Lynx Studio LT-MADI - Manual (Page 17)

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7.3 Connector Types
MADI is typically carried on one of two connector and cable types, and both are supported by
the LT-MADI card. The older, original method is coaxial cable with BNC connectors. The LT-
MADI requires 75 Ohm coaxial cable. Cables of this sort are inexpensive and easily procurable.
The alternative, more typical with newer MADI devices, uses SC-Type Optical connections with
network fiber optic cables. There are a number of benefits to this connection type including
markedly less jitter on the digital signal. One of the biggest differences between the two
connection types is maximum cable length. Cable runs of up to 2000 meters are possible with the
fiber optic connection, whereas coaxial has a maximum cable length of 100 meters.
Two types of glass fiber optic cables can be used:
• Cables with an internal diameter of 50 µm and an external diameter of 125 µm are
typically orange and referred to as 50/125 Network Cables.
• Cables with an internal diameter of 62.5 µm and an external diameter of 125 µm are
typically blue and referred to as 62.5/125 Network Cables.
Signals passing to the LT-MADI outputs are mirrored to both the coaxial and fiber optic ports.
Potentially, both can be connected at the same time in cases where it is useful to have duplicate
streams sent to different devices for recording or monitoring.
For MADI input signals, the hardware supports only using either the optical or coaxial ports, but
not both simultaneously. The MADI receiver auto-detects which connection has a valid MADI
signal, and selects that as the default input port. If both connections contain a valid MADI signal,
then priority is given to the fiber optic port.
Tips: LED1 being ON indicates that there is a valid MADI signal on an input port, otherwise, if
the incoming MADI signal is invalid, LED1 will blink. LED2 being ON indicates that both
MADI output ports are enabled and are passing MADI data.
7.4 Configuring Multiple Auroras
The LT-MADI was designed so that up to four Auroras could be daisy-chained through a single
MADI connection. This allows great flexibility in creating a high-channel count system that is
simple to manage and use. Any combination of Aurora 16s and/or Aurora 8s can be combined to
a channel maximum of 64-channels.
As described earlier, each MADI connection carries up to 64 channels divided into 16-channel
clusters. Aurora I/Os occupy these clusters based on several factors:
• Aurora Type (8 or 16)
• Channel Mode (16 or 32 – Pertinent to Aurora 16 only, see Section 7.2.)
• Sample Rate (1X – 44.1/48kHz, 2X – 88.2/96kHz, or 4X – 176.4/192kHz)
• Unit ID settings (LT-MADI Switches SW1 – SW2)