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Rank: Newbie
Groups: Member
Joined: 6/15/2011
Posts: 5
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I need to get the maximum and minimum of a tag for just the current day. It needs to be from 12:01 to the current time and not for the past 24 hours. Is there a way to do this; preferrably w/o using a macro?
Thanks.
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Rank: Newbie
Groups: Member
Joined: 3/4/2011
Posts: 6
Location: France
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Get the Max/Min of a tag over le last day (24h) is easy with the PI Calculation of the value object but as far as I know there is no way to get what you what without a VBA macro... Here is an example of a macro retrieving Max/Min of the SINUSOID tag : Code:Private Sub Value_DataUpdate()
Dim myPoint As PIPoint
Dim myServer As Server
Dim myPIValues As PIValues
Dim myPIValue As PIValue
If Application.RunMode Then
Set myServer = PISDK.Servers.DefaultServer
Set myPoint = myServer.PIPoints("SINUSOID")
Set myPIValues = myPoint.Data.RecordedValues("t", "*", btAuto, "", fvRemoveFiltered)
Set myPIValue = myPIValues.Summary("t", "*", astMaximum, cbEventWeightedIncludeBothEnds)
MaxText.Contents = CStr(myPIValue.Value)
Set myPIValue = myPIValues.Summary("t", "*", astMinimum, cbEventWeightedIncludeBothEnds)
MinText.Contents = CStr(myPIValue.Value)
Else
End If
End Sub This is asumming you have on your display a Value object named "Value", two Text objects named "MaxText" and "MinText" and PISDK referenced in your VBA project. Also, did you considered using PEs (Performance Equations) ? I know it's not the best solution as each PE consume a point licence ... but well, will work for sure! Hope this helps  O.
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Rank: Newbie
Groups: Member
Joined: 6/15/2011
Posts: 5
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Thanks OlJo69. I really was trying to avoid macros but it looks like I'm unable to. I wanna try two things:
1st. I tried getting the min/max of a tag value over the past 24h but te value is inaccurate. I'm not sure what all the flelds in the Pi calculation form stand for so I would appreciate someone telling me how I would do that.
2nd. I tried using our code in the macro and including the PI SDK as a reference but couldnt get past the first "Dim" statement.
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Rank: Administration
Groups: Administration
Joined: 6/20/2008
Posts: 617
Location: Cheshire, United Kingdom.
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Hello, Where are you doing this, in ProcessBook/Datalink? You could for example have a Dataset in ProcessBook with the expression: TagMax('sinusoid','t','*') This would give you the maximum for the tag 'sinusoid' starting from midnight of the current day (t = today @ 00:00) to the current time (* = current time). You could change it to a sliding 24 hour average using: TagMax('sinusoid','*-24h','*') Is this what you were after? Principal Consultant
Real-Time Data Management @ Wipro Technologies
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Rank: Administration
Groups: Administration
Joined: 6/20/2008
Posts: 617
Location: Cheshire, United Kingdom.
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Hello, Where are you doing this, in ProcessBook/Datalink? You could for example have a Dataset in ProcessBook with the expression: TagMax('sinusoid','t','*') This would give you the maximum for the tag 'sinusoid' starting from midnight of the current day (t = today @ 00:00) to the current time (* = current time). You could change it to a sliding 24 hour average using: TagMax('sinusoid','*-24h','*') Is this what you were after? Principal Consultant
Real-Time Data Management @ Wipro Technologies
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Rank: Newbie
Groups: Member
Joined: 6/15/2011
Posts: 5
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I'm using ProcessBook.
This looks like it works. Sweet! Thanks. One problem I'm still having is the Time stamp. I would like the time stamp to show the time of the Max and Min values.
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Rank: Advanced Member
Groups: Member
Joined: 4/7/2011
Posts: 137
Location: KZN, South Africa
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FindEq('tag','t','*',TagMax('tag','t','*'))
This should do the trick, let me know if it works
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Rank: Newbie
Groups: Member
Joined: 6/15/2011
Posts: 5
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squatty wrote:FindEq('tag','t','*',TagMax('tag','t','*'))
This should do the trick, let me know if it works That also worked! Thanks to all of you!
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