Grass Valley NV7512 v.1.3 - Manual (Page 16)

6 Rev 1.3 • 10 Oct 08
1. Introduction
Signal Types and Rates
The following is a list of signal types and inter-mix options. In all cases, audio path delay does not
introduce any “lip sync” issues and can safely be ignored.
Mono Channels
The NV7512 routes AES signals internally as mono channels. The router can route individual chan-
nels independently or recombine channels to create new stereo signals. To perform switching, an
external AES reference signal must be connected to maintain synchronization.
AES signals are comprised of five parts: a preamble, left channel, channel status bits and right
channel. When received as a stereo signal, the signal is broken apart, separating out the left and
right channels to create two mono channels. The mono channels are then managed as separate sig-
nals within the router. The channel status bit and user bits are passed through. When the signal is
distributed as output, the preamble, channel status bit and user bits are added back to the left and
right channels to create a stereo signal.
When routed as a mono signal, individual left or right channels can be combined with other indi-
vidual channels and distributed as a new channel-pair combination (stereo signal). For example, a
live news report may capture the news reporter’s voice on the left channel and the background
noises on the right channel. By splitting the AES signal into its left channel and right channel, the
news reporter’s voice (left channel) can be paired with a different background noise (right channel).
There must be two channels for the signal to be regenerated as a single stereo output.
How mono signals are recombined and routed to outputs is determined by the router control sys-
tem.
Input Type Output Type Mix Options Delay
Analog Analog Analog input
and
analog output < 1.2 mS
Analog Digital Analog input
or
AES synchronous input
and
AES synchronous output ~658 µS
Digital Analog AES synchronous input
and
Analog output ~539 µS
Digital Digital AES synchronous input
and
AES synchronous output 104.2 µS