Read from a PI Data Archive
R2026bThis example shows you how to read data from specified tags of an AVEVA® PI Data Archive.
The read capability of Industrial Communication Toolbox™ for PI provides a variety of options and flexible ways to get the data from a PI Data Archive. Running this example assumes a PI Data Archive available for connection. The PI Data Archive is capable of storing decades of real-time data from hundreds of assets. The demo tags used in this example were provided by AVEVA and can be downloaded from AVEVA sharefile.
Create Client/Server Connection and Retrieve Required Tags
Connect to the PI Data Archive using the piclient function. In this example the Windows computer name is used as the PI Data Archive name. Your situation might vary depending on the PI System configuration.
host = getenv("COMPUTERNAME");
client = piclient(host);Request a list of tags related to the asset of interest. For more detailed information see Get Started Accessing a PI Data Archive.
tagsTurbine = tags(client, Name = "OSIDemo_GU4 Turbine*")tagsTurbine = 17×1 table
"OSIDemo_GU4 Turbine.Bearing Temperature.d5939f09-48f9-5fa9-1c4a-038afc4737d5"
"OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b"
"OSIDemo_GU4 Turbine.Cooling Water Intake Temperature.02345806-6376-56a1-3520-055aaacf2af5"
"OSIDemo_GU4 Turbine.Cooling Water Output Temperature.177387e1-d1df-5f8a-24d8-77a89e5d2719"
"OSIDemo_GU4 Turbine.Cooling Water Pressure Output.80338427-9e4a-5448-3ac6-aa1c4bff0664"
"OSIDemo_GU4 Turbine.Hours Since Last Maintenance.5d33218e-5692-55c4-1db8-765aea821b7c"
"OSIDemo_GU4 Turbine.Lubricant Oil Intake Temperature.023173cc-9003-58d8-2e95-4d7ad5efcdec"
"OSIDemo_GU4 Turbine.Lubricant Oil Output Temperature.168bd614-1fc5-5323-0887-77a127fa324c"
"OSIDemo_GU4 Turbine.Lubricant Oil Pressure Output.2d8015d1-6069-59a4-0ffb-04254bd6054c"
"OSIDemo_GU4 Turbine.Oil Level.c051220f-c20e-55bb-2ec4-f9bfb5a9d9e6"
"OSIDemo_GU4 Turbine.Total Hours Running.ace91215-54c4-5a35-1cb1-78248dcb0861"
"OSIDemo_GU4 Turbine.Turbine Vibration.63f0a79e-676a-545f-3647-8579685df5f8"
"OSIDemo_GU4 Turbine.Vane Angle.7317f353-c8e4-534f-13a9-c557c81f2de5"
"OSIDemo_GU4 Turbine.Water Flow.d8d44160-1b7f-51a9-37e7-00679041f415"
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Read Latest Value of Tag
Read the most recent recorded value of a tag using the read function.
vibrationLatestTT = read(client, tagsTurbine.Tags(2))
vibrationLatestTT = 1×3 timetable
16-Feb-2024 07:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9100 Good
Read Values over Period of Time
To read values over a period of time, first define the period. For example, to read values of a tag over the last two days, use the DateRange name-value argument to specify a starting datetime and ending datetime. Set the start date to two days ago.
startDate = datetime("now") - days(2);Set the end date to now.
endDate = datetime("now");Use these to specify the starting datetime and ending datetime in your request.
vibrationTwoDaysTT = read(client, tagsTurbine.Tags(2), DateRange=[startDate,endDate])
vibrationTwoDaysTT = 7×3 timetable
15-Feb-2024 05:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8800 Good
15-Feb-2024 09:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9120 Good
15-Feb-2024 11:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8600 Good
15-Feb-2024 15:08:29 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8900 Good
15-Feb-2024 19:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8700 Good
16-Feb-2024 01:27:41 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9900 Good
16-Feb-2024 07:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9100 Good
Read All Recorded Values of a Tag
To read all recorded values of a tag, it is useful to know when data recording began. You can use the Earliest name-value argument to determine this.
vibrationEarliestTT = read(client, tagsTurbine.Tags(2), Earliest=true)
vibrationEarliestTT = 1×3 timetable
05-Nov-2023 22:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" NaN Bad
Notice the value of this tag at the earliest recorded time is a NaN. This is often the case for the first data point in a series as the PI Data Archive indicates a status of Bad for this data point upon creation. You can exclude this from your data set if desired.
This earliest data point identifies the time of the first recorded value. You can now use this information to establish a starting datetime for your request.
startDate = datetime(vibrationEarliestTT.Time(1));
Set the ending datetime to now.
endDate = datetime("now", TimeZone="local");
Depending on your system, this query may return a large amount of data. If you have an extensive history of data that makes this too slow or impractical, you may want to skip this step.
vibrationAllTT = read(client, tagsTurbine.Tags(2), DateRange=[startDate,endDate])
vibrationAllTT = 3759×3 timetable
05-Nov-2023 22:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" NaN Bad
05-Nov-2023 22:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.7500 Good
05-Nov-2023 22:50:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8900 Good
05-Nov-2023 22:53:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8800 Good
05-Nov-2023 22:59:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8500 Good
05-Nov-2023 23:00:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8400 Good
05-Nov-2023 23:05:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8600 Good
05-Nov-2023 23:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8000 Good
05-Nov-2023 23:11:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8800 Good
05-Nov-2023 23:14:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8800 Good
05-Nov-2023 23:25:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9000 Good
05-Nov-2023 23:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8100 Good
05-Nov-2023 23:42:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9900 Good
05-Nov-2023 23:50:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9800 Good
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Reduce Data Set Using Linear Interpolation Provided by PI Server
Notice the large number of datapoints in the result of the previous step. You can reduce the data set by using the Interval name-value argument. For example the following read requests data with an interval of 30 minutes. The Interval name-value argument requests the PI Server to perform linear interpolation on recorded values and provide results at the specified interval.
vibrationInterpolatedTT = read(client, tagsTurbine.Tags(2), DateRange=[startDate,endDate], Interval=minutes(30))
vibrationInterpolatedTT = 4919×3 timetable
05-Nov-2023 22:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" NaN Bad
05-Nov-2023 22:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.7500 Good
05-Nov-2023 23:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8000 Good
05-Nov-2023 23:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8100 Good
06-Nov-2023 00:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.7800 Good
06-Nov-2023 00:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9600 Good
06-Nov-2023 01:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9100 Good
06-Nov-2023 01:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.6700 Good
06-Nov-2023 02:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8800 Good
06-Nov-2023 02:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8200 Good
06-Nov-2023 03:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9900 Good
06-Nov-2023 03:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.6790 Good
06-Nov-2023 04:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.6358 Good
06-Nov-2023 04:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9452 Good
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Clean Up
When you are finished working with the PI Data Archive, disconnect and remove the client by clearing its variable from the workspace.
clear client;
