Meyer Sound Galileo GALAXY 408, Руководство пользователя

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GALILEO GALAXY USER GUIDE
59
APPENDIX B: CLOCKING
MEDIA CLOCK FOR A SINGLE GALAXY PROCESSOR
NOTE: “Media Clock” is the common terminology used in the Milan specification. Within the GALAXY
processor Settings: Input and Output tab, the Media Clock choice is selected under the “System Clock: Clock
Mode” pull-down menu.
The GALAXY 816 processor and the GALAXY 408 processor offer four clock options for the media clock: GALAXY Internal
Clock, CRF Clock Stream, AAF Audio Stream Clock, and AES3 Clock (the first four choices shown in Figure 30, GALAXY
System Clock Selection box).
The GALAXY 816-AES3 processor offers the same four plus a Word Clock of 48 or 96 kHz via an additional BNC
connector.The GALAXY 816-AES3 processor can be synchronized to an external source depending on the digital input
selection: AES3 offers discrete values in the range from 20–216 kHz (see “Input Sample Rates” on page 62).
NOTE: For an AES3 input to be selectable in the System Clock, Clock Mode drop-down, it must be
synchronous to the GALAXY internal clock (48 kHz or 96 kHz ±100 ppm). Synchronous means the external
source and the GALAXY processor have a common clock (to within ±100 ppm). A common clock with the
sender of data is necessary for any device to accurately interpret the binary data it receives. If the device clocks are
asynchronous—any of the allowable AES input clock rates NOT equal to 48 kHz or 96 kHz, and thus not common
with the GALAXY internal clock—they cannot be used as a system clock. Furthermore, any audio input associated
with this asynchronous clock must pass through the Asynchronous Sample Rate Converter (ASRC) to make that
input data synchronous, or accurately aligned to the GALAXY processor internal processing clock.
Figure 30: GALAXY Processor Clocking Scheme
Milan AVB Media
Clock Selection
AES3 Input
Selection
AES in Clock = 20 to 216 kHz
Validity
Check
ASRC*
AVB Output
(48/96 kHz)
AES3 Output
Settings
*GALAXY 816-AES3 only
AES Output=
44.1 kHz
48.0 kHz
88.2 kHz
96.0 kHz
176.4 kHz
192.0 kHz
ASRC
GALAXY System Clock Selection
AES3 Output Clock Select*
SSRC
XLR
RJ45
Milan AVB
Milan AVB
AES3
AES3
Outputs
1-16
Word Clock In*
BNC
GALAXY
Internal Clock
AAF Audio
AES3 Clock
AES3
Clock
Media
Clock
Word Clock
Word
Clock
CRF Clock
Stream
SSRC = Synchronous Sample Rate Converter (48 or 96 kHz)
*ASRC = Asynchronous Sample Rate Converter (If on, this input CANNOT be the media clock).
If System Clock is selected as Word Clock or AES input and signal is outside of 100 ppm range, GALAXY will automatically switch back to Internal Clock.
SYNC CLOCK LED will be a red color and Error code will display on the front panel.
*GALAXY 816-AES3 only