User`s manual

Acquisition Control AW00118302000
118 Basler racer GigE
Line Acquisition While Obeying Timing Limits
When strictly obeying the following timing limits you can avoid overtriggering in "overlapped mode"
and "non-overlapped mode" without having to monitor the camera’s acquisition status (see also
Fig. 42 and Fig. 43 below). You must ensure that the following four conditions are fulfilled at the
same time:
 Condition one: The exposure time E is 2µs.
This is the minimum allowed exposure time also given in Section 6.1.5.2 on page 67.
 Condition two: Period F is C
1
; F follows immediately after the exposure.
The constant C
1
expresses the duration of exposure overhead. Exposure is not possible during
this period. It is generally equal to 5.4 µs as can be seen from Section on page 135, ("Factor
2"). However, when the parameter limit is removed from the Exposure Overhead parameter
(see Section 8.3 on page 110), the constant is equal to 3.4 µs. Accordingly, F must be
5.4 µs
in the general case, and
 3.4 µs when the parameter limit is removed from the Exposure
Overhead parameter (see also Table 11).
 Condition three: ExLSTrig Signal Period  Minimum allowed line period.
 Condition four: Make sure the ExposureOverlapTimeMax parameter value is set to the
appropriate value (see Table 11):
 When the parameter limit is not removed from the ExposureOverhead parameter the
ExposureOverlapTimeMax parameter value must be set to the applicable maximum value
for E. For example, for a raL2048-48gm camera the parameter value must be set to
15.1 µs.
 When the parameter limit is removed from the ExposureOverhead parameter the
ExposureOverlapTimeMax parameter value must be set tothe applicable maximum value
for E. For example, for a raL2048-48gm camera the parameter value must be set to
17.1 µs.
The parameter values become obvious from the following relation:
Appropriate ExposureOverlapTimeMax parameter value =
= Minimum allowed line period - Minimum period when exposure is not possible (i.e.
duration of exposure overhead, i.e. minimum F value).
For example, the following applies when operating e.g. an raL2048-48gm camera at full
resolution at the maximum allowed line rate (with conditions one through four fulfilled) and
without having removed the parameter limit from the ExposureOverhead parameter:
15.1 µs = 20.5 µs - 5.4 µs.
 If you increase the ExposureOverlapTimeMax parameter value above 15.1 µs while
maintaining the line period the minimum value for the duration of the exposure overhead
would be ignored and ExLSTrig signals can be considered overtriggers when in fact they
are not.
 If you decrease the ExposureOverlapTimeMax parameter value below15.1 µs you would
have to increase the duration of the exposure overhead and thereby increase the line rate.