# Trigger Settings

The Trigger tab of the Acquisition panel allows you to configure the following trigger settings:

Parameter | Description
--- | ---
Trigger Type | Defines the type of trigger signal that begins an image acquisition. Single: an external trigger event triggers the start of an acquisition and an inspection. Self: acquisitions and inspections occur continuously.
Trigger Source | Specifies the trigger source for the acquisition: Software: select this option if you want to trigger acquisition manually, for example by clicking a button in the WebHMI interface of the configured job. Input Line: select this option to trigger acquisition using an external hardware signal line generated by a triggering device.
Scan Length Mode | Specifies whether scan length is fixed or variable: Fixed: The vision system scans according to the number of profiles. Variable: The vision system scans as long as the trigger signal is active. Connect a photo eye to the trigger input to acquire larger or smaller point clouds according to the inspected part. You must configure a maximum scan length with the Requested Scan Length (mm) option in Point Cloud Settings. The vision system stops acquisition if it reaches the value of Requested Scan Length (mm), even though the laser remains on until the trigger signal becomes inactive. Note: This setting is enabled only if Trigger Source is set to Trigger Input Line.
Extend Trigger Length | Increases the length of the trigger beyond the signal on the trigger input line. This parameter must be smaller than Requested Scan Length (mm), which determines the maximum scan length. Note: This setting is enabled only if Scan Length Mode is set to Variable. Tip: If the photo eye cannot detect the first portion of the inspected part: Provide extra margin at the beginning of the acquisition by configuring Trigger Delay to be smaller than the physical distance between the photo-eye and the laser plane. Compensate for the trigger delay by stretching the scan length with Extend Trigger Length to acquire the whole part.
Motion Input | Defines the acquisition driving logic for every profile: Encoder: profile acquisition is triggered by a physical encoder generating signals (or ticks) for acquisition. Time: profile acquisition is triggered at a fixed time interval by an internal clock generating fixed-frequency pulses. Note: This setting affects field correction. Therefore, make sure to configure it before performing field correction on the device in the Correction Settings.
Encoder Type | Specifies whether the encoder signal used for acquisition is single or dual-channel: Single Channel: select this option for single-channel encoders. Such encoders can only detect the presence of the motion, but not its direction. Note: If this encoder type is selected, you do not have to set the Encoder Direction, as any motion (incremental or decremental) will trigger an acquisition. Dual Channel: select this option for dual-channel encoders. Such encoders can detect both the presence and the direction of the motion. Note: If this encoder type is selected, you must also specify the Encoder Direction. The vision system then performs an acquisition only if the detected motion has the same direction as specified with the Acquisition Direction setting. Note: This setting affects field correction. Therefore, make sure to configure it before performing field correction on the device in the Correction Settings.
Encoder Counter | Indicates the current encoder position so that you can check if the encoder is wired correctly and working properly. The Encoder Counter always has a positive value that you can reset with the Reset button. Note: The Encoder Counter works only if Motion Input is set to Encoder.
Time Trigger Delay (ms) | Specifies a time delay (in milliseconds) between the trigger signal and the start of the acquisition. The value range is 0 – 10,000, and the default value is 0, which means no time delay between the trigger signal and the acquisition. Note: This setting is enabled only if Motion Input is set to Time.
Distance Trigger Delay (mm) | Specifies the amount of distance (in mm) between the trigger signal and the start of the point cloud acquisition. The value range is 0 – 10,000, and the default value is 0, which means no distance-based delay between the trigger signal and the acquisition. Note: This setting is enabled only if Motion Input is set to Encoder. The system uses a multiple of the Encoder Resolution closest to the specified value.
Acquisition Direction | Specifies in which motion direction you want to acquire. This setting is independent of the Positive Encoder (+) setting. Laser to Lens: the vision system acquires image data if the motion direction is from the cast laser to the lens of the vision system. Use this setting when the object is approaching the vision system from the side where laser is located. Lens to Laser: the vision system acquires image data if the motion direction is from the lens of the vision system to the cast laser. Use this setting when the object is approaching the vision system from the opposite side where laser is located. Tip: By default, you can trigger acquisitions only in one direction. If you want to trigger acquisitions in both directions (that is, both toward and away from the vision system), change the Acquisition Direction setting after performing the first acquisition.
Acquisition Timeout | Specifies the amount of time (in milliseconds) before an acquisition times out after a trigger. If Motion Input is set to Encoder, the acquisition times out if the movement distance registered by the encoder does not surpass the Requested Scan Length specified in the Point Cloud Settings, or if the acquisition does not complete within the specified Acquisition Timeout period. If Motion Input is set to Time, the acquisition times out if the acquisition does not complete within the specified Acquisition Timeout period.

### Advanced Settings

Parameter | Description
--- | ---
Trigger Debounce (μs) | The minimum trigger pulse duration (in μs) to be considered valid. Any pulse shorter than the specified duration is considered noise and will be ignored. This setting is only available if you have set Trigger Source for Input line.
Encoder Debounce (μs) | The minimum encoder pulse duration (in μs) to be considered valid. Any pulse shorter than the specified duration is considered noise and will be ignored. This setting is only available if you have set Motion Input for Encoder. If your run time is generally consistent, but there is a large difference between the average and the maximum frame rates, it is possible that there is noise in the encoder signal. In such cases, try increasing Encoder Debounce to stabilize performance.