Gilderfluke&Co BR-ANA Analog Output Smart/Dumb Brick - Manual (Page 25)

A DMX-512 network can be as long as a mile, or as short as a few
inches. The DMX-512 network needs to be one long line, with no long side
branches. If the network is longer than a few feet, you may need to provide a
terminating resistor at the two far ends of the network (120Ω, ½ Watt is typi-
cally used). The resistors suppress ʻechosʼ on the DMX-512 wires.
If the network runs throughout a facility, it is prudent to use a some iso-
lated splitters. These will keep an electrostatic zap or lightning hit on the
network from damaging the entire network. An isolated splitter also allows
you to run side branches on the network, since each isolated branch is
treated as a separate DMX-512 network (daisy chained from DMX-512
ʻSlaveʼ to ʻSlaveʼ, it can be run up to a mile, and may need its own termina-
tion resistors).
Addresses 256 and 257 are optionally used in GilderGear for transmitting
a checksum. The Br-ANA can use this to verify that the data received from
PC•MACs has no transmission errors in it. If you address a light dimmer or
other DMX-512 device to addresses 256 or 257, you will see this verification
data displayed as a flickering pattern. Most GilderGear will automatically
start requiring GilderChecksums after receiving DMX-512 that has Gilder-
Checksums in it. Once it starts requiring GilderChecksums, the only way to
get the Br-ANA to stop requiring it is to cycle power on the Br-ANA.
Note that at higher frame rates, not all 512 channels can be transmitted
through DMX-512. This is why it is unusual to run shows over 30 FPS.
The typical wires used for carrying a DMX-512 network are a single
shielded twisted pair or wires. For short runs, just about any ʻmicrophone
cableʼ can be used. For longer runs, a low capacitance twisted pair is rec-
ommended. Recommended wires include:
Manufacturer Part # Gauge Wire Stranding
Belden 3105A 22 AWG 7 x 30
Belden 3106A 22 AWG 7 x 30
Belden 9841 24 AWG 7 x 32
Belden 7200A 24 AWG 41 x 40 (high flexibility)
Proplex PC222P 22 AWG 19 x 34
Dataplex WDP222TBK 22 AWG 16 x 0.2mm
Gilderfluke & Co.• 205 South Flower Street • Burbank, California 91502 • 818/840-9484 • 800/776-5972 • fax 818/840-9485
Br-ANA Manual / December 18, 2012 10:21 AM / page 25 of 60