Basler ace acA1920-155, User Manual, Page: 288 / 326

Features AW00123404000
278 Basler ace USB 3.0
3. As soon as transmission time is available, an event message for the currently earliest event in
the internal queue will be sent to the PC.
a. After the camera sends an event message, it waits for an acknowledgement. If no
acknowledgement is received within a specified timeout, the camera will resend the event
message. If an acknowledgement is still not received, the timeout and resend mechanism
will repeat until a specified maximum number of retries is reached. If the maximum number
of retries is reached and no acknowledge has been received, the message will be dropped.
While the camera is waiting for an acknowledgement, no new event messages can be
transmitted.
4. Event notification involves making some additional software-related steps and settings. For
more information, see the "Camera Events" code sample included with the pylon software
development kit.
The Event Queue
As mentioned in the example above, the camera has an event queue. The intention of the queue is
to handle short term delays in the camera’s ability to access the network and send event messages.
When event notification is working "smoothly", a single event will be placed in the queue and this
event will be sent to the PC in an event message before the next event is placed in the queue. If
there is an occasional short term delay in event message transmission, the queue can buffer
several events and can send them within a single event message as soon as transmission time is
available.
However, if you are operating the camera at high frame rates, the camera may be able to generate
and queue events faster than they can be transmitted and acknowledged. In this case:
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The queue will fill and an event overrun will occur. Events will be dropped.
Setting Your System for Event Notification
Event notification must be enabled in the camera and some additional software-related settings
must be made. This is described in the "Camera Events" code sample included with the pylon
software development kit.
Event notification must be specifically set up for each type of event using the parameter names of
event and supplementary information. The following table lists the relevant parameter names: