Crown Audio DCi Series – Network Input Models - Manual (Page 32)

DriveCore Install Network Series Power Amplifiers
Operation Manual page 32
BLU link
BLU link is an audio bus found on the DriveCore Install Network amplifier series. It carries 256 channels of audio at 48kHz, and 128 channels at 96kHz, both at 24bit. When
connected in a loop, it has redundancy, allowing any one BLU link cable to break while still maintaining audio.
BLU link Specification
• Based on Gigabit Ethernet technology
• 100m over CAT5e cable between each point.
• >100m using fibre converters.
• 256 Channels at 48KHz
• 128 Channels at 96KHz
• Bus-like architecture. Audio transmitted on a channel is available at all other devices on the network automatically.
• Wired in a loop for redundancy
• Recovers from a single cable break
Hardware Configuration
On the rear of the BLU link devices there are two BLU link ports. One is the BLU link In, and the other BLU link Out. Devices are connected together by wiring Out to In on all
of the devices within your BLU link network, making sure that the loop is complete so that there are no empty BLU link ports. You should not connect the BLU link ports to
anything other than BLU link ports. BLU link will not function if you try to connect the BLU link to an Ethernet switch for example.
Fault Tolerance
The network is capable of a degree of fault tolerance due to the fact that each device receives the same audio from 2 other devices. If a cable is broken the devices which are
no longer connected will detect the cable break. One device will detect that its 'In' port is unconnected and the other will detect that its 'Out' port is undetected.
NOTE: when the cable is broken, the audio takes longer to reach its destination than before. This added delay is not compensated for in any way, but is a side-effect of the
way the fault tolerance works.
Mastership
The BLU link network requires one device on the ring to act as master for the whole ring. The master will provide the clock for all the other devices on the ring. This means
that the whole ring is synchronised to a single audio clock.
In certain cases, it is possible to utilize devices of more than one Ethernet transport type (AVB, CobraNet™, or Dante) connected within the same BLU link ring. In other
words, if you’re careful, you can design a Harman system which actually includes more than two transports. For example, it’s possible for a Harman system to have
CobraNet audio being converted to BLU link audio (BLU-800 and BLU-320 both have the ability to “bridge” CobraNet to/from BLU link), which is then converted to Dante
audio (BLU-806 and BLU-326 both have the ability to “bridge” BLU link to/from Dante). It all depends on a given transport’s ability to “slave” (AKA “re-clock”) to a clock
being generated by a separate transport.
Can it be “slaved” to the clock of another transport?
AVB No
BLU link Yes
CobraNet No
Dante Yes
The previous chart has critical implications on system-design when combining two or more transports. Any system based on Soundweb London (including Architectural
Media Systems) supports the following five multi-transport combinations:
• BLU link + AVB (AVB provides the clock)
• BLU link + CobraNet (CobraNet provides the clock)
• BLU link + Dante (either BLU link or Dante provides the clock)
• BLU link + Dante + AVB (AVB provides the clock)
BLU Link