GRASS VALLEY KARRERA, Installation & Service Manual

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Installation & Service Manual
175
Switcher Relay Tally Configuration
Switcher Relay Tally Configuration
The GV K-Frame XP Switcher Tally menus are used to configure tally system relays. These
menus include multiple relay tally calculators, three different relay tally calculation
methods, and user assignment of tally relays. The results of the relay tally calculators are
applied to the tally relays on the GPI/Relay Tally connectors on the rear of the Video
Processor. Those relays can control external relay tally lights. The Switcher Relay Tally menus
also allow the user to map Engineering Sources to the tally relays. Up to 96 tally relay
outputs are available on a Video Processor, 24 for each installed Controller or M/E board.
Relay tally is recalculated and refreshed every field.
Note:
Relay tally Contribution is an alternative electronically mechanism
that can be assigned to a K-Frame Video Processor serial port. Refer to the
separate Grass Valley Switcher Protocols Manual for technical information.
About Relay Tally Systems
In general, a GV K-Frame XP tally system identifies which sources to the switcher contribute
to the final picture at a selected point in the video chain. The identification is
communicated by activating relays in the Video Processor Frame. The method by which the
sources are determined is called the tally calculation.
The tally calculation begins at a point in the video path and then traces the path of the
signals upstream to their original video (and key) sources. The state of the switcher affects
tally. For example, tally on a true clean feed only includes sources that contribute to the
main output, but tally on a programmable clean feed can include sources that do not
contribute to the main output.
When configuring a tally calculation, the user chooses the starting video path point (called
a tributary) to trace back to its origin. The main On Air tally video output point is Pgm-Pst
PGM A, but Pgm-Pst PGM B, Pgm-Pst C, and Pgm-Pst D are included in case these alternate
programmable clean feed outputs have keys (or utility buses) that don't contribute to the
PGM A output.
The On Air tally calculations are essential for switcher operation. (One calculator is reserved
for On Air.) This tally calculation forms the basis for On Air indication (panel, camera tally
lights, etc.), and other functions such as external device Auto Start, Off Air Advance, or
router protections. On Air tally calculations normally start at the Pgm-Pst PGM A-D outputs.
User tally calculations can be used for purposes other than On Air tally. These tally
calculations still trace the video path up stream from the specified points in the video path,
but the starting point does not necessarily have to be a program output. For example, a
Look Ahead tally begins at the Pgm-Pst Look Ahead Preview (LAP). When a transition is not
in progress the source feeding the PVW is not on air.
The Output tally calculator indicates which sources contribute to designated outputs. For
example, an M/E Iso tally is a user configured Output tally set up to begin at an M/E’s PGM A,
B, C and D. The tally would indicate what contributes to the M/E's program outputs but not
anything down stream of it. The tally would be the same whether or not the M/E was On Air.
The Look Ahead tally calculator indicates which sources will be on air if a main transition is
performed on the selected level. One way this can be used is for a second set of tally lamps
on a camera to alert the camera operator that his camera is next to be taken on air. Many
control room monitor walls also include a secondary tally