Teknik kontrol

(1)

Mairodi ST MT

Teknik Kontrol

(2)

Dosen : Mairodi, ST.,MT. Semester : Genap

SKS : 3 sks

Buku Referensi : Programmable Logic Controller, Penulis: James A. Rehg dan Glenn J. Sartori Jumlah Peserta Total : ………...

1. Pengantar Sistem Kontrol 2. Pengantar PLC

3. Field Devices 4. Hardware PLC

5. Driver Interface PLC 6. Mengkonfigurasi PLC

7. Software pemrograman PLC

8. Sistem Bilangan dan Sistem Memory dalam PLC 9. Logika Boolean dalam Pemrograman

10 Instruksi Bit 10. Instruksi Bit

11. timer dan Counter 12. Instruksi Matematika

(3)

1 Pengantar Sistem Kontrol

1. Pengantar Sistem Kontrol

(4)

Loop Kontrol

Jenis Pengontrol:

¾Analog dan digital

¾On-off dan PID

Controller Process

+

Actuator

¾On off dan PID

¾Feedback, Feedforward dan Cascade Control

Sensor + Sensor + Transmitter

Tujuan Pengontrolan :

– Menjaga/mempertahankan nilai besaran pada referensi tertentu – Mengatasi gangguan/efek perubahan pada sistem

(5)

Contoh-contoh pengontrol yang

Contoh contoh pengontrol yang

sering dipakai dalam industri :

• Programmable logic controller (PLC)

Mi

t

ll

DIBAHAS DALAM KULIAH INI

• Microcontroller

• DCS (Distributed Control System)

• SCADA (Supervisory Control and Data

Acquisition) System

(6)

Definition (1)

( )

• Process

– A series of interrelated actions which transform material

It covers all resources that are involved in the process and It covers all resources that are involved in the process and talks about

process “inputs” (e.g. resources, raw material) and “outputs” (e.g.

fi i h d d t)

Raw Materials Products Energies Out

finished product)

Process

Energies Out Energies Out

(7)

Definition (2)

( )

• Process Control

– To maintain desired conditions in a physical system

To maintain desired conditions in a physical system

by adjusting selected variables in the system in spite

of disturbances affecting the system and observation

noise

Corrective Action Process

(8)

Daylife Example: Driving a Car

Brain:

Daylife Example: Driving a Car

• Control Objective (Setpoint):

Maintain car in proper lane _Brain: Control calculation

Eyes: Sensor Maintain car in proper lane

• Controlled variable:

Location on the road

• Manipulated variable:

Orientation of the front wheels Orientation of the front wheels

• Actuator:

Steering wheel

• Sensor:

D i ’

Driver’s eyes • Controller: Driver • Disturbance: Steering wheel: Actuator

Curve in road

• Noise:

(9)

Industrial Example #1: Heat

Exchanger

• Control Objective (Setpoint):

Maintain temperature

Product

Stream TC Steam

Maintain temperature

• Controlled variable:

Outlet temperature of product stream

• Manipulated variable:

TT Steam flow

• Actuator:

Control valve on steam line

• Sensor:

Feed Condensate

Thermocouple on product stream

• Controller:

Temperature controller

• Disturbance:Disturbance:

Changes in the inlet feed temperature

• Noise:

(10)

Industrial Example #2: Liquid

C

Level Control

• Control Objective (Setpoint):

Maintain level Maintain level

• Controlled variable:

Fluid level in the tank

• Manipulated variable:

Fluid

Fluid flow

• Actuator:

Control valve on fluid line

• Sensor:

LC Level transmitter on the tank

• Controller:

Level controller

• Disturbance:

Disturbance:

Changes in the inlet feed flow

• Noise:

(11)

Elements of Process Control Loop

• Sensor

Elements of Process Control Loop

Measure process variable

• Transmitter

Convert the measured process variable into standard signal Convert the measured process variable into standard signal

• Controller

Drive actuator by giving an appropriate controller output signal

A t

t

• Actuator

Adjust manipulated variable based on the value of the controller output signal

• Process

(12)

Istilah-istilah (I)

Istilah istilah (I)

• Control Objective (Setpoint,

SP

)

• Controlled Variable (CV) or Process Variable (

PV

)

• Measured Process Variable (

PV

)

• Controller Output (

CO

)

• Controller Output (

CO

)

• Manipulated Variable (

MV

)

• Final Control Element (Actuator)

• Sensor/Transmitter

• Controller

• Disturbance Variable (

DV

)

• Disturbance Variable (

DV

)

• Measurement Noise

(13)

Goal of Process Operation

24 hours process operation? Hmm… I think, to achieve

Goal of Process Operation

Hmm… I think, to achieve those, we need to continuously

monitor & control the process 24 hours a day,

7 days a week!!!

• Safety & Reliability

• Product Specification

Product Specification

• Environmental Regulation

• Operating Constraint

• Efficiency

• Maximum profit

(14)

Safety and Reliability

• The control system must provide safe operation Alarms, safety constraint control, start-up and shutdown • A control system must be able to “absorb” a variety

of disturbances and keep the process in a good of disturbances and keep the process in a good operating region

Feed composition upsets, temporary loss of utilities (e g steam supply) day to night variation in the (e.g., steam supply), day to night variation in the process

(15)

Product Specification

• Quality

– Products with reduced variability

Product Specification

N C ll

– Products with reduced variability

For many cases, reduced variability products are in high demand and have high value added (e.g. feedstocks for polymers)

p u rity n tr at io n Limit p ur it y en tr atio n Limit

Old Controller New Controller

Time Im p Co n ce n Time Im p C onc e

Product certification procedures (e g ISO 9000) are

• Product certification procedures (e.g., ISO 9000) are

used to guarantee product quality and place a large

emphasis on process control

(16)

