# Acquisition Signals

The behavior of the Acquisition Signals may differ depending on which trigger mode the vision system uses. The vision system triggering modes can be classified as Single or Self-triggering. Single trigger mode supports selecting and filtering on different trigger sources such as Trigger Input Line, vision system Trigger Button, Native Mode, UDP, Trigger bit set by the PLC and WebHMI.

Note: Unless specified otherwise, the behavior of the signals described below applies to all triggering modes.

The Acquisition Signals are the following:

- [out] Trigger Enable:

  Trigger Enable only affects triggering in Single mode if FFP trigger source is selected. Setting this signal allows the vision system to accept triggers from the PLC by setting the Trigger Ready status bit when the vision system is in the online state. Typically this bit is set once and left on, and the Trigger bit is set or cleared to actually trigger. This bit needs to be set at least 1 IO cycle before the Trigger bit is set so the vision system is ready to receive triggers. The vision system sets the Trigger Ready bit to signify that it is ready to accept triggers.

- [out] Trigger:

  A rising edge on the Trigger bit indicates a request for the vision system to begin an acquisition. Setting the Trigger bit does not guarantee that an acquisition starts or that an acquisition completes successfully.

  When the Trigger Enable signal is cleared, the Trigger signal only effects the Trigger Acknowledge, Error and ErrorID signals. When the Trigger Enable is cleared, a falling edge on the Trigger signal clears the Trigger Acknowledge signal.

- [in] Trigger Ack:

  Trigger Ack is set to acknowledge a trigger request. The Trigger Ack bit does not indicate that an acquisition has been started just that the trigger request has been received by the vision system.

  The following events clear the Trigger Ack bit:

  - Trigger is cleared.

  - Trigger Enable is cleared.

  The Trigger Ack bit is inactive and remains low when the vision system is configured for Self triggering.

- [in] Trigger Ready:

  Trigger Ready is set when the Trigger Enable signal and Online bits are set and the vision system is able to accept trigger requests. The Trigger Ready bit is low in the following cases:

  - The vision system is offline.

  - Trigger Enable is low.

  - An acquisition is in progress.

  - The configurable number of image acquisition buffers has been used and none are available for another acquisition currently.

  The Trigger Ready bit is inactive and is always low when the vision system is configured for Self trigger mode.

- [in] Acquisition Error:

  The Acquisition Error bit is set when a trigger is requested but a corresponding acquisition is not started. The Acquisition Error bit only indicates that a trigger request did not start an acquisition. The failure of an acquisition does not set the Acquisition Error bit.

  This bit changes when the following conditions occur:

  - Acquisition Error bit set by a trigger sent while an acquisition is in progress.

  - Acquisition Error bit is cleared when the next acquisition is successfully triggered.

  When the Trigger Enable bit is cleared in Single trigger mode, the Error and ErrorID bits are set, while the Acquisition Error bit does not get set. Otherwise, in Single trigger mode, the following events set the Acquisition Error bit:

  - A trigger is requested while an acquisition is in progress.

  - A trigger is requested while the vision system is offline.

  - A trigger is requested but there are no image buffers available to hold the image.

  When the vision system is configured for Self Triggering, the following events set the Acquisition Error bit:

  - No image buffers available.

  In all triggering modes, the following events clear the Acquisition Error bit:

  - A successful trigger request.

  - The falling edge of Trigger Enable.

- [in] Acquisition ID:

  The Acquisition ID value is set on the start of an acquisition. A new Acquisition ID does not guarantee that the acquisition is successful. Acquisition ID values range from 0 to 65565. The updated Acquisition ID is returned when Trigger Ack is cleared, actually is set between Trigger Ack clearing and Exposure Complete being set.

- [in] Exposure Complete:

  The Exposure Complete bit is set when the exposure of an image completes. The Exposure Complete bit is cleared by setting the Clear Exposure Complete bit.

  If an Exposure Complete event occurs while the Clear Exposure Complete signal is high, the Exposure Complete event remains in the cleared state even if it could be set. When the Clear Exposure Complete signal is cleared, the Exposure Complete signal is set. This signal setting behavior is effected by the exposure settings in acquisition.

- [out] Clear Exposure Complete:

  Setting the Clear Exposure Complete bit clears the Exposure Complete bit. See Exposure Complete signal above for more details.