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Rank: Newbie
Groups: Member
Joined: 3/10/2011
Posts: 9
Location: sept-iles
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Hi,
I have a trend of tonnage per hour on a mill.
I would like to be able to add a budgeted mill rate, and be able to modify it.
first, can i add a line to a trend that is not a tag ? like a constant value of 380.
second, can that constant value be changed ? can i have a text box in which you enter the new constant value, like 300 ?
also, is there a way for a trend to clear it self at 12h interval, at midnight it starts anew and at noon the same.
Thanks
Lespoils
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Rank: Administration
Groups: Administration
Joined: 6/20/2008
Posts: 617
Location: Cheshire, United Kingdom.
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Hello, For a constant you can either use a Dataset where the expression is just the constant number you need, or use the AF2 dataset to retrieve a constant value from an AF Attribute. With the PI Expression dataset you can use VBA code to update the expression or with the AF Attribute you could use the PI System Explorer to update the AF Attribute. Not too sure what you mean by a trend clear itself, could you explain a bit more. Principal Consultant
Real-Time Data Management @ Wipro Technologies
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Rank: Newbie
Groups: Member
Joined: 3/10/2011
Posts: 9
Location: sept-iles
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Thanks, i probly be using dataset but what's AF ?
do expression dataset have to be created in VBA or can i use VBA to modify an existing dataset ? can you show me a code sample ?
about the trend clearing itself, I only want to represent one 12h shift on the trend. So i would like that when people start their shift, the trend is clear and as the day goes it trends the mill rate. when they finish their shift and other crew comes in, i want the trend to clear itself again and only start showing data from the current shift.
is that clearer ?
thanks again
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