Feature request: Get first and last recorded value of a series

[Hugovdberg]

To export interpolated values only over the time range for which values were actually recorded some helper attributes would be useful:

• PIPoint.first_recorded_value
• PIPoint.first_recorded_timestamp
• PIPoint.last_recorded_value
• PIPoint.last_recorded_timestamp

A workaround is available in the meantime:

import PIconnect as PI

start_date = PI.AFSDK.AF.Time.AFTime('01-01-1970')
end_date = PI.AFSDK.AF.Time.AFTime('*')

at_or_after_date = PI.AFSDK.AF.Data.AFRetrievalMode.AtOrAfter
at_or_before_date = PI.AFSDK.AF.Data.AFRetrievalMode.AtOrBefore

with PI.PIServer() as server:
    tags = server.search('*')
    for tag in tags:
        first_val = tag.pi_point.RecordedValue(start_date, at_or_after_date)
        last_val = tag.pi_point.RecordedValue(end_date, at_or_before_date)
        first_recorded_timestamp = first_val.Timestamp
        first_recorded_value = first_val.Value
        last_recorded_timestamp = last_val.Timestamp
        last_recorded_value = last_val.Value
        print tag.name, first_recorded_timestamp, first_recorded_value, last_recorded_timestamp, last_recorded_value

The values from this example are not cleaned up into python objects yet, but can be useful already.