Page 8
BlockHead™ II User Manual Rev. A
(c) 2015 Blizzard Lighting, LLC
3. SETUP
Fuse Replacement
With a Philips screwdriver, unscrew the fuse holder out of its housing and
remove the blown fuse from its holder. Replace the blown fuse with a
fuse of the exact same type and rating, then screw the fuse holder back
into place and reconnect power.
Connecting A Bunch of BlockHead™ II Fixtures
You will need a serial data link to run light shows using a DMX-512
controller or to run shows on two or more fixtures set to sync in master/
slave operating mode. The combined number of channels required by all
the fixtures on a serial data link determines the number of fixtures the
data link can support.
Fixtures on a serial data link must be daisy chained in one single line.
Also, connecting more than 32 fixtures on one serial data link without the
use of a DMX optically-isolated splitter may result in deterioration of the
digital DMX signal.
The maximum recommended cable-run distance is 500 meters (1640 ft).
The maximum recommended number of fixtures on a serial data link is
32 fixtures.
Data/DMX Cabling
To link fixtures together you’ll need data cables. You should use data-
grade cables that can carry a high quality signal and are less prone to
electromagnetic interference.
For instance, Belden© 9841 meets the specifications for EIA RS-485
applications. Standard microphone cables will “probably” be OK, but note
that they cannot transmit DMX data as reliably over long distances. In
any event, the cable should have the following characteristics:
2-conductor twisted pair plus a shield
Maximum capacitance between conductors – 30 pF/ft.
Maximum capacitance between conductor & shield – 55 pF/ft.
Maximum resistance of 20 ohms / 1000 ft.
Nominal impedance 100 – 140 ohms
