Basler ace acA1920-155, Руководство пользователя, Страница: 240 / 326

Features AW00123404000
230 Basler ace USB 3.0
Use Case One in Overview
Use case one demonstrates synchronous triggering cycling through all the available four sequencer
sets, not disturbed by a reset. The possibility of repeatedly applying a sequencer set to a
succession of frame acquisitions is also shown.
The GPIO lines are configured for input and allow to control sequencer set advance for path 0 and
path 1 by external triggers. The frame start trigger is controlled by external signals via the opto-
isolated input line Line 1. Accordingly, sequencer operation and frame acquisition are all controlled
by external triggers. This allows tight synchronization between triggers for sequencer set advance
and frame start triggers.
The trigger assigned to path 1 goes low between most frame start triggers and, if desired, goes high
well ahead before the frame start triggers rise. This ensures that the trigger signals assigned to
path 1 have reached the desired signal levels in time before they will be evaluated by the frame start
trigger with respect to sequencer set advance.
Another aspect of sequencer set advance becomes apparent: The signal levels of the external
triggers assigned to path 1 and path 0 will matter for sequencer set advance only at the moment
when they are evaluated by the frame start trigger (not shown for path 0 in this use case). The
moment occurs when the frame start trigger signal rises assuming the frame start trigger signal is
set for rising edge triggering. The signal levels of the external triggers assigned to path 1 and path 0
that occur between frame start triggers have no effect on sequencer set advance.
Use Case One in Detail
Assuming that the sequencer sets are configured according to Table 41 on page 229 and the
camera is not acquiring images, the sequencer feature operates as follows:

When the Sequencer Mode parameter value is set to On the sequencer feature becomes
enabled for the application of sequencer sets during image acquisitions. The transitional
"dummy" sequencer set with index number -1 is loaded into the active set, overwriting the
previous sequencer parameter values (Section 8.6.2 on
page 215 ).

A trigger signal assigned to path 1 is received, setting the signal level to high.

When the frame start trigger signal was received the trigger signal assigned to path 1 is found
to be high. As a result, the frame start trigger triggers the loading of the next sequencer set,
that is sequencer set 0, into the active set. Sequencer set 0 overwrites the parameter values of
sequencer set -1 in the active set.
A frame acquisition is carried out using the parameter values of sequencer set 0. The image
data are processed and transmitted out of the camera.
The trigger signal assigned to path 1 goes low.

The trigger signal assigned to path 1 goes high.

When the next frame start trigger signal was received the trigger signal assigned to path 1 is
found to be high. As a result, the frame start trigger triggers the loading of the next sequencer
set, that is sequencer set 1, into the active set. The parameter values for sequencer set 1
overwrite the parameter values for sequencer set 0 in the active set.
A frame acquisition is carried out using the parameter values of sequencer set 1. The image
data are processed and transmitted out of the camera.