Filter
Top Products
Chapter 5 Timing Modes 51
Free Run
In the Free Run Kinetics mode, the controller takes a series of images, each with the
Exposure time set through the software (in WinView32, the exposure time is set on the
Experiment Setup|Main tab page). The time between image frames, which may be as
short as a few microseconds, is limited by the time required to shift an image under the mask:
this interimage time equals the Vertical Shift rate (specified in
µ
sec/row) multiplied by the
Window Size (the number of rows allocated for an image frame). The exact number of
frames depends on the selected Window Size and is equal to the number of pixels
perpendicular to the shift register divided by the Window Size.
Example: Referring to the readout shown in Figure 19, there are 6 pixels perpendicular to
the shift register and the Window Size is 2 pixels high. The number of frames is 3. If the
Vertical Shift Rate for the CCD is 1.6
µ
sec/row, the Shift time will be 3.2
µ
sec per frame.
Integrate signals (SHUTTER) or Readout signals (NOTSCAN) are provided at the
BNC for timing measurements.
NOTSCAN Signal
Shutter
opening
time
Shutter
closing
time
Readout
START ACQUIRE command from the software issent automatically
when ACQUIRE or FOCUS is clicked on in the software.
Exposure
Shift
SHUTTER Signal
START ACQUIRE
Figure 22. Free Run Timing Diagram
Single Trigger
Single Trigger Kinetics mode takes an entire series of images with each External Trigger
Pulse (applied at the Ext. Sync BNC on the control board of ST-133). After the series is
complete the shutter closes and the CCD is read out at normal speeds. Once the readout is
complete the camera is ready for the next series of exposures. This timing is shown in
Figure 23, where a single External trigger pulse is used to collect a burst of 6 frames.
NOTSCAN Signal
Shutter
opening
time
Shutter
closing
time
Readout
START ACQUIRE command from the software issent automatically
when ACQUIRE or FOCUS is clicked on in the software.
External Trigger
Exposure
Shift
SHUTTER Signal
START ACQUIRE
Figure 23. Single Trigger Timing Diagram