MI_STAR_EN.doc
SR Installation Manual EN
Indice : C
03/05/2019
7 / 15
ERECA SAS 75 rue d'Orgemont, 95210 SAINT GRATIEN France
Tel +33 1 39 89 76 23 www.ereca.fr
1.2.4 Digital AUDIO
Digital audio is available on true 75 Ohms BNC sockets.
The total capacity of the stage racer is 4 simultaneous bidirectional AES signals. Thru the web server the
AES 3 and 4 could be turned to MADI, Respectively Madi IN on port 3 and Madi OUT on port 4.
Caution: Avoid connecting 50Ohms plugs it will damage the socket central pin causing costly repair
especially it this one is on the lower part of the connector side.
1.2.4.1 Bidirectional AES
Each AES port is internally equipped with a 2-4 wire converter connected to a fully bidirectional transmit
path to the remote stage racer.
This allow to interconnect talkback panels working in a bidirectional manner on one 75 Ohms coax. The
ports still can be used without configuration to transport unidirectional signal, no setup needed for channel
direction.
Note1: For the internal 2-4 wire converter correct behavior the source/terminal impedance of the machine
connected to the AES ports must be 75 Ohms.
Note2: The bidirectional function of the device constraint the design specially to provide an accurate AES
activity led display and avoid signal loop if port impedance is not 75 ohms. The internal FPGA seeks for
AES3 audio XYZ preamble at 48 KHz to light the corresponding AES Led and enable transmission in this
direction. Basically, the equipment is able to transmit 44.1 and 48 KHz audio, in the other case the detection
scheme will prevent transmission. Please ask for a product evolution if this stuck your application.
1.2.4.2 MADI transmission
When selected through the web server, MADI Is transmitted instead of 2 AES signals. The MADI signal
applied to port 3 of a device is output on port 4 of the remote equipment.
The MADI clock information is transmitted along the MADI signal, at receiving side the original clock is
precisely regenerated and MADI data delivered accordingly to this clock. Thus, the transmission is clock
conservative, so if the MADI machine used is able to synchronize on the MADI payload, you do not have to
carry a parallel wordclock signal thru another channel of the stage racer.
The MADI output VCXO capture range is +/- 100 ppm.
Note: If more MADI signals are needed it can be passed thru the Video cha nnels by simply selecting the
right channel direction and bypassing the corresponding reclocker.