User Guide

Issue 4, December 2020 Model 780-01/790 User Guide
Page 42 Studio Technologies, Inc.
for Surround
flash. On all connected Model 790 Control
Consoles the 4-digit LED display will cease
normal operation, instead alternating
between the words no and sync. When
a valid sync signal is again connected
the Model 780-01’s sync status LED will
light steadily. On the Model 790 units the
word sync will momentarily be displayed
followed by a brief display of the active
sample rate. The sample rate will display
as 44.1, 48.0, 88.2, or 96.0, reflecting the
impact of the sync source rate and the
Model 780-01’s configuration.
If during normal operation the sync source
changes from one valid rate to another a
visual indication is provided. On the Model
790 units the new sample rate—44.1,
48.0, 88.2, or 96.0—will momentarily be
displayed.
Any time that a valid sync signal is not
connected to the Model 780-01 the monitor
outputs will automatically revert to an inter-
nally generated sample rate of 48 kHz with
no digital audio content present. This audio
“black” signal will allow most connected
equipment to continue to function correctly
with, of course, no meaningful audio signal
present. As soon as a valid sync signal is
again connected to the Model 780-01 the
monitor outputs will automatically switch to
their correct sample rate and audio signals
will again be present.
Power Down
Care was taken in the Model 780-01’s
design to minimize the chance that objec-
tionable clicks, pops, or other obnoxious
audio signals will be present on the moni-
tor outputs. A power-down circuit supplies
the main microcontroller integrated circuit
with an indication that a power loss is
imminent. When this condition is detected
the monitor outputs will switch to silence
(digital audio “black”) in preparation for a
complete loss of signal.
Power-Up Messages
Upon mains power being applied to the
Model 780-01 all connected Model 790 units
will go through a power-up sequence. The
sequence starts by each of the individual
LEDs lighting in a “walk-through” sequence.
Then the 4-digit display tests all its LED
segments. Finally, a set of messages pro-
vide details on the specific Model 790 and
connected Model 780-01 software versions:
1. Displays 790
2. Displays Model 790’s software version
3. Displays Model 790’s unit address
(A1, A2, A3, or A4)
4. Displays 780
5. Displays Model 780-01’s main software
version
6. Displays FPgA
7. Displays Model 780-01’s logic device
(FPGA) software version
After a successful system power-up
sequence normal operation will then
commence.
Error Codes
Should a problem be encountered during
power up one of four error codes may
show on the Model 790’s 4-digit display.
Error Code Err1
Err1 indicates that communication is not
taking place between the Model 790 and
the Model 780-01. The most likely cause
would be incorrect wiring of the data pair
linking the two units.