8.Features
© 2023 China Daheng Group, Inc. Beijing Image Vision Technology Branch 168
An image block is discarded (BlockDiscard)
The trigger signal overflow (FrameStartOvertrigger)
The image frame block is not empty (BlockNotEmpty)
The event queue is overflow (EventOverrun)
Every event has a corresponding enable status, and in default all the events’ enable status are disable.
When using the event function, you need to enable the corresponding event firstly and set the port of the
event channel, the timeout of the event retransmission, and the number of times the event resends to the
camera. When the retransmission timeout of the event is set to 0, the event sent by the camera will not
require the host to return the reply packet. When the port value of the event channel is set to 0, the camera
will not send the event to the host. In other cases, the camera needs to receive a host reply package
before sending the next event. When the event that the camera sends does not receive the reply packet,
the camera will retransmit the event according to the retransmission timeout and retransmission times set.
The effective information contained in each event is shown in Table 8-5:
No.
Event Type
Information
1
ExposureEnd Event
Event ID
Frame ID
Timestamp
2
BlockDiscard Event
Event ID
Timestamp
3
EventOverrun Event
Event ID
Timestamp
4
FrameStartOvertrigger Event
Event ID
Frame ID
Timestamp
5
BlockNotEmpty Event
Event ID
Timestamp
Table 8-5 The effective information of each event
Among them: the timestamp is the time when the event occurs, and the timer starts when the camera is
powered on or reset. The bit width of the timestamp is 64 bits, and the unit is 20ns.
8.6.1.
ExposureEnd Event
If the ExposureEnd Event is enabled, when the camera’s sensor has been exposed, the camera sends
out an ExposureEnd Event to the host, indicating that the exposure has been completed.