Trigger

Supported by...

PL-B700 & 900 series cameras and board-level imaging modules

• The 740 supports Trigger Modes 0, 1, 2, 3 and 14.

• The 760 supports Trigger Modes 0, 1, 2, 3 and 14.

• The 770 supports Trigger Modes 0 and 14.

• The 780 supports only Trigger Mode 0.

• The 950 supports Trigger Modes 0, 1, 2, 3 and 14.

PL-D enclosed trigger and board-level cameras

• Most PL-D cameras support modes 0, 1, and 14.

• PL-D726 and PL-D7620 support only mode 0.

• PL-D7715 supports only modes 0 and 14.

Note:   PL-D729 does not support hardware trigger.

Description

Trigger controls the response of the camera to an external trigger input. Trigger functionality is required for industrial and machine vision applications where the timing of the image capture is determined by external events. The trigger can operate in a number of modes which provide flexibility when interfacing the camera with external equipment. The modes are defined below and are consistent with the IIDC specification.

The trigger can be considered an event rather than just an external signal. The type of the event can also be defined as hardware (an external electrical signal), free-running (an internal generated signal), or software generated.

Trigger Polarity

The polarity of the trigger determines whether the trigger event is declared on the falling or rising edge of the trigger signal and it depends on a camera internal hardware trigger implementation.

All PL-B cameras, and PL-D enclosed cameras

The PL-B enclosed, the PL-B board-level, and the PL-D enclosed cameras have optically isolated inputs and outputs, which drive or are driven by TTL logic levels. For triggering these camera models on the Rising edge, the polarity of the trigger should be set to Positive (Active High). Please refer to the Hardware articles below for the mechanical & electrical interface to the trigger signals, to get a proper understanding of polarity

- Trigger and GPOs - PL-B700/900 Series

- Trigger and GPIO - PL-D700 Series Enclosed Cameras

PL-D board-level cameras

The PL-D board-level cameras are driven by the same TTL logic as the PL-D enclosed cameras. However, for triggering these cameras on the Rising edge, the polarity of the trigger should be set to Negative (Active Low) since the optic isolation circuits are not present. Please refer to the PL-D Board level interface article, for the mechanical & electrical interface to the trigger signals of the PL-D board-level camera, to get a proper understanding of polarity

Trigger Delay

The delay referred to in the feature controls below is a programmable delay. To determine the full electrical propagation delay, consult the trigger timing diagram.

- PL-B Timing Diagrams

- PL-D Timing Diagrams

Trigger with Controlled Lighting

For cameras with the rolling shutter such as: PL-B770 models, PL-B780 models, PL-D726, and PL-D775, refer to Trigger with Controlled Lighting article.

Additional Information

For additional information, please refer to the Trigger and GPOs - PL-B700/900 Series and the Trigger and GPOs - PL-D700 Series sections.

API Control

PxLGetFeature, PxLSetFeature

Note: The stream state must be off (STREAM_OFF) to modify this feature. See PxLSetStreamState.

Feature Flags

Trigger Modes

Trigger Mode Definitions:

In the following explanation, trigger input is in case of 'Low Active'. (Trigger_Polarity = 0)

Trigger Mode 0:

The camera starts integration of the incoming light from the external trigger input falling edge. Integration time is defined by the Shutter feature. No parameter is needed.

Trigger Mode 1:

The camera starts integration of the incoming light from the external trigger input falling edge. Integration time is equal to the low state time of the external trigger input.The value of the Shutter feature is ignored. No parameter is needed.

Trigger Mode 2:

The camera starts integration of incoming light from the first external trigger input falling edge. At the N-th (parameter) external trigger input falling edge, integration will be stopped. Parameter is required and shall be two or more. (N>=2)

Trigger mode 3:

This is an internal trigger mode. The camera will issue the trigger internally, the cycle time equal to N (Parameter) times the cycle time of the fastest frame rate. The integration time of the incoming light is defined by the Shutter feature. Parameter is required and shall be one or more (N>=1). This effectively reduces the frame rate of the camera by 1/N without reducing the speed of communication on the bus.

Exposure duration is defined by the Shutter feature

Trigger Mode 14:

The camera will capture N (parameter) frames after a trigger at the integration time and frame rate specified by the Shutter and Frame Rate Features.

Trigger Types

Defined in PixeLINKTypes.h

Parameters