Monitor picoscope update intervals in streaming mode

[alexxcons]

In GitLab by @alexxcons on May 21, 2020, 17:37

How often the method "streaming_callback" is called by the picoscope cannot be set directly. The frequency seems to be defined by the chosen Timebase and sampling rate. Low sample rates will result in less frequent calls.

Since we get out UTC stamp to alligen the date in "streaming_callback", it is beneficial for us if the method is called with a high rate.

If the picked samp_rate is too slow (e.g. <10kS) the consequence is, that we cannot match all Trigger events to the related WR-Metadata any more within proper limits (currently 20ms). It is possible to decrease the block-size, in order to increase the update-rate ... though still single updates seem to be delayed by e.g. 100ms, resulting in wrong event-matching.

The current workaround is to use sampling rates of at least 2MS (with downsampling if required) in order to match events within 20ms.

Since that is very insecure (may lead to wrong samp_rates by accident), it would be good to monitor the time between the calls of "streaming_callback" and flag a dedicated error tag, e.g. "pico_slow_update" in that case.

[alexxcons]

In GitLab by @alexxcons on May 21, 2020, 17:53

Related: #53 and #28

[alexxcons]

In GitLab by @alexxcons on May 21, 2020, 17:54

changed the description