Pike Technical Manual
V5.2.0
216
Controlling image capture
The following screenshot shows an example of broadcast commands sent with
the Firedemo example of FirePackage:
•
Line 1 shows the broadcast command, which stops all cameras connected
to the same IEEE 1394 bus. It is generated by holding the <shift> key down
while clicking on <Write>.
•
Line 2 generates a
broadcast one_shot
in the same way, which forces all
connected cameras to simultaneously grab one image.
Jitter at start of exposure
The following chapter discusses the latency time which exists for all Pike CCD
models when either a hardware or software trigger is generated, until the actual
image exposure starts.
Owing to the well-known fact that an
Interline Transfer CCD
sensor has both a
light sensitive area and a separate storage area, it is common to interleave
image exposure of a new frame and output that of the previous one. It makes
continuous image flow possible, even with an external trigger.
The uncertain time delay before the start of exposure depends on the state of the
sensor. A distinction is made as follows:
FVal is active
the sensor is reading out, the camera is busy
In this case the camera must not change horizontal timing so that the trigger
event is synchronized with the current horizontal clock. This introduces a max.
uncertainty which is equivalent to the line time. The line time depends on the
sensor used and therefore can vary from model to model.
FVal is inactive
the sensor is ready, the camera is idle
Figure 114: Broadcast one-shot
