Trigger arrived, but no image? Check the Cognex acquisition buffer
Conceptual illustration, not an actual product screen or field result.
Do not diagnose a broken camera from one symptom
An absent inspection image does not, by itself, establish a hardware or communication fault. This guide covers one documented condition in the Cognex In-Sight Spreadsheet 26.2.1 Acquisition Panel, not every possible cause of missed acquisition.
An image buffer is temporary space for an image
The manual explains that acquisition uses an available buffer, which remains locked during job execution. Display queues and some image-writing functions can also occupy buffers. A function such as WriteImage may keep a buffer locked even after the job has executed.
The documented Image Buffers setting spans 6–25. That range does not reveal the current device configuration, available capacity at a given moment or whether the maximum would prevent misses. Verify the actual model, version and operating conditions first.
Separate the trigger, acquisition and result transfer
| Check | Documented distinction |
|---|---|
| Trigger receipt | A request to start acquisition; it does not by itself prove that an image was produced. |
| Available acquisition buffer | In Single Trigger mode, no available image buffer means acquisition does not occur. |
| Missed-acquisition signal | The discrete output must be configured for ERR: Missed Acquisition. Do not assume it is always enabled by default. |
| Inspection result buffer | An image-acquisition buffer is not the same as a buffer used to transfer inspection results. This guide concerns the former. |
Hypothetical example: a trigger with nowhere to put the image
The illustration simplifies possible image occupancy by inspection, display and writing work. If no image buffer is available when a new Single Trigger arrives, the documented acquisition does not occur. The diagram is not an actual camera interface, measured memory occupancy or a count of missed production images.
Read-only checks before a setting change
- Confirm product, firmware, software version and the actual Trigger Type.
- Inspect the image-buffer setting and the inspection, display and image-writing paths. Configured capacity is not the same as current availability.
- Confirm whether and where ERR: Missed Acquisition is assigned to a discrete output. No signal does not establish successful acquisition.
- Compare actual images and inspection records with triggers for the same interval. Do not change production settings solely from this guide.
Evidence limits
This is manufacturer-document interpretation using AI-generated Korean narration and original conceptual diagrams. No customer camera, PLC, production outage or recovery was tested. No detection rate, acquisition-loss rate or improvement was measured. Operational changes or reproduction tests require authorization and an isolated environment.