Baumer EXG03 - 2�2 Timings; 2�2�1 Free Running Mode

8
2.2 Timings
The image acquisition consists of two seperate, successively processed components.
Exposing the pixels on the photosensitive surface of the sensor is only the rst part of the
image acquisition. After completion of the rst step, the pixels are read out.
Thereby the exposure time (t
exposure
) can be adjusted by the user, however, the time need-
ed for the readout (t
readout
) is given by the particular sensor and used image format.
Baumer cameras can be operated with two modes, the Free Running Mode and the
Trigger Mode�
The cameras can be operated non-overlapped
*)
or overlapped. Depending on the mode
used, and the combination of exposure and readout time:
Non-overlappedOperation OverlappedOperation
Here the time intervals are long enough
to process exposure and readout succes-
sively.
In this operation the exposure of a frame
(n+1) takes place during the readout of
frame (n).
Exposur
e
Readout
Exposur
e
Readout
Due to the differing CMOS sensor models installed to the Baumer EXG cameras, the
operation modes are subdevided into the respective camera models.
2.2.1 FreeRunningMode
In the "Free Running" mode the camera records images permanently and sends them to
the PC. In order to achieve an optimal (with regard to the adjusted exposure time t
exposure
and image format) the camera is operated overlapped.
In case of exposure times equal to / less than the readout time (t
exposure
≤ t
readout
), the maxi-
mum frame rate is provided for the image format used. For longer exposure times the
frame rate of the camera is reduced.
2.2.1.1 EXG03/EXG03c
Exposur
e
Readout
Flas
h
t
exposure(n)
t
flash(n)
t
flashdelay
t
flash(n+1)
t
readout(n+1)
t
readout(n)
t
exposure(n+1)
t
ash
= t
exposure
*) Non-overlapped means the same as sequential.
Imageparameters:
Offset
Gain
Mode
Partial Scan
Timings:
A - exposure time
frame (n) effective
B - image parameters
frame (n) effective
C - exposure time
frame (n+1) effective
D - image parameters
frame (n+1) effective