Compact Infinity Core
Compact Infinity Core 1
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Document generated: 13.06.18
2.5
Clocking concept of Infinity Core
The Sync source of the Infinity Core is always provided by a D23m frame.
The Sync signal of the D23m system is etiher internally generated by one of
the D23m frames, or an external sync signal is connected to one of the D23m
frames. The sync signal is then transmitted to the core via A-Link. All other
frames will be synced from the core via their audio interface (MADI or A-
Link).
The D23m system is able to connect to external sync sources to be synchro-
nised. Following sync sources can be used:
• Video
• Word Clock
• AES/EBU
• A-Link (main or redundant)
For Video 50 Hz, 59.94 Hz, and 60 Hz are supported. For all other sync sources
48 kHz, 96 kHz, 44.1 kHz and 88.2 kHz are supported.
An automatic process is employed to ‘look’ for the best possible sync source.
This process has the following rules :
1. External Clocks have higher priorities then internal clocks.
2. The priorities of the external sync signals are in this order :
1. Video reference, 2. Word clock, 3. AES/EBU 4. A-Link
3. The lowest A-Link portnumber (on the core) has the highest priority.
4. Once a switchover to a different sync source has occured, the system
will automatically switch back to the original source, as soon as this sync
signal is restored.
If the D23m system consists of multiple frames and a redundant Infinity Core
system, the above process provides an audio clock redundancy. If the D23m
frame which is the sync source, fails, the system will switch over to the next
possible D23m frame that can be the sync master.
2.6
Redundancy
The redundancy concept of the Infinity Core
closely interacts with the redun-
dancy of the D23m I/O system :
The D23m host card (A-Link HD card) offers two A-Link ports, main and
redundant with automatic switching - the D23m frame switches automatically
to the redundant connection, in case the main connection fails.
A-L
ink Quality of Service
Every A-Link carries its Qualtiy of Service indication, which is depending
on the state of the source that generates the A-Link signal.
Looking at this QoS, the D23m system can decide to switch from the main
A-Link to the redundant A-Link signal.
QoS is taking into account the following criterias of the source that generates
the A-Link signal :
