GX1910 Technical Manual
Page 33
Notes on Triggering
Definitions
o
User Trigger is the trigger signal applied by the user.
o
Logic Trigger is the trigger signal seen by the camera internal logic.
o
Tpd is the propagation delay between the User Trigger and the Logic Trigger.
o
Exposure is high when the camera image sensor is integrating light.
o
Readout is high when the camera image sensor is reading out data.
o
Trigger Latency is the time delay between the User Trigger and the start of
Exposure.
o
Trigger Jitter is the error in the Trigger Latency time.
o
Trigger Ready indicates to the user that the camera will accept the next trigger.
o
Registered Exposure Time is the Exposure Time value currently stored in the
camera memory.
o
Expose Start Delay is the delay time from the start of Exposure to valid Trigger
Ready. It is the Registered Exposure Time subtracted from the Readout time and
indicates when the next Exposure cycle can begin such that the Exposure will end
after the current Readout.
o
Interline Time is the time between sensor row readout cycles.
o
Imaging is high when the camera image sensor is either exposing and/or reading out
data.
o
Idle is high if the camera image sensor is not exposing and/or reading out data.
Rules
o
The User Trigger pulse width should be at least three times the width of the Trigger
Latency as indicated in the Specifications section of this document.
o
The end of Exposure will always trigger the next Readout.
o
The end of Exposure must always end after the current Readout.
o
The start of Exposure must always correspond with the Interline Time if Readout is
true.
o
Expose Start Delay equals the Readout time minus the Registered Exposure Time.
Triggering during the Idle State
o
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.
o
In this case, Trigger Latency and Trigger Jitter are as indicated in the Specifications
section.