9
In single wire operation AES outputs 1-4 are copied by AES outputs 5-8 providing two sets of (8-channel) digital
outputs. In dual wire mode, AES outputs 1-4 carry audio channels 1-4 and AES outputs 5-8 carry audio chan-
nels 5-8.
Please see the digital output diagram on page 22.
The A/D converter module also has an additional set of outputs. These can be either 4 x AES3id BNC outputs or
2 x ADAT Lightpipe outputs – (the configuration is determined at time of purchase). The AES3id outputs each
provide 2 channels of audio data in single wire mode or 1 channel of audio data in dual-wire mode. The ADAT
lightpipe outputs provide 8 channels of audio data on each (at base rate). At dual rates the ADAT S-MUX is en-
abled and channels 1-4 are available on ADAT output 1, while channels 5-8 are transmitted on ADAT output 2.
Quad sample rates are not supported over the ADAT interface.
AES3-id output connector configuration
AES3id connector
Audio channels 1-wire mode
Audio channels 2-wire mode
1
1-2
1
2
3-4
2
3
5-6
3
4
7-8
4
ADAT output connector configuration
ADAT connector
Audio channels Fs = 44.1-48kHz Audio channels Fs = 88.2-96kHz (S-MUX)
Upper
1-8
1-4
Lower
1-8
5-8
figure 2 / digital output configuration
DiGital clock connectionS
The m802 features an external clock input and clock output for syncronization to external clock sources. The
clock input BNC connector can accept a WORDCLOCK signal running at the selected sample rate or a AVID Pro
Tools® LOOPSYNC signal. For optimal performance when using the external clock connection, the m802 must
be connected directly to a 75 Ohm clock source. The external clock input is terminated to 75 ohms within the
m802 and thus should not be terminated elsewhere. The clock output connector signal can be derived from two
different sources, either a buffered copy of the incoming clock signal on the wordclock input connector, or the
internally generated WORDCLOCK.
Control Data Connections
preaMplifier Unit
m802 preamplifiers with serial number P802490 and above are now equipped with RS-485/RS-422 serial ports.
These units also contain the original
I
2
C
serial ports and are backwards compatible with previous m802 systems.
Note that
I
2
C
cannot be used in the same system where RS-485 / RS-422 is being used.
RS-485 is a bi-directional serial bus that can be configured in the same manner as the original
I
2
C
bus. RS-422 is
not bi directional but instead requires a wire for TX and a wire for RX. RS-422 can be used when interfacing with
equipment that requires separate RX and TX signals. As well, RS-422 can be readily converted to RS-232 with
widely available converters. The m802 firmware comes set from the factory with the RS-485/RS-422 port set for
RS-485 operation. If RS-422 operation is required then do the following:
1.
Hold the “SETUP” push-button on the front panel while turning the power on.
2.
Upon releasing the “SETUP” the m802 screen will display the current function of the RS-485 / RS-422
port.
