Installation & Operation Manual TCC70XS
Page 66
This method allows a time transfer only for up
–
counting read values
. A “reverse” or “still”
time code will be ignored. However, the generator takes the read time values only if the
time difference between reader and generator time exceeds an adjustable threshold. The
“Diff Cont.” and the “Diff Stop”
methods differ in case no reader values are present: with
“Diff Cont.”
the generator continues to count the time on its own (continuous Jam Sync
without flywheel option), with
“Diff Stop” the generator stops counting after a programmed
number of frames (programmable flying wheel).
This method sets the generator time equal to the read time at the beginning
–
for example
with the start of a video tape. Later dropouts or phase shifting will not lead to a discontinu-
ous time code output. Each time
a difference of ≥ threshold occurs
, for example after
stopping and restarting the tape, the generator is automatically locked to this new read
time code.
This method takes
the value of the flywheel (“Wheel”) as threshold for the difference. The
allowed range of values is 2
–
20 frames. If the current value does not lie within this range
the threshold will automatically be set to 4 frames.
Please notice the following remarks concerning this method and the setting of the
threshold:
If a time difference greater than the threshold has been detected, the generator accepts the
reader values for the next two seconds to get in sync. During this period the incoming time
code should stabilize (for example a recorder should reach the normal play speed). If
during this period no synchronization has been reached, the generated values compared to
the incoming time code now can have any difference up to the threshold value.
If there is no synchronization between the incoming time code and the generated time
code, a continuous drift against each other will take place and a time difference will built
up. If the difference exceeds the threshold, a "hard" correction takes place. With the
"Continuous" Jam Sync function you would have a one frame jump quiet often in this case,
with the "Diff" Jam Sync function you would have a jump of the size of the threshold rarely.
However, the more briefly you choose the production time, the more highly the probability
for an error free re
–
generation, because the difference will not reach the threshold.
Zero Frame
With this method, the generator accepts the reader values only if the frame count of the
reader values equals to 00. Even if there are different frame rates of reader and generator
time code, both time codes will be aligned exactly at the start of each second.
This method should be selected for a frame rate conversion. In case of a video format
conversion (e.g. PAL to NTSC or vice versa) the original time code should be connected to
the time code input and the converted video should be connected to the video input of
TCC70XS. Thus, the converted time code will be synchronised to the converted video.
Format
Converter
Video PAL
Time Code PAL
Video NTSC
Sync
TC In
TC Out
Time Code NTSC
Jam-Sync
"Zero Frame"
Format
Converter
Video NTSC
Time Code NTSC
Video PAL
Sync
TC In
TC Out
Time Code PAL
Jam-Sync
"Zero Frame"