Guidelines When Using An Exsync Signal - Basler L800k User Manual

Operation and Features

3.4.1.3 Guidelines When Using an ExSync Signal

When using an ExSync signal to control exposure, several general guidelines must be followed:
• The ExSync signal must toggle.
• The ExSync signal period must not be lower than a defined minimum. The minimum ExSync
signal period for each camera version is shown in Table 3-1.
Video Data Output Mode
Single tap (no two-line averaging)
Dual tap (no two-line averaging)
Dual separated tap (no two-line averaging)
Single tap (with two-line averaging)
Dual tap (with two-line averaging)
Dual separated tap (with two-line averaging)
Table 3-1: Minimum ExSync Signal Period
• The ExSync signal must remain high for at least 0.1 µs.
• The minimum exposure time is 10.0 µs. This means that:
In ExSync level-controlled mode, the ExSync signal must remain low for at least 10.0 µs.
In ExSync programmable mode, the programmed exposure time must be at least 10.0 µs.
• In the ExSync programmable mode:
The maximum allowed programmed exposure time = ExSync signal period - 0.6 µs.
(If you set the exposure time to be longer than this allowed maximum, the camera will behave
as if it is in ExSync edge-controlled mode.)
• In ExSync edge-controlled and ExSync level-controlled modes, the relationship between the
fall of the line valid signal and the rise of the ExSync signal must meet the minimum require-
ments shown in Figure 2-6.
• When you are controlling exposure with an ExSync signal, using the edge-controlled mode
will give you the best performance in terms of signal-to-noise ratio.
Exposure Start Delay
When an exposure is triggered by the ExSync signal, the actual start of exposure will be delayed.
(This is commonly referred to as an exposure start delay.) The exposure start delay includes two
components: the transfer gate time and the setup time. These times vary depending on the
camera model and the expose mode you are using. Table 3-2 shows the transfer gate time and
the setup time for each camera model and exposure mode combination.
For a given combination of camera model and exposure mode:
3-6
Draft
We strongly recommend using an exposure time that is at least 10% of the
ExSync period. Exposure times shorter than 10% of the ExSync period will
increase the non-linearity of the camera's response.
L801 L802
k k
425.2 µs 212.66 µs
212.6 µs 106.33 µs
212.6 µs 106.33 µs
212.6 µs 106.33 µs
212.6 µs 106.33 µs
212.6 µs 106.33 µs
L803
k
141.86 µs
70.93 µs
70.93 µs
70.93 µs
70.93 µs
70.93 µs
BASLER L800
k