Basler racer User Manual

AW00118508000 Acquisition Control
Basler racer Camera Link 76
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. 26 and Fig. 27 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 65.
 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 6.4.1 on page 89,
("Factor 2"). However, when the parameter limit is removed from the ExposureOverhead
parameter (see Section 8.3 on page 106), 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
ExposureOverhead parameter (see also Table 14).
 Condition three: ExLSTrig Signal Period ≥ Minimum allowed line period.
 Condition four: Make sure the ExposureOverlapTimeMaxAbs is set to the appropriate value:
 When the parameter limit is not removed from the ExposureOverhead parameter the
ExposureOverlapTimeMaxAbs parameter value must be set to 7 µs.
 When the parameter limit is removed from the ExposureOverhead parameter the
ExposureOverlapTimeMaxAbs parameter value must be set to 9 µs.
The parameter values become obvious from the following relation:
Appropriate ExposureOverlapTimeMaxAbs parameter value =
Minimum allowed line period of 12.4 µs - duration of exposure overhead (being the
minimum period after exposure when the next exposure is not yet possible, i.e. minimum F
value).
For example, the following applies when operating the camera at the maximum allowed line rate
(with conditions one through four fulfilled) and without having removed the parameter limit from
the ExposureOverhead parameter.
7µs = 12.4µs - 5.4µs.
 If you increase the ExposureOverlapTimeMaxAbs parameter value above 7 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 ExposureOverlapTimeMaxAbs parameter value below7 µs you would
have to increase the duration of the exposure overhead and thereby increase the line rate.
When you want to operate the camera at the maximum allowed line rate and
have set the ExposureOverlapTimeMaxAbs parameter value to the
appropriate value (see above) you can vary the exposure time E within the
ranges indicated in Table 14 without having to adjust the
ExposureOverlapTimeMaxAbs parameter value.

Basler racer Specifications

General

Brand	Basler
Model	racer
Category	Digital Camera
Language	English