Hardware triggers, timestamps and PTP answer different questions: when acquisition is requested, what a recorded time represents, and whether device clocks can be compared. Opening multiple images at once does not answer these questions. First identify whether the task compares exposure start, exposure midpoint or another event, then choose acquisition and measurement methods.
Hardware triggers control a selected event
An external electrical signal can serve as a supported camera trigger source. Check signal levels, polarity, input delay, trigger selection and camera readiness. Basler triggered-acquisition documentation distinguishes trigger types such as frame start and exposure start, and explains that a camera may not accept a trigger when it is not ready. A shared trigger source does not remove internal device delays; measure the actual exposure relationship.
Check the event and clock behind each timestamp
| Time record | Questions to check | Conclusion not established by the record alone |
|---|---|---|
| Camera timestamp | Corresponding event, clock and units | Similar numbers across devices establish simultaneous exposure |
| Host arrival time | Recording point in the interface, thread or buffer | Arrival order equals exposure order |
| Display time | Decoding, queuing and refresh behavior | Images on one screen were acquired at the same instant |
Do not directly subtract device timestamps and host arrival times without an established clock relationship. Check counter rollover, changed origins after restart and missing time records. Use the device and SDK documentation for the meaning of each field.
PTP synchronizes clocks, not exposure schedules by itself
Basler PTP documentation describes clock synchronization on supported devices and the influence of network conditions. After enabling PTP, check synchronization status and configure a trigger or scheduled-acquisition mechanism supported by the target device. Synchronized clocks are not a measurement of synchronized exposures, and do not guarantee simultaneous network delivery or display refresh.
Cover the actual imaging mode in the measurement method
Keep original records of the events being compared, identifying measurement instruments, time sources, workload and sample scope. For rolling-shutter images, check exposure timing across image rows against the sensor mode. Comparing frame-start times does not establish simultaneous exposure across all rows. This article explains mechanisms and checks, not verified timing precision or compatibility for a particular device.
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