Multi-Client Operation; Digital Recording; Clock Modes - Synchronization - RME Audio Digiface Ravenna User Manual

8.4 Multi-client Operation

RME audio interfaces support multi-client operation. Several programs can be used at the same
time. The formats ASIO and WDM can even be used on the same playback channels simultane-
ously. As WDM uses a real-time sample rate conversion (ASIO does not), all active ASIO software
has to use the same sample rate.
However, a better overview is maintained by using the channels exclusively. This is no limitation
at all, because TotalMix allows for any output routing, and therefore a playback of multiple soft-
ware on the same hardware outputs.
Inputs can be used from an unlimited number of WDM and ASIO software at the same time, as
the driver simply sends the data to all applications simultaneously.
RME's sophisticated tool DIGICheck is an exception to this rule. It operates like an ASIO host,
using a special technique to access playback channels directly. Therefore DIGICheck is able to
analyse and display playback data from any software, no matter which format it uses.

8.5 Digital Recording

Unlike analog soundcards which produce empty wave files (or noise) when no input signal is
present, digital interfaces always need a valid input signal to start recording. Taking this into ac-
count, RME added a comprehensive I/O signal status display to the Digiface Ravenna, showing
sample frequency, lock and sync status in the Settings dialog, and a status LED directly at the
unit.
The sample frequency shown in the Settings dialog is useful as a quick display of the current
configuration of the unit and the connected external equipment. If no sample frequency is recog-
nized, it will read 'No Lock'.
This way, configuring any suitable audio application for digital recording is simple. After connec-
tion the Digiface Ravenna displays the current and external sample frequency. This parameter
can then be changed in the application's audio attributes (or similar) dialog.

8.6 Clock Modes - Synchronization

In the digital world, a device must be either Master (clock source) or Slave (clock receiver). When-
ever several devices are linked within a system, there must always be a single master clock.
! A digital system can only have one master! If the Digiface Ravenna's clock mode is set to
'Internal', all other devices must be set to 'Slave'.
This also applies in a network. Typically, a single device is defined as a clock master (Grand
Clock), controlling both the network and all connected devices. The Digiface Ravenna can be
synchronized as slave over incoming network streams, or an attached word clock, or MADI signal.
As master, it uses its internal clock, becoming the clock master of the entire network.
RME's exclusive SyncCheck technology (first implemented in the Hammerfall) enables an easy
to use check and display of the current clock status. Input Status indicates whether there is a valid
signal (Lock, No Lock) for the coaxial input, or if there is a valid and synchronous signal (Sync).
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User's Guide Digiface Ravenna © RME