Allied Vision Alvium 1800 Series, User Manual

Page: 208 / 235

208 Alvium USB Cameras User Guide V3.6.4
Triggering
Trigger features and UserSetDefault
See Trigger features and UserSetDefault on page 167.
Trigger delay with 1800 U-120 cameras
If sensor related parameters are changed
directly before
sending an external
trigger, the trigger delay can be increased. This relates to Frame rate jitter on page
215.
Triggering with rolling shutter cameras
This section describes triggering behavior for
1800 U-500m/c, U-501m NIR,
U-1240m/c, and U-2050m/c
. Figure 86 shows how an external signal triggers
exposure and readout for cameras with rolling shutter (RS) sensors. Like for global
shutter (GS) sensors, readout has a constant duration, acquisition must be active
to enable exposure, the end of exposure starts readout.
Rolling shutter (RS) sensors run in cycles where
readout area equals exposure area .
Overlapping triggering is not supported. If exposure time is shorter than readout
time, exposure starts with a delay:
Exposure start delay = exposure area – exposure time.
Figure 86: Triggering rolling shutter (RS) cameras
External signal
Sensor cycle state
1 2 3
džƉŽƐƵƌĞĐƟǀĞР
ZĞĂĚŽƵƚĐƟǀĞС
4 5 6
1
1
2
2
3
3
Readout area Exposure area
Delay П Delay П
Idle Readout area Exposure area Readout area Exposure area
П Exposure start delay
РĐƟǀĞǁŚĞŶĂůůůŝŶĞƐĂƌĞĞdžƉŽƐŝŶŐƐŝŵƵůƚĂŶĞŽƵƐůLJ͘dŚĞƌĞĨŽƌĞ͕džƉŽƐƵƌĞĐƟǀĞŝƐƐŚŽƌƚĞƌƚŚĂŶdžƉŽƐƵƌĞdŝŵĞ͘
С>ŽŐŝĐĂůƐƚĂƚĞ͕ŶŽƚĂƵƐĞƌĨĞĂƚƵƌĞ