Quantec Zombies 12xx Series, Руководство по эксплуатации

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Operation Guide Revision 3.7c
©1994 - 2003 Quantec® Tonstudiotechnik GmbH, Munich, Germany
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Glossary
GL is an abbreviation of global loop, the audio loop orientated towards the studio. It begins with a
an empty clock signal or a clock and audio signal somewhere in the studio as audio send, enters the
GL ZOMBIE input, leaves the ZOMBIE at the GL output and finally either arrives back as audio
return either at the device from which the original signal was sent, or another device, for example a
mixing console.
LL is an abbreviation of local loop, the audio loop orientated toward the device which should be
integrated fully into the studio. An empty clock signal or clock and audio signal leaves the ZOMBIE
LL output, enters the target device at its sending or recording input, leaves the target device at its
return or playback output, and finally enters the LL input of the ZOMBIE.
Frame, or better data frame, is a complete 64-bit data block of an audio sample, consisting of one
left and one right sample, the attached control and signaling bits, and the synchronization
preambles.
Frame skew is a delay to the frames resulting from finite propagation delay of real-world studio
devices. Referred to a »fresh« House Sync, equipment burdens the frame with a certain amount of
delay each time it transits a device. AES11 allows a frame skew of 5% of the sample period per
device. On the other hand, all inputs must tolerate frame skews of at least ±25%.
Genlock describes a situation where a device is fed with a clock signal extracted from the input
audio signal, rather than by a specific external clock signal. The syllable »gen...« comes from
»Generator«, so the term basically suggests a device generating its own clock signal. The term
originated in video technology and has since started to become widespread with reference to digital
audio.
House Sync is the central clock signal for a studio, e.g. word clock or an “empty” AES3 signal.
AES3 is an industry standard for two-channel transmission of linearly coded audio data using a
self-clocking code on a balanced twisted-pair line. In addition, there are two special data
transmission channels: the status channel (»Channel Status Bits«) and the user channel (»User
Bits«).
AES11 is an industry standard for synchronization of a digital recording studio based on AES3
hardware. There are two topologies: »Reference Clock« (star-type House Sync) and »Embedded
Clock« (genlock). Moreover, AES11 defines the requirements for clock accuracy, capture ranges of
PLLs, and parasitic propagation delays.
AES18 is an industry standard for transmitting control and signaling data using the AES3 user
channel. To block-synchronize the freely definable datagram lengths, a modified HDLC protocol is
specified. Also specified in AES18 is an access protocol to provide a fair allocation of the
transmission channel between all stations.
AES/EBU is, not completely accurately, a popular synonym for AES3.