Triggering and timings
139
Alvium G1 User Guide V1.1.1
Trigger signal flow
Figure 58
shows a general diagram for the trigger signal flow. The external signal can be a physical source,
such as light barrier as hardware trigger or a software trigger. This external signal starts the exposure of a
frame. The end of exposure starts the readout. High levels show the active state of a signal.
Trigger latency
In theory, a trigger creates an immediate response of the camera, depending on
the cable length. In practice, the computer may add a delay that is mostly
unpredictable, especially on Windows systems. In addition, camera electronics and
sensors have a delay.
We recommend you to trigger on the rising edge for the fastest reaction time.
Electronic rolling shutter (ERS) cameras in this document also have exposure delay,
depending on camera settings, see
Triggering with rolling shutter cameras
140. Electronic rolling shutter is commonly called rolling shutter.
Feature descriptions and firmware downloads
www.alliedvision.com/en/support/
technical-documentation/alvium-gige-documentation
www.alliedvision.com/en/support/firmware-downloads
Figure 58: Schematic trigger signal flow
Term
Description
External signal
Electrical trigger signal starting the signal flow
ExposureActive
Exposing a frame
ReadoutActive
Reading out a frame
FrameTriggerWait
Waiting for a trigger
AcquisitionActive
Enables frame acquisition: Expose, read out data, or wait for triggers.
Table 80: Trigger signal flow terms
i
External signal
džƉŽƐƵƌĞĐƟǀĞ
ZĞĂĚŽƵƚĐƟǀĞ
FrameTriggerWait
ĐƋƵŝƐŝƟŽŶĐƟǀĞ
Frame 1
1
2
Frame 2
Frame 2
Frame 1
