1.19 Appendix A. Specific Camera / Sensor Data 175
1.19.1.1.3 CCD Timing
Name Description Pixel clock
12 MHz 24 MHz
t
trig
Time from trigger
(internal or external) to exposure start
10us
t
trans
Image transfer time
(move image to readout cells in CCD)
64us 32us
t
readline
time needed to readout a line 64us 32us
t
vshift
time needed to shift unused lines away 3.15us 1.6us
t
wait
minimal time to next trigger 64us 32us
t
exposure
Exposure time 2uss - 128s
t
readout
Image readout time
(move image from readout cells to memory
t
readout
= (ActiveLines ∗ t
readline
) + (510 - ActiveLines) ∗ t
vshift
1.19.1.1.3.1 Timings
Note
In partial scan mode (readout window ysize < 480 lines).
To calculate the maximum frames per second (FPS
max
) you will need following formula (ExposeMode: Standard):
FPS_max = 1
-----------------------------------------------
t_trig + t_readout + t_exposure + t_trans + t_wait
(ExposeMode: Overlapped):
t_trig + t_readout + t_trans + t_wait < t_exposure: FPS_max = 1
---------------
t_integ
t_trig + t_readout + t_trans + t_wait > t_exposure: FPS_max = 1
-------------------------------------
t_trig + t_readout + t_trans + t_wait
Example: Frame rate as function of lines & exposure time
Now, when we insert the values using exposure time of, for example, 65 us, 100 lines and 12MHz pixel clock
(ExposeMode: Standard):
MATRIX VISION GmbH
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