Pike Technical Manual
V5.2.0
179
Description of the data path
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 103: Former standard timing
on page 179 demonstrates this behav-
ior. It shows that the camera receives a shutter update command 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 con-
siderable 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 camera 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 shutter.
Therefore you can choose between the following update timing modes:
•
Standard Parameter Update Timing
(slightly modified from previous Pike
cameras)
Note
Configuration
To configure this feature in an advanced register: See
185: Advanced register: Format_7 mode mapping
Figure 103: 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
