Synchronization Selection (LL/INT)
This switch is used to select the synchronisation mode of the camera. When
the camera is connected to an AC supply (either Mains or 24V Low Voltage),
the Line-lock (LL) mode can be used to lock the camera's frame rate to the
mains frequency so that each camera in the system is triggered at the same
point on the supply's AC-cycle. See also
Potentiometer. The default setting is LL.
WARNING!
The LL/INT switch must be set to INT when
operating from 12 VDC.
Line Lock Phase Adjustment Potentiometer
When the camera is in Line-lock mode it is possible to adjust the point on the
AC cycle at which the camera triggers. This facility is provided so that
cameras that are connected to different mains phases may still be
synchronized.
The V-Phase adjustment potentiometer allows the line lock phase trigger
point to be adjusted by: 1:120°. Rotating the potentiometer clockwise
advances the trigger point and turning it counterclockwise retards the trigger
point. The factory default setting is the zero crossing point. If all cameras in a
system are on the same mains phase then no line lock phase adjustment
should be made. See also
DD Lens Level Adjustment Potentiometer
The Direct Drive lens level is controlled by this potentiometer. The video
output signal is converted into DC voltage by circuitry within the camera. The
potentiometer sets a reference voltage against which this derived DC voltage
is compared. If the DC voltage is less than the reference level, the lens iris
opening is increased. If the DC voltage is greater than the reference level, the
lens iris opening is decreased. This control loop attempts to continually
match the DC voltage derived from the video signal to the reference voltage
set by the potentiometer. This feature allows the installer to set the required
video output amplitude (for example, 1 Vp-p) that the lens should strive to
maintain.
Rev 1.01
Line Lock Phase Adjustment
Synchronization Selection
4
(LL/INT).
Document 900.0350
05/05