Studio Technologies 76D 2014 - Manual (Page 13)

Model 76D/77 User Guide Issue 11, May 2014
Studio Technologies, Inc. Page 13
for Surround
to be high-impedance (“floating”) or ter-
minated with an impedance of 75 ohms.
A sync source that is dedicated for use by
the Model 76D’s sync input will typically
have input termination enabled. If the sync
signal connected to the Model 76D is be-
ing connected (“multed”) to other inputs it
may be desirable for the termination to be
disabled. A general “rule of thumb” is that
termination should be applied only at the
location of the last physical device using
a sync signal.
Remote Control Inputs
Support is provided for two remote con-
trol input functions: remote mute all and
remote dim. These functions only impact
the post-fader surround and stereo monitor
outputs. The Model 76D’s inputs use logic
gates, “pulled up” to 5 volts DC by way of
resistors, which are active whenever they
are brought to their logic low state. Inputs
of this type are commonly referred to as
GPI inputs. While the input circuitry is
protected from over-current and static dis-
charge (ESD), care should be taken to pre-
vent nasty signals from reaching them. The
inputs are active only when held in the low
state; they can’t be configured to change
state (“latch”) in response to a logic pulse.
A 9-pin D-subminiature connector is
used for the remote control inputs. Refer
to Figure 5 or Appendix A for the exact
connection details. Note that pin 4 (remote
common) connects to the Model 76D’s
internal circuit common connection as well
as to the Model 76D’s chassis and mains
earth connections. Figure 5 also shows
two spare remote control inputs (pins 8
and 9). These are provided for future
applications and should remain uncon-
nected. This connector also allows access
to an RS-485 data interface. This interface
Signal Pin Direction
Data + (RS-485/RS-422) 7 Not used
Data – (RS-485/RS-422) 2 Not used
Data Shield 1 Shield
Remote Mute All 5 Input
Remote Dim 6 Input
Remote Spare 1 8 Input
Remote Spare 2 9 Input
Remote Common 4 Common
Note: Connector type on Model 76D is 9-pin female
D-subminiature (DE-9F). Connector uses 4-40
threaded inserts for locking with mating plug.
Figure 5. Connections for Remote Control
Inputs
is not supported in the Model 76D and,
as such, pins 7 and 2 should remain
unterminated.
Connecting the Model 76D
to the Model 77
A 9-pin female D-subminiature connector,
labeled To/From Control Consoles, is pro-
vided on the back panel of the Model 76D
Central Controller. This is used to interface
the unit with Model 77 Control Consoles.
Refer to Figure 6 or Appendix A for details.
A 9-pin female D-sub connector, labeled
To/From Central Controller, is provided on
the back panel of each Model 77 Control
Console. A cable with 9-pin male D-sub
(DE-9M) connectors on each end is used
to interconnect the Model 76D with the
Model 77 units. A cable is included in the
shipping carton. The cable implements
all nine connector pins in a one-to-one
manner.