Studio Technologies 76DA V.4.00 - Manual (Page 14)

Issue 3, July 2012 Model 76DA/77 User Guide
Page 14 Studio Technologies, Inc.
for Surround
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 digital
and analog monitor outputs. The Model
76DA’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 discharge (ESD), care
should be taken to prevent 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 6 or Appendix A for the exact con-
nection details. Note that pin 4 (remote
common) connects to the Model 76DA’s
internal circuit common connection as well
as to the Model 76DA’s chassis and mains
earth connections. Figure 6 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
is not supported in the Model 76DA
and, as such, pins 7 and 2 should remain
unterminated.
Connecting the Model 76DA
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 76DA
Central Controller. This is used to interface
the unit with Model 77 Control Consoles.
Refer to Figure 7 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 76DA 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.
Should an interconnecting cable of a differ-
ent length be required there’s no problem
for one to be fabricated and used. While it
Signal Pin Direction
Data + (RS-485) 1 To/From Models 77/71
Data – (RS-485) 6 To/From Models 77/71
Data Shield 2 To/From Models 77/71
DC + (12 V) 4 To Models 77/71
DC – (12 V Return) 9 To Models 77/71
DC Power Shield 5 To/From Models 77/71
Note: Connector type on Model 76DA is 9-pin D-subminiature
female (DE-9F). Connector uses 4-40 threaded inserts
for locking with mating plug.
Figure 7. Connections between Model 76DA and
Model 77 and Model 71
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 76DA is 9-pin D-subminiature
female (DE-9F). Connector uses 4-40 threaded inserts
for locking with mating plug.
Figure 6. Connections for Remote Control
Inputs