RME M-16 AD [23/57] Digital inputs outputs

User’s Guide M-32 AD © RME

11. Digital Inputs / Outputs

11.1 ADAT Optical

The M-32 AD has an optical ADAT input for optional clock synchronisation, in case word clock

or MADI signal are not available. Included audio data are not processed.

Furthermore the unit has 4 optical ADAT outputs. When used with sample rates up to 48 kHz 32

output channels are provided (8 per port). Higher sample rates are transmitted by Sample Mul-

tiplexing (S/MUX). Therefore the channel count decreases to 16 channels at Double Speed and

8 channels at Quad Speed.

The ADAT outputs are available up to 192 kHz in parallel to the MADI output, with the above

channel limitation.

A usual TOSLINK cable is sufficient for connection.

11.2 MADI Input

Both MADI inputs are located on the rear of the M-32 AD.

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 ADI-6432 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 ADI-6432 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 is used as optional clock source (Clock section, MADI) as well as a through

input. Since a M-32 AD uses only 32 channels, it by-passes the remaining 32 channels.

The MADI input serves as optional external clock source, but also as MADI pass-through input.

Since the M-32 AD uses only 32 channels of the MADI signal, unused channels of the input

signal are fed through to the output.

This technique is used to cascade M-32 ADs serially. Incoming MADI data is passed through

unchanged, but 32 channels are replaced by the data of the M-32 AD. This way up to two M-32

AD (four M-16 AD) can be cabled serially via MADI. At the output of the second unit 64 chan-

nels M-32 AD are available on one line. The used 32-channel block is set on every unit’s front

plate via the MADI OUT key.