fieldbus tutorial part 12 - advanced functionality

Advanced Functionality

[File Name or Event]Emerson Confidential27-Jun-01, Slide 2

Agenda

Process Variability

Commissioning PID

[File Name or Event]Emerson Confidential27-Jun-01, Slide 3

Impact of Reduced Process Variability

Feedstock and Scrap Cost

Productivity

Product Quality

Operating Average ShiftHard Spec.Limit

OperatingAverage

[File Name or Event]Emerson Confidential27-Jun-01, Slide 4

Statistical Process Monitoring

[File Name or Event]Emerson Confidential27-Jun-01, Slide 5

Statistical Process Monitoring

[File Name or Event]Emerson Confidential27-Jun-01, Slide 6

Measurement of Process Variability *

“Capability”

Only Random

or Short Term

Variability

“Total”: All Data

Including Short

and Long Term

Variability

Time

Process

Value

Reference: ‘Achieving Workd Class Manufacturing through

Process Control’ by Joseph Shunta, Dupont, 1995*

[File Name or Event]Emerson Confidential27-Jun-01, Slide 7

( )

( )12

Xn

2i

2

1i

-

-

=

=

-

n

X

Si

cap

( )

1

1

2

-

-

=

=

n

XX

S

n

i

i

tot

Variability Indicators May be Added To Fieldbus Devices

Total and Capability Standard Deviation is Calculated by I/O and

Control Blocks

[File Name or Event]Emerson Confidential27-Jun-01, Slide 8

Calculation Should be Done at The Fieldbus Device

2.5

2

1.5

1

0.5

0

0 1 2 3 4 5

Stot

SPI

SPID

SLQ

ST/

Ratio of process time constant to sample

time

Source: World Class Manufacturing Through Process Control

[File Name or Event]Emerson Confidential27-Jun-01, Slide 9

Block Parameters for Total and Capability Standard Deviation

[File Name or Event]Emerson Confidential27-Jun-01, Slide 10

Status Indicates: Quality (Good, Uncertain, Bad)

Reason (Device Failure, Sensor Failure, etc.)

Limit (not limited, high limited, Low Limited)

Detecting Abnormal Conditions in Input Blocks

[File Name or Event]Emerson Confidential27-Jun-01, Slide 11

Status Indicates: Quality (Good, Uncertain, Bad)

Reason (Device Failure, Sensor Failure, etc.)

Limit (not limited, high limited, Low Limited)

Detecting Abnormal Conditions in Output Blocks

[File Name or Event]Emerson Confidential27-Jun-01, Slide 12

Status Indicates: Quality (Good, Uncertain, Bad)

Reason (Device Failure, Sensor Failure, etc.)

Limit (not limited, high limited, Low Limited)

Detecting That Control is Limited by Downstream Conditions

[File Name or Event]Emerson Confidential27-Jun-01, Slide 13

Mode Attribute: Target (Operator Requested Mode)

Actual (Mode of operation)

Normal (The designed Mode)

Permitted( Modes that may be selected)

Detecting Incorrect Mode of Operation

[File Name or Event]Emerson Confidential27-Jun-01, Slide 14

Host May Utilize Mode, Status and Statistics

[File Name or Event]Emerson Confidential27-Jun-01, Slide 15

Agenda

Process Variability

Commissioning PID

[File Name or Event]Emerson Confidential27-Jun-01, Slide 16

DistributedApproach

Limited Sample Rate,

Delay/Variation

introduced by

Communications

Traditional,CentralizedApproach

Control &Autotuning

/control & Autotuning

Structuring Control For A Distributed Environment

[File Name or Event]Emerson Confidential27-Jun-01, Slide 17

Application Used For Tuning in Field Device