Crestron electronic AV2 - Manual (Page 30)

2-Series Integrated Dual Bus Control System Crestron AV2 & PRO2
NOTE: Any of the six-menu function buttons toggles the “freeze” state.
NOTE: The buffer recycles data even when in the “freeze” state. When the screen is
unfrozen, the display jumps to the end of the buffer.
T/R Screen with Frozen Sample
Check Network Wiring
Use the Right Wire In order to ensure optimum performance over the full range of your installation
topology, Crestron Certified Wire, and only Crestron Certified Wire, may be used.
Failure to do so may incur additional charges if support is required to identify
performance deficiencies because of using improper wire.
Calculate Power CAUTION: Use only Crestron power supplies for Crestron equipment. Failure to
do so could cause equipment damage or void the Crestron warranty.
CAUTION: Provide sufficient power to the system. Insufficient power can lead to
unpredictable results or damage to the equipment. Please use the Crestron Power
Calculator to help calculate how much power is needed for the system
(
http://www.crestron.com/calculators ).
When calculating the length of wire for a particular Cresnet run, the wire gauge and
the Cresnet power usage of each network unit to be connected must be taken into
consideration. Use Crestron Certified Wire only. If Cresnet units are to be daisy-
chained on the run, the Cresnet power usage of each network unit to be daisy-
chained must be added together to determine the Cresnet power usage of the entire
chain. If the unit is a home-run from a Crestron system power supply network port,
the Cresnet power usage of that unit is the Cresnet power usage of the entire run.
The wire gauge and the Cresnet power usage of the run should be used in the
following equation to calculate the cable length value on the equation’s left side.
Cable Length Equation
L = Length of run (or chain) in feet
R = 6 Ohms (Crestron Certified Wire: 18 AWG (0.75 MM ))
or 1.6 Ohms (Cresnet HP: 12 AWG (4 MM ))
P = Cresnet power usage of entire run (or chain)
2
2
L <
40,000
R x P
Where:
Make sure the cable length value is less than the value calculated on the right side of
the equation. For example, a Cresnet run using 18 AWG Crestron Certified Wire and
drawing 20 watts should not have a length of run more than 333 feet. If Cresnet HP
is used for the same run, its length could extend to 1250 feet.
NOTE: All Crestron certified Cresnet wiring must consist of two twisted pairs. One
twisted pair is the +24V conductor and the GND conductor, and the other twisted
pair is the Y conductor and the Z conductor.
26 • 2-Series Integrated Dual Bus Control System: AV2 & PRO2 Operations Guide – DOC. 5957B