Studio Technologies 76DA V.3.01 - Manual (Page 15)

Model 76DA/77 User Guide Issue 2, April 2011
Studio Technologies, Inc. Page 15
for Surround
the selected cable will support the desired
interconnection length. Calculate the volt-
age drop by multiplying the total resistance
(in ohms) of the proposed cable by 0.1 (the
Model 77’s required current in amperes).
Remember to include the resistance in both
the DC + and DC – wires when calculating
the voltage drop. If it’s greater than 3 volts
your cable is too long or the wire gauge is
too small.
Additional Control Consoles
Some installations may benefit from the
Model 76DA’s ability to be controlled by ad-
ditional control consoles. At least one Model
77 Control Console must be connected to
the Model 76DA Central Controller. After
this requirement has been met up to three
additional Model 77 or Model 71 Control
Consoles can also be connected and pow-
ered by the Model 76DA.
When connecting multiple control consoles
to a Model 76DA all nine pins of each inter-
connecting cable can be connected in par-
allel (“multed”). Using this arrangement the
data and 12 volt DC power signals between
all the units will be multed. A custom cable
implementation requires just four pins to be
connected: pin 1 (data +), pin 6 (data –),
pin 4 (DC +), and pin 9 (DC –).
To make installation simple, a “bus” cable
assembly can be created using a short
length of ribbon cable with one male
and multiple female 9-pin D-subminiature
insulation-displacement connectors
attached. Then standard 9-pin cables can
link the control consoles with the connec-
tors on the bus cable.
Refer to the previous paragraphs of this
user guide where the issues involving
Model 76DA to Model 77 cable length are
discussed. Note the required current for a
Model 77 is 100 milliamperes while a Mod-
el 71 requires only 35 milliamperes. It’s
important to review this information prior to
creating the interconnection scheme to be
used for installing multiple Model 77 units.
AC Mains Power
The Model 76DA operates directly from
AC mains power of 100 to 230 V, 50/60 Hz.
Being a “universal input” device, there are
no switches to set or jumpers to install to
match a location’s mains voltage. The unit
uses a 3-pin IEC 320 C14-type inlet con-
nector to mate with a detachable mains
cord. All units are supplied with a mains
cord that has a North-American standard
plug (NEMA 5-15L) on one end and an
IEC 320 C13 socket on the other. Units
bound for other destinations require that
the appropriate cord be used. The wire
colors in the mains cord must conform to
the internationally recognized color code
and should be terminated accordingly:
Connection Wire Color
Neutral (N) Light Blue
Line (L) Brown
Protective Earth (E) Green/Yellow
Safety Warning: The Model 76DA
does not contain an AC mains dis-
connect switch; the AC mains cord
plug serves as the disconnection
device. Safety considerations require
that the plug and associated outlet
be easily accessible to allow rapid
disconnection of AC mains power
should it prove necessary.