HSDIO Advance trigger

[Valentin87]

In the example to HSDIO Dynamic Acquisition of Multiple Records.vi used Advance trigger. I have some questions on its application:
1). If we have a trigger, for example, which appears with a frequency of 1 MHz, data each time (when front appears) are received, i.e. there are no gaps in the data acquiring? Can it happen that we will acquire data on the 1st trigger, 5th, 9th, and so on?
2).  What is absolute timestamp in waveform information? This is the start time of each record HSDIO?

[Case_in_Point]

Hi Valentin,

I'm not completely positive on what you're asking for your first question, but it sounds like it depends on how you configure the task. For multi-record acquisitions, the triggering condition defines when each record is taken. Essentially, the card watches the Source line, and when it detects a digital edge, it starts acquiring a record. How long that lasts depends on how many samples per record you set and the clock rate you set. If you took 100 samples per record with a 100kHZ sample clock, each record takes 1 millisecond to acquire. After the device finishes a record, it will automatically re-arm and wait for the next trigger. If any triggers are received while it's acquiring or before it's re-armed, those triggers are ignored, so it is possible to only acquire data on some of your trigger pulses. You'll have to be aware of the length of time each record takes, as well as hardware re-arming time (check your devices rearm time in the data sheet).

To the second question, the timestamp is the instant in time when each record received its trigger. Absolute is the time itself, relative is the time from the first trigger (so the relative time for the first record will always be 0).

Cason

Applications Engr., NI