10
AES-3 Digital Audio Interface Card
Switches and Connections
Important: You must remove the card from the frame in
order to change any configuration switch settings.
DIP Switches
DIP Switch 1
Off: (Default) 16 bit audio is enabled. The card can
accept incoming audio up to 24 bit format. The
card transmits outgoing audio at 16 bit format.
On: 24 bit audio is enabled.The card can accept
incoming audio up to 24 bit format.The card
transmits outgoing audio at 24 bit format.
Description: Accepts and transmits audio at different
resolutions: 16 bit and 24 bit. Higher resolution results in
higherqualityof sound.
DIP Switch 2...................................unused
DIP Switch 3...................................unused
DIP Switch 4
Off: (Default)The AES-3 card monitors the
validity bit in the incoming stream and mutes
the incoming AES stream if the validity bit is
set.
On: The AES-3 card ignores the validity bit in the
incomingstream.
Description: Switch 4 control whether or not the
validity bit in the incoming AES stream is monitored and
actedupon.
DIP Switch 5:
Off: (Default) Monitors three types of minor
receiver errors and mutes the incoming audio
stream if at least five errors occur in any
200mstime window.
Note: The AES-3 card will unmute the incoming
audio if none of these errors have occurred for at
least 80ms.
On: Ignoresminor receivererrors. Ifthereare
adverse line conditions such that there are
repeated minor errors, the user may want
to ignore these errors and allow the audio to
passunmuted.
Description: There are three types of receiver errors
that can occur due to line conditions or clock problems:
Confidenceerrors
: the clock is suspect.
BI-Phase
Encoding errors:
thebi-phase encoding
ruleshavebeen broken.
Parity Errors
: an incorrect number of
transitions per frame
was detected.
DIP Switch 6:
Off: The AES-3 card monitors the non-audio
indicator bit in the incoming AES stream and
mutes the audio if the bit is set.
On: The AES-3 card ignores the non-audio
indicator bit in the incoming AES stream.
Description: The non-audio indicator bit is contained in the
incoming AES stream and indicates whether or not the AES
data can be interpreted as audio. If the switch is set to ON, the
non-audioindicatorbitisignored.
DIP Switch 7:
Off: The AES-3 card mutes the incoming audio on loss of
PLL and/or SRC lock, and will reset the AES chip
associated with that channel pair if either lock
remains unachieved for at least two seconds.
On: The AES-3 card will not reset the AES chip with
continued loss of PLL and SRC lock, and will not
mute the incoming audio when the SRC is unlocked.
It will always mute the incoming audio when the PLL
is unlocked.
Description: In normal operation, the AES-3 card attempts to
achieve PLL and SRC lock on the incoming AES stream. If a
lock cannot be achieved within two seconds, the card resets the
chip associated with the AES channel pair.
Note: It is possible there is no input stream connected to the
card, so no PLL or SRC lock will ever be achieved. In this case,
resetting the AES chip is not recommended because any AES
output stream from that card using that chip is interrupted.
If an AES output is being used and the corresponding AES input
is not being used, the user can prevent the AES-3 card from
resetting the AES chip to achieve PLL/ SRC lock
If an AES-3 chip is being re-initialized because of continued PLL
or SRC unlock, the Fail LED will flash ON for roughly a half
second every 2-3 seconds.
DIP Switch 8:
WARNING
:DIP switch 8 should always be left in the OFF
position. It is reserved for debugging and can have unintended
consequences.
Figure 3. AES-3 DIP Switch panel - Switch 1
