Grass Valley 8900GEN-SM - Manual (Page 37)

8900GEN-SM — Instruction Manual 37
8900GEN-SM Applications
Using Independent Frame Bus References
As shown in Figure 15 , another use for utilizing the dual frame bus func-
tion is to distribute two completely different references on independent
frame buses. The Primary Ref Bus 1 could be an NTSC Color Black and the
Secondary Ref Bus 2, an HD standard such as 1080i 59.94, where a more
precise reference is needed to time the HD signals.
Module Placement and Cabling For Independent Frame Buses
One reference type, such as NTSC Color Black, is connected to the corre-
sponding rear Genlock Loop of a host module with an 8900GEN-SM sub-
module in slot 1. A different reference such as a 1080i 59.95 frame rate, is
connected to the rear Genlock Loop of a host module with an 8900GEN-SM
submodule in slot 3. The host module circuit boards must be jumpered to
output the frame buses to the modules in the frame.
On modules in the frame with NTSC input signals that require the NTSC
timing reference, the Ref 1 (Primary) selection would be selected as the
Output Timing source on each module’s System Config web page. On
modules requiring HD 1080i 59.94, Ref 2 (Secondary) would be selected as
the Output Timing source on each module’s System Config web page.
In this case, redundant operation is not needed as switching to the other
reference would cause major timing errors. For this configuration, the
Primary and Secondary sources on the System Config web pages should be
set as the same.
Figure 15. Independent Frame Bus Genlock Timing Sources
8488_02
Frame Bus 1 (NTSC Color Black)
Slot 1 Slot 3 HD SD SD SD SD SD HD HD
Frame Bus 2 (1080i 59.94)
NTSC Color
Black In
1080i
59.94