Pyramid Imaging EXO Series, Manual

Page: 64 / 135

SVS-VISTEK
Feature-Set 64
When the rising edge of trigger signal occurs after frame readout has
ended (FVAL is low) the start of exposure time is not synchronized to LVAL
and exposure time starts after a short and persistant delay.
The falling edge of the trigger signal must always occur after readout of
the previous frame has ended (FVAL is low).
Software Trigger
Trigger can also be initiated by software (serial interface).
NOTICE
Software trigger can be influenced by jitter. Avoid Software
trigger at time sensitive applications
External Trigger (Exposure Time)
External trigger with programmable exposure time. In this mode the
camera is waiting for an external trigger pulse that starts integration,
whereas exposure time is programmable via the serial interface and
calculated by the internal microcontroller of the camera.
At the rising edge of the trigger the camera will initiate the exposure.
The software provided by SVS-Vistek allows the user to set exposure time
e.g. from 60
μ
s 60 Sec (camera type dependent).
Exposure time of the next image can overlap with the frame readout of
the current image (trigger pulse occurs when FVAL is high). When this
happens, the start of exposure time is synchronized to the negative edge
of the LVAL signal (see figure)
When the rising edge of trigger signal occurs after frame readout has
ended (FVAL is low), the start of exposure time is not synchronized to LVAL
and exposure time starts after a short and persistant delay.
Exposure time can be changed during operation. No frame is distorted
during switching time. If the configuration is saved to the EEPROM, the set
exposure time will remain also when power is removed.
Detailed Info of External Trigger Mode
Dagrams below are aquivalent for CCD and CMOS technique.