M-AUDIO Delta RBUS - Manual (Page 28)

audio software application to this same sample rate or else the
application will display an error message.
NOTE: When R-BUS PCI is the master clock source, the
digital monitor mixer will run at the sample rate received at
the R-BUS internal sync connector. Since frequency
response and sample rate are directly related, the mixer
frequency response will be directly related to the sample
rate of the S/PDIF input data.
MULTITRACK DRIVER DEVICES
The Delta R-BUS drivers intelligently synchronize the beginning of
recording and playback across all audio devices on the board. When
using application software that is capable of using multiple channels
simultaneously, select "Single and In-Sync" to ensure that all audio
channels will begin playback and/or recording at the same time.
Otherwise select "Independent" to allow the audio channels to play
independently – this setting may be desirable if more than one
application needs to access the Delta R-BUS simultaneously.
The selection “Multi-card Sync” will remain grayed out until a second
Delta PCI card (of which there are a variety) is installed in the system.
When you wish to synchronize two (or more, up to four) Delta cards,
select Multi-card Sync on the second and successive cards. This is done to
ensure that playback starts simultaneously on multiple cards.
Then, all cards must be synchronized via wordclock in some fashion. If
you have multiple Delta R-BUS cards, you can synchronize them using
the internal sync connectors on the PCI card. Output of the first, or
“master” card connects to the input of the second card, then the sync out
of the second card connects to the third, etc. The master card may derive
its clock from internal or external clocks, while all subsequent cards
should be set to “R-BUS PCI” as their clock source.
You may also synchronize via S/PDIF. Select S/PDIF as your master
clock on the second and subsequent cards, and connect the S/PDIF
output of the first card to the S/PDIF input of the second card, etc. These
settings ensure that when the application goes into record or playback, it
waits until all audio ports are open before it commences with recording
or playback of audio.
DMA BUFFER SIZES
This section specifies the amount of system memory dedicated to digital
audio buffering. Setting a buffer size that is too small may result in clicks
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