Trigger Mode - IDS uEye series User Manual

6.1.2

Trigger Mode

In trigger mode, the sensor is on standby and starts exposing on receipt of a trigger signal. A trigger
event can be initiated by a software command (software trigger) or by an electrical signal via the
camera's digital input (hardware trigger). For the specifications of the electrical trigger signals, see
the Electrical Specifications chapter.
In the camera properties, choose which trigger mode you want to use:
· Software trigger mode
When this mode is enabled, calling the Snap function triggers the capture of an image, which is
then transferred to the PC. If you call the Live function in this mode, the image capture is triggered
continuously and images are transferred continuously.
· Hardware trigger mode
When this mode is enabled, calling the Snap function makes the camera ready for triggering just
once. When the camera receives an electrical trigger signal, one image is captured and
transferred.
If you call the Live function, the camera is made ready for triggering continuously. An image is
captured and transferred each time an electrical trigger signal is received; the camera is then
ready for triggering again (recommended procedure).
· Freerun synchronization
In this mode, cameras running in freerun mode (live mode, see above) can be synchronized with
an external trigger signal. The cameras still remain in freerun mode. The trigger signal stops and
restarts the current image capture process. You can use this mode to synchronize multiple
cameras that you are operating in the fast live mode. Not all camera models support this mode.
© 2009 IDS Imaging Development Systems GmbH
In trigger mode, the maximum frame rate is lower than in freerun mode because the
sensors expose and transfer sequentially. The possible frame rate in trigger mode
depends on the exposure time.
Example: At the maximum exposure time, the frame rate is about half as high as in freerun
mode; at the minimum exposure time, the frame rate is about the same.
Figure 23: Hardware trigger mode with continuous image capture
6 Camera Basics
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