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Zodiak Installation and Service Manual
Section 3 — Configuration
Tally Configuration
The Tally menus are used to configure the tally system. There are multiple
tally calculators, three different tally calculation methods, and user assign-
ment of tally relays. The results of the tally calculators are applied to the
tally relays in the Video Frame, and those relays can control external tally
lights. The menu set also allows the user to map Engineering sources to the
tally relays. Each Video Frame provides 32 tally relay outputs, which are
recalculated and refreshed every field.
About Tally Systems
In general, a tally system identifies which sources to the switcher con-
tribute to the final picture at a selected point in the video chain. The identi-
fication is communicated by activating relays in the video 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 video 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 pro-
grammable 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 cal-
culator 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 speci-
fied 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
this virtual output is not on air.
The Output tally calculator indicates which sources contribute to desig-
nated outputs. For example, a 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 indi-
cate 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.
