Description of the data path
PIKE Technical Manual
V5.0.0
166
Quick parameter change timing modes
Why new timing modes?
Former timing of the PIKE cameras showed the same behavior as MARLIN
cameras:
•
Frame rate or transfer rate is always constant (precondition:
shutter
transfer time)
•
The delay from shutter update until the change takes place: up to 3
frames.
Figure 97: Former standard timing
on page 166 demonstrates
this behavior. It shows that the camera receives a shutter update com-
mand while the sensor is currently integrating (Sync is low) with shutter
setting 400. The camera continues to integrate and this image is output
with the next FVal. The shutter change command becomes effective with
the next falling edge of sync and finally the image taken with shutter
200 is output with a considerable delay.
•
Parameters that are sent to the camera faster than the max. frame rate
per second are stored in a FIFO and are activated in consecutive images.
Principally a PIKE camera is not able to recognize how many parameter the
user will change. Due to the fact that communication between host and cam-
era is asynchronous, it may happen that one part of parameter changes is
done in image n+1 and the other part is done in image n+2.
To optimize the transfer of parameter changes there is a new timing mode
called
Quick Format Change Mode
, which effectively resets the current shut-
ter.
Therefore you can choose between the following update timing modes:
Note
Configuration
To configure this feature in an advanced register: See
175: Advanced register: Format_7 mode mapping
Figure 97: Former standard timing
Shutter Update Command
Current Charge Time
Sync
FVal
400
200
integrates image
with
with shutter eg 400
continues integrating
outputs image
with shutter 400
outputs image
with shutter 200
shutter 200
