Studio Technologies 76D V.2.02 - Manual (Page 14)

Issue 2, June 2009 Model 76D/77 User Guide
Page 14 Studio Technologies, Inc.
for Surround
the resistance in both the DC + and
DC – wires in the figure for the total resis-
tance. 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 76D’s ability to be controlled by ad-
ditional control consoles. As expected, at
least one Model 77 Control Console must
be connected to a Model 76D Central Con-
troller. After this requirement has been met
up to three additional Model 77 or Model 71
Control Consoles can also be connected
and powered by the Model 76D.
When connecting multiple control consoles
to a Model 76D all nine pins of each inter-
connecting cable can be connected in
parallel (“multed”). This will electrically
mult the data and 12 volt DC power signals
between all the units. 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 insu-
lation-displacement connectors attached.
Then standard 9-pin cables can link the
control consoles with the connectors on
the bus cable.
Refer to the previous paragraphs of this
user guide where the issues involving
Model 76D to Model 77 cable length are
discussed. Note the maximum required
current for a Model 77 is 100 milliamperes
while a Model 71 requires only 35 milliam-
peres. It’s important to review this informa-
tion prior to creating the interconnection
scheme to be used for installing multiple
Model 77 units.
AC Mains Power
The Model 76D 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
connector to mate with a detachable mains
cord. All units are supplied with a mains
cord that has a North-American standard
plug (NEMA 15L) on one end and an IEC
320 C13 socket on the other. Units bound
for other destinations require that the ap-
propriate 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 76D does
not contain an AC mains disconnect
switch. As such, 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 dis-
connection of AC mains power should
it prove necessary.
As soon as mains power is applied
the Model 76D will perform a power-up
sequence. The two LEDs on the right side
of the front panel will individually light in a
rapid right-to-left test sequence. Then the
LEDs will flash in cadence while the firm-
ware loads into the Model 76D’s main logic
device. After just a few seconds normal
operation can commence and the LEDs
will perform their intended functions. Once