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1 DevNet Unplugged 2002 “Express Your Innovations” Build a Strong Foundation PI Server Applications Martin Jetté, OSI Developers Network Copyright © 2002 OSI Software, Inc. All rights reserved.

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2 DevNet Unplugged 2002 “Express Your Innovations” PI UDS Server Side Calculation Applications PI Performance Equations PI Totalizer PI Alarm PI Real Time SQC PI Batch

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3 DevNet Unplugged 2002 “Express Your Innovations” Why use server Apps for Calculations Keeps a history of calculations and alarms Calculation are centrally maintained Everybody can make decisions based on the same metrics Calculated data is available to all PI client tools and other systems (example: maintenance system) Possibility to do Event based calculations rather than Time based (Computations based on grade and products) Reduce calculation and network load => Calculate once and archive rather than recalculate every time a user opens a spreadsheet or dataset

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4 DevNet Unplugged 2002 “Express Your Innovations” PI Totalizer Subsystem PI includes a powerful and flexible post-processor engine that you can use to create totalizations and other simple calculations. The PI Totalizer subsystem calculates the following types of summaries: total, average, minimum, maximum, range, standard deviation and median. PI Totalizer can also calculate time that a condition is true and it can counts events. Many options are available for sampling, filtering and reporting (sending data) to PI. The PI Totalizer subsystem aggregates data from the PI Snapshot table rather than the archives (like PI PE). This can results in more precise calculations.

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5 DevNet Unplugged 2002 “Express Your Innovations” PI Totalizer vs PI Performance Equations

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6 DevNet Unplugged 2002 “Express Your Innovations” PI Compression Test Parameters: CompDev = 0.06 O C, CompMax = sec, Compmin = 60 sec 0.12

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7 DevNet Unplugged 2002 “Express Your Innovations” Compression (Result) Back

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8 DevNet Unplugged 2002 “Express Your Innovations” Configuration properties of a PI Totalizer Tag

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9 DevNet Unplugged 2002 “Express Your Innovations” ReportMode Running Identical to Ramping except the timestamp of the totalized tag stays at second after the start of the totalization period. (Stair Case) Ramping Behaves like an accumulator that increases its value every time a new Snapshot value is read from the SourceTag. (Saw Tooth) PeriodEnd No output reported until the end of the period RunEstimate The value is an estimate of the result if the rate point were to hold steady at its current value. RunEst2 The value is an estimate of the result if the rate point were to hold steady at the current average since the beginning of the accumulation interval.

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10 DevNet Unplugged 2002 “Express Your Innovations” Totalizer – Running and Ramping Current Period Period -1Period -2 Snapshot Values Archived Values Current Period Period = 5m

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11 DevNet Unplugged 2002 “Express Your Innovations” Totalizer – RunEstimate and RunEst2 Period -1 Current Period Period -2 Period -1 Current Period Period -2 Period = 5m RunEstimate => Estimated result at Period End if the value is maintained RunEst2 => Estimated result of Totalization at Period End if the current average is maintained Period -1Period -2 Period -1 Current Period Period -2 Period = 5m Current Period Estimate in time 3

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12 DevNet Unplugged 2002 “Express Your Innovations” Totalizer - PeriodEnd Period -1Period -2Current Period Keeps the same Value until the End of the period Period = 5m

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13 DevNet Unplugged 2002 “Express Your Innovations” Time and Event Counting EventEQ and EventNE make comparisons to the value of the CompValue field. Use CalcMode of TimeTrue to count the number of seconds the SourceTag has the value specified in the Function field (i.e., EventEQ, EventNE etc.).

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14 DevNet Unplugged 2002 “Express Your Innovations” PI Performance Equations Allows for the configuration of server based calculations –Access to all PI tags –Access to Snapshot and archived data –Advanced math and archive functions –Access PI Steam tables –Calculation can be event based and scan based

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15 Calculation expressions Mathematical Operators: + - * / ('sinusoid')/2 + ('flow.pv'-100) Functions: abs(), atn()BoD(), BoM() cos(), sin(), tan()exp(), e ( ), log() int(), sgn(), sqr()concat(), mid(), Ltrim() Relational Operators, =, <>, = Logical Operators And, Or, Not : ('sinusoid' > 50 and 'flow.pv' > 90) Advanced If …Then …Else, curve(), arma() TimeGT, FindLT, TagMax, TagAvg, String management …

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16 DevNet Unplugged 2002 “Express Your Innovations” PI PE ReCalculator PI Recalc module can update the calculations when historical data is modified, added, deleted or delayed to the PI archive Example – Scan based calculation => Tagavg('Sinusoid','*-30m','*',0) 11h30 12h00 1- Archive event is inserted 2- Average value is affected 3- Average value is recalculated

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17 DevNet Unplugged 2002 “Express Your Innovations” PI PE Recalc Example – Events based calculation => ('PointA' + 'PointB') 1- New value added to the archive 2- A new value is calculated 3- Dependent values are also recalcultated Source 1 (Point A) Source 2 (Point B) Calculation result

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18 DevNet Unplugged 2002 “Express Your Innovations” PI Alarm Subsystem The alarm subsystem provides the ability to generate and manage alarms for PI points. PI Alarm is designed to supplement, not replace, the alarm capabilities available from plant control systems. Because PI is frequently used to integrate data from different sources, PI is often used to perform calculations using variables from multiple physical locations or systems. Types of alarms supported –Above or below alarm limits (4 levels) –Equal or different to a certain digital state or string –Rate of change Keeps historical alarm information in PI tags (Alarm conditions, acknowledgment and alarm statistics)

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19 DevNet Unplugged 2002 “Express Your Innovations” PI Alarm Subsystem Features Alarm Priorities: Alarms can be organized and prioritized via 3 priority levels –1=Alert, 2=Important, 3=Most Urgent Acknowledgement status: Alarms can be in one of 3 states: –New, Acknowledged, NotAcknowledged (Missed) Alarm Deadband: It is possible to set a threshold for an alarm to go back to Normal state –Example: HI alarm set 80, Deadband=2 => The value of a PI tag must be 78 or below to remove a high alarm condition Alarm Delay: It is possible to set an Alarm delay –Example: HI Alarm set to 80, delay set to 10 min => The value of the source tag must be above 80 for a period of 10 minutes in order to become in Alarm

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20 DevNet Unplugged 2002 “Express Your Innovations” PI Alarm Dataflow

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21 DevNet Unplugged 2002 “Express Your Innovations” PI Alarm View client PI AlarmView exposes Activex controls that can be used in other Applications for example PI ProcessBook.

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