Crystal Vision
Using card edge controls
The top amber ‘SIL’ LED indicates that either the left or right channel of the analogue
stereo 1 signal has been silent, while the bottom ‘SIL’ LED shows that either the left or
right channel of the analogue stereo 2 signal has been silent.
Card edge switches may be used to prevent silence detection from raising alarms via these
GPI outputs.
Setting SW3 lever 4 low disables both Stereo 1 silence from asserting GPO5 low and
Stereo 2 silence from asserting GPO6 low. However, loss of the selected reference input
ALWAYS asserts GPO5 and GPO6 low, even if a suitable alternative reference has been
automatically selected to sustain a locked sample rate and correct AES output frequency
and phasing.
Lever
Function
4
Down = Disable both stereo input silence warning GPI outputs, Up = Enable
Note:
The routing of ‘Loss of Reference Input’ warning to the GPI port cannot be disabled.
Setting the silence threshold
The Hex rotary switch, ‘SIL TIME’ is used to set the required sustained silence period
before the LED indicators are illuminated and associated warnings raised. Switch position
‘0’ provides 1.5 seconds of sustained silence. Positions ‘1’ through to ‘F’ provide a range
of 8 to 120 seconds in 8-second increments.
The following table shows the silence threshold timing available:
SIL TIME Threshold
SIL TIME Threshold
0
1.5 seconds
8
64 seconds
1
8 seconds
9
72 seconds
2
16 seconds
A
80 seconds
3
24 seconds
B
88 seconds
4
32 seconds
C
96 seconds
5
40 seconds
D
104 seconds
6
48 seconds
E
112 seconds
7
56 seconds
F
120 seconds
Audio Monitoring
Audio monitoring is provided at the card edge with two miniature stereo jack sockets. The
left hand socket is connected to the Stereo 1 input signal and the right hand socket is
connected to the Stereo 2 input signal.
ADCA412 User Manual R2.1
21
30 October 2018
