360 Systems Image Server 2000 - Manual (Page 65)

Image Server 2000 Owner’s Manual Page 65
Advanced Topics
System Timing
The Image Server is capable of using an external genlock signal as a timing reference. This allows
the outputs to be timed the same as other video signals in a facility. There are three adjustments to
fine tune this synchronization to compensate for differences in equipment and wiring. Genlock
LINES and SUBPELS set the sync relationship of all of the outputs to the incoming reference. Color
timing is adjustable for each channel independently with the SC/H PHASE setting.
These settings should be made in the following order:
1. Genlock Lines: This is a global setting for all of the outputs. It rarely ever needs to be
adjusted. It allows the output timing to be varied by a line of video. This would be
adjusted so that the output of the first line of video happens concurrently with other
contributing inputs. The visible effect is that the picture will rise or fall by one line when
viewed at the output of a video switcher or on a genlocked monitor. Note that this setting
can cause vbi lines such as Closed Captioning and VITC to appear on different (and
possibly inappropriate) lines.
2. Genlock Subpels: This is a global setting for all outputs. It allows the output timing to be
adjusted by half a pixel. The visible effect is that the picture will move horizontally when
viewed at the output of a video switcher or genlocked monitor. The adjustment is made
by using a waveform monitor and comparing the falling edge of horizontal sync between
the output and another contributing signal (not the genlock signal.) Some video switchers
indicate when a signal is timed within spec; this can be used to determine when the
setting is correct. If correct system timing is indicated over a range of subpel settings,
determine the extreme of the range and set the value in the middle.
3. SC/H Phase: This is a setting per channel, found in the Transport>Options>Configure
menu (it does not appear in the Playlist’s Options menu.) The adjustment is made by
using a vector scope display referenced to the color reference, usually the genlock signal.
Play back the zCBARS clip. Adjust the SC/H PHASE to align the color with the vector
scope points. Note that it is normal to see some slight periodic variation in the vector
display.