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INSTALLATION
2.10.2. Rank Cintel Film Frame Pulse
In addition to the bi-phase connections, a film frame pulse is required. This
active low pulse occurs when a new film frame starts in the video output,
while the telecine is in normal play speed. The 4025 uses the film frame
pulse to lock its timecode output to the correct telecine pulldown sequence
during the transfer.
Some telecines, such as Rank Cintel MKIIIC Digiscan 3 models, continue
the frame pulse in an unbroken sequence even when they are in shuttle
modes. When used with these telecines, the 4025 can be configured for
AUTO rate detect. Changes in transfer rates by the telecine operator are
automatically detected when the telecine is in still. (See sections 3.4.4 or
3.10.9 for information on how to select auto rate detect mode). Other
telecines, such as Rank Cintel 4:2:2 Digiscan 4 and URSA models do not
maintain coherent film frame pulse sequences in shuttle modes. When
used with these telecines, the 4025 must be manually set to the correct
transfer rate to accurately track the film/timecode relationship.
The actual DC voltage level of the film frame pulse is not critical as long as
a 1 volt peak to peak minimum signal is applied. The film frame pulse is
sampled once per video field approximately mid-field.
Figure 2-10 shows the timing requirements for the Rank Cintel frame pulse.
The frame pulse must be low at the trailing end of vertical sync and return
high again before the end of the field.
Connection of a Film frame pulse is required even with PAL video to permit
the 4025 to distinguish the difference between the field 1 and field 2
dominant pull downs.
It is essential that the 4025 be connected to the correct FILM FRAME pulse
from the telecine. Generally this pulse is labelled "FRAME PULSE" on the
Rank Telecines and is found on the rear of the Digiscan electronics rack.
Figure 2-10 shows some specifications of the expected Frame Pulse into
the 4025.
This should allow you to locate the appropriate signal,
regardless of the labelling on your telecine. The Rank telecine manuals or
Rank technical support personnel may also be able to assist you.
The telecine type item of the Engineering toolbox hardware menu controls
whether standard Rank Cintel, URSA Gold or BTS pulldown pulse is
expected. The telecine type should be set to the Rank or URSA Gold
settings accordingly to accept the Rank Cintel style FRAME pulse input
from the "FRAME BNC connector on rear panel. (See section 3.6.4)
If the right hand LED on the 615 module (center card behind the front
panel) is blinking, or dim, or flickering rapidly, that is an indication that the
Frame Pulse input is not satisfactory.
Model 4025 Film Footage Encoder Manual
Page 2-15
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