GRASS VALLEY APEX -, Installation And Service Manual

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48 APEX — Installation and Service Manual
Section 2 — Planning Guide
Reference Connections
Each Apex chassis must have a video reference or an AES reference in order
for switches to occur on the proper audio frame boundary.
The Video reference can be used to synchronize AES audio. Dolby E oper-
ation requires use of a video reference. This video reference can be either
NTSC, PAL video, or black burst. The video reference input uses looping
75 Ohm BNC connectors; if the signal does not continue to another device
a 75 Ohm terminator must be installed.
Alternatively, an AES reference (AES3-1992
1
bit stream or SPDIF
1
bit
stream) that is used to synchronize AES audio in the facility can be con-
nected to the Apex. Two connectors are provided for this reference: a BNC
type for 75 Ohm cabling and a 9-pin D female type for 110 Ohm cabling.
(Pinouts for the D connectors are shown on
Figure 35 on page 87 .)
Note Only the 3.0 version of Standard Apex and the 2.0 version of the Apex Plus
support Video reference.
The “A” references are brought to Matrix Board A, and the “B” references
are brought to Matrix Board B. If redundant Matrix boards are installed, the
same reference must be presented to both REF A and REF B connectors, the
system will automatically operate the Matrix boards as a redundant pair.
For example, a video reference could be connected to Video Reference “A”
and looped to Video Reference B. If Matrix board “A” failed, then the
Matrix board B would become active. This same single video reference
should be selected for use on all input and output boards.
If necessary, each chassis can use separate, independent references.
Please refer to the following system examples, which are presented in order
of increasing complexity.
1.
See Glossary