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Alvium USB Cameras User Guide V3.3.0
Triggering
Trigger signal flow
Figure 77
shows an ideal 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.
Features availability
States shown in the following graphic apply to Alvium USB cameras. Not all of the
corresponding features may be supported. See the Alvium Cameras Features
Reference at
www.alliedvision.com/en/support/technical-documentation/
for details.
Figure 77: Schematic trigger signal flow
Term
Description
External signal
Electrical trigger signal starting the signal flow
ExposureActive
Exposing a frame
Readout Active
Reading out a frame (logical state, not a user feature)
FrameTriggerWait
Waiting for a trigger
AcquisitionActive
Enables frame acquisition: Expose, read out data, or wait for triggers.
Table 90: Trigger signal flow terms
External signal
džƉŽƐƵƌĞĐƟǀĞ
ZĞĂĚŽƵƚĐƟǀĞ
FrameTriggerWait
ĐƋƵŝƐŝƟŽŶĐƟǀĞ
Frame 1
1
2
Frame 2
Frame 2
Frame 1