ALLIED Vision Technologies Prosilica GS2450 - Manual (Page 37)

Prosilica GS Technical Manual V2.0.5
37
Camera interfaces
Trigger rules
• The end of exposure will always trigger the next readout.
• The end of exposure must always end after the current readout.
• The start of exposure must always correspond with the interline time if
readout is true.
• Exposure start delay equals the readout time minus the registered expo-
sure time.
Triggering during the idle state
For applications requiring the shortest possible Trigger Latency and the smallest
possible Trigger Jitter the User Trigger signal should be applied when Imaging is
false and Idle is true. In this case, Trigger Latency and Trigger Jitter are as indi-
cated in the
camera specifications .
Triggering during the readout state
For applications requiring the fastest triggering cycle time whereby the camera
image sensor is exposing and reading out simultaneously, apply the User Trigger
signal as soon as a valid Trigger Ready is detected. In this case, Trigger Latency
and Trigger Jitter can be up to 1 row time since Exposure must always begin on
an Interline boundary.
Trigger ready Indicates to the user that the camera will accept
the next trigger
Registered exposure time Exposure time value currently stored in the camera
memory
Exposure start delay Registered exposure time subtracted from the
readout time and indicates when the next expo-
sure cycle can begin such that the exposure will
end after the current readout
Interline time Time between sensor row readout cycles
Imaging High when the camera image sensor is either
exposing and/or reading out data
Idle High if the camera image sensor is not exposing
and/or reading out data
Note

The user trigger pulse width should be at least three times the
width of the trigger latency as indicated in Chapter
Specifications on page 12.
Term Definition
Table 11: Explanation of signals in timing diagram