Midi - RME Audio Fireface UCX User Manual

Special Characteristics of the SPDIF Output
Apart from the audio data itself, digital signals in SPDIF or AES/EBU format have a header con-
taining channel status information. False channel status is a common cause of malfunction. The
Fireface UCX ignores the received header and creates a totally new one for the output signal.
The Fireface UCX new output header is optimized for largest compatibility with other digital
devices:
• 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz depending on the current
sample rate
• Audio use, Non-Audio
• No Copyright, Copy Permitted
• Format Consumer or Professional
• Category General, Generation not indicated
• 2-channel, No Emphasis
• Aux bits Audio Use
Professional AES/EBU equipment can be connected to the Fireface UCX thanks to its 'Profes-
sional' format option and a doubled output voltage. Output cables should have the same pinout
as those used for input (see above), but with a male XLR plug instead of a female one.
Note that most consumer HiFi equipment (with optical or phono SPDIF inputs) will only
accept signals in 'Consumer' format!
Therefore in SPDIF mode the optical output is fixed to Consumer status.

23.3 MIDI

Fireface UCX offers two MIDI I/Os on four 5-pin DIN sockets via an included breakout cable.
The MIDI ports are added to the system by the driver. Using MIDI capable software, these ports
can be accessed under the name Fireface MIDI. Using more than one Fireface, the operating
system adds a consecutive number to the port name, like Fireface MIDI (2) etc.
The MIDI ports support multi-client operation. A MIDI input signal can be received from several
programs at the same time. Even the MIDI output can be used by multiple programs simultane-
ously. However, due to the limited bandwidth of MIDI, this kind of application will often show
various problems.
Note: The MIDI input LEDs display any kind of MIDI activity, including MIDI Clock, MTC and
Active Sensing. The latter is sent by most keyboards every 0.3 seconds.
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User's Guide Fireface UCX © RME