Digital Inputs / Outputs; Adat Optical; Madi Input - RME Audio M-16 DA User Manual

11. Digital Inputs / Outputs

11.1 ADAT Optical

The M-32 DA has four optical ADAT inputs. When used with sample rates up to 48 kHz 32 input
channels are provided (8 per port). Higher sample rates are transmitted by Sample Multiplexing
(S/MUX). Therefore the channel count decreases to 16 channels at Double Speed and 8 chan-
nels at Quad Speed.
With signals encoded as S/MUX, the Clock Section (STATE) has to be switched into DS mode
manually, depending on the current application. Each port carries the data of 4 channels only.
With signals encoded as S/MUX4, the Clock Section (STATE) has to be switched into QS mode
manually, depending on the current application. Each port carries the data of 2 channels only.
A usual TOSLINK cable is sufficient for connection.

11.2 MADI Input

Both MADI inputs are located on the rear of the M-32 DA.
The BNC input's ground-free design is built according to AES10-1991. The input's impedance is
75 Ohm. It will operate without error from about 180 mVpp.
The optical input uses a FDDI (ISO/IEC 9413-3) compatible optical module, according to
AES10-1991. More information can be found in chapter 16.6, MADI Basics.
The M-32 DA includes automatic input selection. In case the current input signal fails, the unit
switches to the other input immediately. This mode, called redundancy mode, offers improved
safety against errors on the transmission line. Switching the inputs is done in about one second.
The unit displays redundancy operation by a blinking LED of the original input, while the input
LED of the currently active input will be lit constantly.
The MADI input serves not only as audio source and optional external clock source, but also as
MADI pass-through input. Since the M-32 DA converts only 32 channels of the MADI signal, all
channels of the input signal are passed to the output. Additional M-32 DA or M-16 DA can be
connected serially to convert the remaining signals, in any combination, up to a maximum of 64
channels: One M-32 DA with one or two M-16 DA or up to four M-16 DA.
As MADI covers long distances up to 2 km, even the same channels can be converted in sev-
eral different (electrically separated) locations, with comfortable and unambiguous front panel
channel selection.
The currently used 16- or 32-channel block is set on every unit's front plate via the MADI IN
key.
User's Guide M-32 DA © RME
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