Grass Valley MPEG Upgrade - Manual (Page 32)

MPEG Board Upgrade Installation
22 MPEG Board Upgrade Installation
In general, the video board in the lowest-numbered slot must provide the audio
clock signal to the to the first audio bank (and the second bank if the video board
has two inputs) on the ASPB. The video I/O board installed in the next
higher-numbered slot should provide the audio record clock signals for the next
audio banks, and so on until all four audio banks have their record clocks
connected.
For example, if you have two analog composite I/O video boards in slots J14 and
J15, the audio clock signal from the board in J14 should be connected to the first
and second audio record input clock signals on the ASPB while the signals from
J15 should be connected to the third and fourth connectors. See serial digital I/O
examples of audio clock cabling for one serial digital I/O board in Figure 7 on
page 23, for two boards in Figure 8 on page 25, and for four boards in Figure 9 on
page 27.
If your Profile unit only has one ASPB, you can connect only four record clocks
to it. If your disk recorder has two ASPBs, eight record clocks are available. If
your Profile unit has more than four video inputs, you should connect record
clocks from video inputs that might record video that is not genlocked to your
house reference, such as remote feeds from outside your facility. Any video inputs
that are not supplying a record clock to the ASPB should be locked to your house
reference, if audio is to be associated with those inputs. Otherwise, audio clock
errors could occur during recording.
The first cabling example shows the external audio clock and Sharcnet cabling
necessary for a single serial digital I/O board used with a single ASPB. The cable
connections are listed in Table 4 and shown in Figure 7.
Table 4. Cabling for a serial digital I/O board and an ASPB
Cable Type From Serial
Digital I/O
To ASPB
Sharcnet Sharcnet In Sharcnet Out 1
Sharcnet Sharcnet Out Sharcnet In 1
Audio clock Channel A Audio 1
Audio clock Channel B Audio 2