Model 760-03/77 User Guide
Issue 4, October 2016
Studio Technologies, Inc.
Page 49
for Surround
reo input C direct monitor output can
be connected to other devices that find
need for the now-synchronized signal. In
some cases it may be useful to connect
the stereo input C direct monitor output
to the input of a signal router, allowing an
entire facility to access the signal.
Model 760-03 to Control
Console Connections
Figure 8 gives a detailed description of
the signals that connect the Model 760-
03 Central Controller to the one or more
Model 77 or Model 71 Control Consoles.
The Model 760-03 provides 12 Vdc for use
by the control console’s circuitry. The DC
output is current-limited to minimize the
chance that a short-circuit condition will
damage the Model 760-03’s circuitry. An
asynchronous, bi-directional data interface
links the connected units. The RS-485
hardware connection scheme operates at
a rate of 115.2 kbit/s and uses an 8-N-1
data format. The Model 760-03 communi-
cates with each Model 77 and Model 71
unit 20 times per second, receiving button
and rotary level control information and
sending LED and 4-digit display status
data.
“Hot” Disconnection of
Control Consoles
There’s no problem relocating one or more
Model 77 or Model 71 Control Consoles
while the StudioComm system is operat-
ing. You can disconnect the 9-pin intercon-
necting cable, move the unit (or units), and
then reconnect without issue. Upon discon-
nection of all control consoles the Model
760-03 Central Controller will mute the
internal digital audio channels as well as
saving the current operating parameters.
No clicks, pops, or other noises will occur
when the Model 77 or Model 71 units are
again connected. The control consoles
will go through their standard power-up
sequence and then normal operation will
resume.
Channel Status, User, and
Validity Bits
The non-audio bits that are part of the
AES3 digital audio monitor output channel
data are actively controlled by the Model
760-03’s software. The Channel Status
bits use the Professional Use of Channel
Status block. They indicate a word length
of 24 and the current sample rate. The cor-
rect CRC is also calculated and inserted.
The User bits are always set to 0. When
a valid timing reference (sync) source is
recognized by the system the Validity bits
will be set to 1.
The Model 760-03’s hardware is capable
of routing the C/U/V bit information from
any of the L/R inputs, as well as the sync
input, to the main logic device (FPGA)
and then on to the digital audio transmitter
(DIT) integrated circuits. This is provided
for future use and is not active at this time.
