User manual

Front Panel Operations Imagestore HDTV User Manual
Page 136 Miranda Technologies Ltd
Select Reference
Use this option to select the appropriate reference input source.
PGM wrt (with respect to) HD/REF1
This is the recommended method of referencing Imagestore HDTV. The
REF1 input, the upper of the 2 REF BNCs, is for a high definition tri-level
sync and is terminated to 75Ω.
PGM wrt SD/REF2
The REF2 input is for a standard definition black and burst analog sync. The
input, the lower of the 2 REF BNCs, is terminated to 75Ω. Using an SD
analog sync for HD on-air systems is NOT recommended as it may introduce
excessive jitter into the HD-SDI stream. This jitter, at the low frequency field
rate, could potentially affect the performance of downstream equipment.
PGM wrt 1/A
This option will lock the Imagestore HDTV to the incoming serial bit-stream
of input 1/A. This should only be used for single input channel units where
the 1/A input is valid at all times. In multiple input systems, if the 1/A input
is switched by a station router there may be disruption in the output signal.
Adjusting reference timing
Warning:
Reference timing should always be adjustment off-air since it can result in
loss of picture in downstream equipment. Errors may occur in the HD-SDI
stream whilst the adjustment is taking place.
VANC data such as captions and audio metadata may be missed by
downstream equipment if they are not seen to be on the same line number
that they were input on. Reference adjustment affects the line number
marking of the output stream. It needs to be adjusted to match the signal path
delays of the local facility.