QSC Audio RAVE 81 Benutzerhandbuch

in that its deterministic nature affords a bit more tolerance of delay than unregulated, non-deterministic network

traffic can handle: a network span or diameter of up to 2560 bit periods (with Fast Ethernet, 1 bit period = 10

nanoseconds), or 25.6 microseconds. Unless you are designing very large and complicated RAVE networks,

though, you’re highly unlikely to reach these limits. For further guidance on designing large-scale networks,

consult the RAVE Application Guide or see the CobraNet network guidelines on Peak Audio’s web site at

http://www.peakaudio.com.

As mentioned before, the maximum Category 5 UTP cable length between two network devices—that is, between

any RAVE unit, hub, repeater, switch, etc., and any other—is 100 meters, or 328 feet. You can cover longer

distances by using optical fiber, as mentioned earlier, or by running 100-meter lengths of UTP cable linked by

Fast Ethernet hubs. The latter solution is practical mainly if you need, or are likely to need, RAVE units at the

intermediate points, and possible only if you have power sources for all the Fast Ethernet hubs. Ultimately, the

cumulative round-trip propagation delays of all the cables (typically 1.112 bit periods/meter) and intervening hubs

(Class I hub: < 140 bit periods; Class II hub: <92 bit periods) imposes a limit on how far you can carry this sort

of configuration. See the CobraNet network guidelines at the Peak Audio web site (cited above) for further

guidance, especially if you are designing a CobraNet network whose span approaches or even exceeds 1000

meters.

A fiber optic run of typical 62.5 µm multimode fiber can be up to 2 kilometers, or 6560 feet or 1.24 mile. Single-

mode fiber is a much higher grade and can thus handle longer distances, but the specific limit hasn’t been

determined, and largely depends on the hardware involved. Consult the manufacturer of the media converters

you use.

Although a RAVE network has a capacity of 64 audio channels—i.e., eight network channels, each with eight

audio channels—there is no set limit to the number of receivers that a RAVE network will support, except that

as you add more hubs and cabling, the data delays will increase.