the Remote unit (as described in Section 4). The techniques described here are usually only necessary when you are operating at the highest screen resolution (1600x1200) with long Interconnect cables.

Dealing with Severe Skew

The CATx KVM extender provides a maximum skew compensation of 42nS. This is more than adequate for most cables. However, it may not be enough if a particularly long cable is used that exhibits severe delay skew. In this case, some of the procedures described below should be considered. In extreme cases, you should consider using an additional external delay line (Model: ACUDLY) or an alternative CATx cable as recommended by Technical Support.

Green Delay

Introducing delays in the video signals inevitably may cause some distortion. For example, it may result in pixels being sampled twice on TFT screens.

The human eye is extremely sensitive to green distortion. To obtain optimal video performance it is best to ensure that no green delay is required. You can visually check the relative pair delays by viewing the test card (without any delays applied). The two color bars on the left require delaying, but the color bar on the right requires zero delay (slowest) and is the reference. Ideally, green should be the reference signal.

If your system requires a large delay on the green signal, try using a crossover patch cable at each end of the link (instead of straight patch cables to connect to wall outlets). In many cases, the crossover should transfer the delay requirement to the blue signal rather than green. The human eye is much less sensitive to blue distortion and so video quality can be improved. Check the result using the test card and adjust the delays accordingly. The main cable should be wired according to EIA-568B as shown below.

55

Image 56
Contents ACUR001A ACUR002A ACURA001A ACURA002A Welcome to the ServSwitch Family Servswitch FamilyServswitch Brand Catx KVM Extender Family Copyrights and TrademarksFCC/CDC Statements European Union Declaration of Conformity NOM Statement Servswitch Brand Catx KVM Extender Family Safety Precautions and Installation Guidelines Safety Precautions and Installation GuidelinesContents Contents Quick Setup Command Summary Quick SetupIntroduction GlossaryOverview Features Product Range Compatibility Interface CompatibilityExtender Compatibility ACU1049AHow to Use This Guide Adjusting VideoConnection & Compatibility Interconnection CableInstallation Package ContentsInstallation Interconnection Cable RequirementsRemote Unit Installation RemoteUnit Audio DeviceRemote Unit front view Local Unit Installation Computer Local UnitLocal Unit Dual Video rear view Local Unit Dual Video front view Connection to Rackmount Hub Local Units Remote Units Compatible Local Rack HubsSimple system using ACU1006RA hub and ACUR001A ACU1006RA rack used with ACUR002A units to extend Remote Unit Configuration & Operation Video Configuration OverviewVideo Adjustments Remote Unit Configuration & OperationAssisted EQ Quick SkewKeyboard LED flashes Video channel Command ModeStatus LEDs in Command Mode Adjusting Video Online test card available atLeft Control + Home Problems with smearing and sharpness requiring LF Red Remote Unit Configuration & Operation Other Remote Configuration & Operation Options Reset CommandsPrivate Mode Commands Local Unit Scroll Lock Key Mode Local Unit Configuration CommandsCommand Key Sequence Local Unit Initial Hot Key Power OverviewLocal Unit Operation Keyboard and Mouse EmulationDual Access Systems Changing the Initial Hot KeyLocal Console Commands Command Key Sequence Private Mode Scroll LockReset Local Keyboard and Mouse Num-Pad Up Arrow Send Null Mouse Byte Num-Pad Left ArrowCan’t get enough color delay to correct skew VideoImage is not sharp, or is badly smeared Can’t get rid of bright ‘ringing’ after charactersTroubleshooting Keyboard & Mouse Audio SerialGeneral Questions Can the extender be daisy chained?Which interconnection cable is best? Can the extender system be used between buildings?Appendix a Example Applications Appendix a Example ApplicationsDual-monitor consoles with serial and audio extension Touch screen network with local access to CPU through Information distribution system sharing a single PC Extender system with second screen for security monitoring Appendix B Rack Mount Options RMK19U-X3 Mounting KitAppendix B Rack Mount Options RMK19U-R2 Mounting KitUpgrade Cable Part No Acuflh Dealing with Severe Skew Appendix D Advanced Cabling Issues SkewGreen Delay Cable Pinning/Pairing Pin Color Signal EIA-568BOptimizing Pairs General Solution Pins Pair SignalSerial Interface Handling Multiple Serial Devices Operation & Multi-Port ConfigurationSerial Interface Set Up and Operation Appendix E AUDIO/SERIAL Ports Audio Interface Set Up and OperationAudio Interface Using a Microphone Appendix F Calling Black Box Shipping and PackagingAppendix G Specifications Signal levels Local Unit ConnectorsRemote Unit connectors Local Power UnitOperating Temperature Storage TemperatureACU2201A ACU2222APage Customer Support Information