User Guide

Model 780-01/790 User Guide Issue 4, December 2020
Studio Technologies, Inc. Page 13
for Surround
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 (DE-9F)
is used for the remote control inputs. Refer
to Figure 6 or Appendix A for connection
details. Note that pin 4 (remote common)
connects to the Model 780-01’s internal
circuit common connection as well as to
the Model 780-01’s chassis and mains
earth connections. Figure 6 also shows
two spare remote control inputs (pins 8
and 9). These are provided for future ap-
Control Consoles. Refer to Figure 7 or
Appendix A for details. A 9-pin female
D-sub connector (DE-9F) labeled To/From
Central Controller, is provided on the back
panel of each Model 790 Control Console.
A cable with 9-pin male D-sub (DE-9M)
connectors on each end is used to inter-
connect the Model 780-01 with the Model
790 units. A cable, approximately 20 feet
(6 meters) in length, is included in the ship-
ping carton. The cable implements all nine
connector pins in a one-to-one manner.
Should an interconnecting cable of a
different length be required there’s no
problem for one to be fabricated and used.
While it can be wired in a one-to-one fash-
ion supporting all nine pins, only four con-
nections are actually required: pin 1 (data
+), pin 6 (data –), pin 4 (DC +), and pin 9
(DC –). The Model 780-01’s connector pin-
out scheme was designed to allow creation
of an interconnecting cable which uses
commonly available 2-pair audio cable.
This cable, consisting of two twisted pairs
each with an individual shield, is typically
small in diameter, flexible, and available in
many colors. One pair and shield can be
used for the data connection (pins 1 and 6)
while the other pair and shield can be used
for the DC connections (pins 4 and 9). This
Signal Pin Direction
Data Shield 1 Shield
Remote Mute All 5 Input
Remote Dim 6 Input
Remote Spare 1 8 In
put
Remote Spare 2 9 Input
Remote Common 4 Common
Note: Connector type on Model 780-01 is 9-pin female
D-subminiature (DE-9F). Connector uses 4-40
threaded inserts for locking with mating plug.
Figure 6. Connections for Remote Control
Inputs
Signal Pin Direction
Data + (RS-485) 1 To/From Models 790/71
Data – (RS-485) 6 To/From Models 790/71
Data Shield 2 To/From Models 790/71
DC + (12 V) 4 To Models 790/71
DC – (12 V Return) 9 To Models 790/71
DC Power Shield 5 To/From Models 790/71
Note: Connector type on Model 780-01 is 9-pin female
D-subminiature (DE-9F). Connector uses 4-40
threaded inserts for locking with mating plug.
Figure 7. Connections between Model 780-01
and Model 790 and Model 71
plications and should remain unconnected.
Connecting the Model 780-01
to the Model 790
A 9-pin female D-subminiature connector
(DE-9F), labeled To/From Control Con-
soles, is provided on the back panel of the
Model 780-01 Central Controller. This is
used to interface the unit with Model 790