Read from a PI Data Archive
This 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.
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
Tags
___________________________________________________________________________________________
"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"
"OSIDemo_GU4 Turbine.Water in Oil.c0265ea0-2233-5149-3ede-44d9c5737833"
"OSIDemo_GU4 Turbine.Water pH Intake.c3355c67-ace0-557b-382e-b670d80b823a"
⋮
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
Time Tag Value Status
________________________ ____________________________________________________________________________ _____ ______
16-Feb-2024 07:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.91 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 pair 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
Time Tag Value Status
________________________ ____________________________________________________________________________ _____ ______
15-Feb-2024 05:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.88 Good
15-Feb-2024 09:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.912 Good
15-Feb-2024 11:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.86 Good
15-Feb-2024 15:08:29 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.89 Good
15-Feb-2024 19:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.87 Good
16-Feb-2024 01:27:41 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.99 Good
16-Feb-2024 07:34:53 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.91 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 pair to determine this.
vibrationEarliestTT = read(client, tagsTurbine.Tags(2), Earliest=true)
vibrationEarliestTT=1×3 timetable
Time Tag Value Status
________________________ ____________________________________________________________________________ _____ ______
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
Time Tag Value Status
________________________ ____________________________________________________________________________ _____ ______
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" 0.75 Good
05-Nov-2023 22:50:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.89 Good
05-Nov-2023 22:53:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.88 Good
05-Nov-2023 22:59:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.85 Good
05-Nov-2023 23:00:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.84 Good
05-Nov-2023 23:05:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.86 Good
05-Nov-2023 23:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8 Good
05-Nov-2023 23:11:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.88 Good
05-Nov-2023 23:14:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.88 Good
05-Nov-2023 23:25:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.9 Good
05-Nov-2023 23:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.81 Good
05-Nov-2023 23:42:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.99 Good
05-Nov-2023 23:50:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.98 Good
06-Nov-2023 00:04:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.96 Good
06-Nov-2023 00:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.78 Good
⋮
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 pair. For example the following read requests data with an interval of 30 minutes. The Interval
Name-Value pair 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
Time Tag Value Status
________________________ ____________________________________________________________________________ _______ ______
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" 0.75 Good
05-Nov-2023 23:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.8 Good
05-Nov-2023 23:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.81 Good
06-Nov-2023 00:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.78 Good
06-Nov-2023 00:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.96 Good
06-Nov-2023 01:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.91 Good
06-Nov-2023 01:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.67 Good
06-Nov-2023 02:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.88 Good
06-Nov-2023 02:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.82 Good
06-Nov-2023 03:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.99 Good
06-Nov-2023 03:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.67902 Good
06-Nov-2023 04:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.63579 Good
06-Nov-2023 04:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.94517 Good
06-Nov-2023 05:10:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.20893 Good
06-Nov-2023 05:40:42 UTC "OSIDemo_GU4 Turbine.Bearing Vibration.f60c59bb-f918-5421-12f0-40939fa38b0b" 0.70928 Good
⋮
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;