AV Connectivity & Signal Distribution - CIE-Group

40Installation Advice and InformationDataBay Signal Distribution ProductsThe DataBay range of AV signal distributionequipment is capable of high quality results.This guide is intended to help achieve optimumperformance from the equipment by followingsimple guidelines and good installationpractice.Cable:The DataBay product range distributes the AVsignals via various cable types. As with anyinstallation, the type and quality of cable can havea dramatic effect on the resultant performance.For example, a CCTV system may be installedwith all manner of RG59 cable, but the resultantdifferences in image quality from best to worst canbe huge.Where a DataBay system is extended viaCat5e / Cat6 cable, we strongly recommend theuse of a Low Skew cable. Skew is a measurement(normally in nanoseconds) that measures thetime delay between the first and last signal arrivalin different twisted pairs. If the time difference istoo large, image quality can be affected, possiblymanifesting itself in bright vertical lines, ghosting,colour smudging or worst case, no image at all.Low Skew in video terms is cable with Skew rateslower than 15nS per 100m.The following Cat-X cables should all performwell:Belden 7987RBelden 1700ACanford 31-953Mohawk M58813Environmental issues:The area surrounding an installation can alsohave an impact on its performance. In particularelectrical noise from mains cables, fluorescentlighting or electric motors / installations, etc, couldresult in interference being induced into the AVcabling system and affecting its performance.The same applies to airborne radio frequencyinterference.Common sense and good installation practiceshould minimise these effects through carefulcable routing, avoiding mains cables or otherareas of potential interference. In areas of highsusceptibility, it would be sensible to use low skewscreened cables.Display resolutions and refresh rates:Higher display resolutions and video refresh ratesall require higher bandwidths and data rates.The result of the greater demands on the cable is,consequently, reduced achievable distances.For example:A display running a resolution of 480p may happilywork across a 100m link; the same infrastructurerunning a display @ 1080p may only achieve30m.FAQQ. What is Low Skew Cat-X cable?A. Skew is a measurement (normally innanoseconds) which measures signaldelays between different twisted pairs in acable. Low Skew in video terms is cablewith Skew rates lower than 15nS per 100m.Q. Can I extend the distances further thanspecified?A. This could be possible by:- Reducing the display resolutions- Using better quality Cat-X cable(low skew, shielded)- Using better quality video cables(e.g. Cat2 HDMI cable)Q. I’m only using a 5 metre Cat-X link cablebetween the transmitter and receiver, but Icannot get a picture...A. This can occur when using short cables ofmaybe 5 or 10 metres with receivers that areoptimised to function over much longerdistances e.g. 300m. In this case eitheruse a slightly longer Cat-X cable or use adifferent receiver.Q. I’m using a short range HDMI non-poweredreceiver (p/n HDMI-HR), but cannot see animage; why?A. Some flat panel monitors use a slightlynon-standard input which requires powerat the HDMI input socket to functioncorrectly. Some Samsung and Goodmansmonitors are known to suffer from thisissue (there may be others). However, theproblem can be easily overcome byusing our p/n ET-HC0101-Z (see page 17),in place of the non-powered HDMI-HR.Q. If I ‘mix’ transmitters and receivers of differentdistance capabilities (e.g. AVE-301T 300mand the receiver from the AVE-M180TR180m), what is the maximum distanceachievable?A. In all such cases you are limited to thedistance of the shortest device (in thiscase 180m).Q. How many levels of cascading can beachieved on HDMI?A. Normally two is recommended, although atlower resolutions and with good qualitycables further cascading may be perfectlypossible.Q. Can I use stranded Cat-X patch cord?A. Stranded Cat-X cable is not recommended– use solid installation Cat-X cable forbest results.Q. How should I wire the Cat-X cable?A. The cable should be terminated to EIA 568Bspecifications.1 2 3 4 5 6 7 8EIA 568B specifications:Pair 3Pair 2 Pair 1 Pair 41 2 3 4 5 6 7 8Jack PositionThe EIA/TIA definition of 568B in the pin assignment is (1) orangewhite, (2) orange, (3) green white, (4) blue, (5) blue white, (6)green, (7) brown white, and (8) brownwww.databay.uk.com