RE: Phoebus Data Browser CSV Export from Archiver, Extra Timestamp Issue

["Manoussakis, Adamandios via Tech-talk" <tech-talk at aps.anl.gov>]

Ah got it, thanks Kay for the clarification. 

 

From: Kasemir, Kay <kasemirk at ornl.gov>
Sent: Tuesday, May 4, 2021 10:27 AM
To: EPICS tech-talk <tech-talk at aps.anl.gov>; Manoussakis, Adamandios <manoussakis1 at llnl.gov>
Subject: Re: Phoebus Data Browser CSV Export from Archiver, Extra Timestamp Issue

 

That's a feature.

 

The archive stores changes​ in the value. We tend to not write the same value over and over if it didn't change.

When you plot a temperature setpoint and read back, the read back might change over time, but the setpoint  might have last been set by operators 3 weeks ago.

The plot would look silly if we don't show the setpoint, so we always start the plot with the last value at-or-before the start time as the initial value, and then draw a line until the next sample. If there is no next sample (value hasn't changed), you get a horizontal line since that value persisted all through the plot. Or you get a line that changes as the data changed.

In any case, that initial value is somewhat important, and that's why it's also included in the exported data, with the original time stamp.

 

-Kay

 

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From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Manoussakis, Adamandios via Tech-talk <tech-talk at aps.anl.gov>
Sent: Tuesday, May 4, 2021 1:15 PM
To: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: [EXTERNAL] Phoebus Data Browser CSV Export from Archiver, Extra Timestamp Issue

 

Hey All,

 

I have noticed when I use the Phoebus Data Browser to export CSV files from the Archiver, it is returning an extra timestamp that is outside the requested dates.  Has anyone else run into this and is there something I am doing wrong possibly that is causing the error?

 

For example here is the csv export start / end time

 

# Start Time : 2021-04-27 14:56:50.000

# End Time   : 2021-04-27 15:10:50.000

 

When you scroll down to the actual start of the data in the CSV the first time stamp is always not from that set (seems to always be before the start time though)

 

2021-04-26 13:25:10.665

 

Thanks,

Adam