Environmental Regulation

• Various government laws may specify that the

Various government laws may specify that the

temperatures, concentrations of chemicals,

and flow rates of the effluents from a process

p

be within certain limit

Examples:

– Regulations on the amounts of SO

₂

that a

process can eject to the atmosphere, and on the

lit

f

t

d t

i

l k

(17)

Operational Constraint

• All real process have constrained inherent to

All real process have constrained inherent to

their operation which should be satisfied

throughout the operation

g

p

Examples:

– Tank should not overflow or go dry

g

y

– Distillation column should not be flooded

– Catalytic reactor temperature should not exceed

y

p

an upper limit since the catalyst will be destroyed

(18)

Efficiency

• The operation of a

process should be as

i

l

ibl

economical as possible

in utilization of raw

material, energy and

capital

p

(19)

Maximizing the Profit of a Plant (1)

• The operation of a process may many

p

y

times involves controlling against

constraints

Th

l

th t

bl t

• The closer that you are able to

operate to these constraints, the more

profit you can make

Example:

– Maximizing the product production rate usually involving controlling the process y g g p against one or more process constraints

(20)

Maximizing the Profit of a Plant (2)

Constraint control example: A reactor temperature control

Maximizing the Profit of a Plant (2)

• At excessively high temperatures the reactor will experience a temperature runaway and explode

• But the higher the temperature the greater the product yield

• Therefore better reactor temperature control allows safe operation at a

New Controller Improved Performance

• Therefore, better reactor temperature control allows safe operation at a higher reactor temperature and thus more profit

m pur it y cent rat io n _Limit m pur it y cent rat io n _Limit Im Co n c Im Co n c

(21)

The History of Process Control

• 1960s Pneumatic analog instrumentation, controllers, and computing modules • 1970s Electronic analog instrumentation controllers and computing modules

The History of Process Control

• 1970s Electronic analog instrumentation, controllers, and computing modules – Direct digital control with special algorithms programmed in main frame computer

• 1980s Electronic analog instrumentation and digital distributed control systems (DCS) – Supervisory and model predictive control configured in special purpose computers • 1990s Smart analog instrumentation, valves, and digital distributed control systemsg g y

– Supervisory and model predictive control configured in special purpose computers – Neural networks, online diagnostics, and expert systems in special purpose computers – Real time optimization using model libraries in special purpose computers

• 2000s Field bus based digital smart instrumentation, valves, and control systems

Digital bus takes full advantage of smartness and accuracy of instrumentation and valves – Digital bus takes full advantage of smartness and accuracy of instrumentation and valves – Some fast PID controllers such as flow and pressure go to the field transmitter or valve – Model predictive control, neural networks, online diagnostics, and expert systems are

(22)

Common Types of Control Strategy

• Manual vs. Automatic

• Servo vs. Regulator

• Open-loop vs. Closed-loop

• Control strategies

– Feedback Control Feedforward Control – Feedforward Control – Cascade Control

• Single-Input Single-Output (SISO) vs. Input

Multi-Output (MIMO, also known as multivariable)

(23)

Manual vs Automatic

Temperature indicator

Should I adjust h l

Manual vs. Automatic

• Manual

the valve or should I run?

– Human has to adjust the MV to obtain the desired value of the PV based on observation and

i i

Emergency cooling

prior experiences

• Automatic

– The computer (or other device) – The computer (or other device)

autonomously controls the

process and may report status back to a operator

(24)

Regulator vs Servo

Regulator vs. Servo

• Regulatory control

_{Regulatory control}

Servo control

– Follow constant

setpoint, overcoming

Servo control

• Follow the changing setpoint

7.00 AM: 80 C… 8.00 AM: 70 C… 9 00 AM: 60 C

o o o

the disturbance

75.5 C… 75.3 C… 75.4 C…

o o o

(25)

Open-loop vs Closed-loop

Open loop vs. Closed loop

• Open-loop

PV CO

Process

Decisions

C t ll

p

– Process is controlled based on predetermined scenario Ex.: When food is done in an

Controller

oven, timers on outdoor lights

PV CO

• Closed-loop

– The information from sensor

Decisions

Controller

Process

– The information from sensor is used to adjust the MV to obtain the desired value of the PV

(26)

Control Strategies (1)

• Feedback Control

C ti ti b d i bl (PV)

Control Strategies (1)

– Corrective action based on process variable (PV)

DV SP

Feedback Controller

Process

Advantage

Requires no knowledge of the source or nature of disturbances, and minimal detailed information about how the process itself works

Disadvantage

Controller takes some corrective actions after some changes occurs in process variable PV

(27)

Control Strategies (2)

• Feedforward Control

B d th t f di t b (DV) Æ f df d t ll

Control Strategies (2)

– Based on the measurement of disturbance (DV) Æ feedforward controller can respond even before any changes occurs in PV

Advantage

SP Feedforward CO PV

Controller Process

Advantage

Controller takes some corrective actions before the process output is different from the setpoint Æ theoretically, perfect disturbance rejection is possible!

Disadvantage

• Requires process model which can predict the effect of disturbance on PV • Requires process model which can predict the effect of disturbance on PV

• If there are some modeling error, feedforward control action will be erroneous (no corrective action)

(28)

Control Strategies (3)

• Feedback/Feedforward Control

– Feedforward controller will adjust CO as soon as the DV is detected – If the feedforward action is not enough due to model error,

measurement error and etc., feedback controller will compensate the

PV CO

difference

SP Feedforward/ CO PV

Feedback Controller

(29)

Control Strategies (4)

• Cascade Control

– The disturbance DV1 arising within the inner loop are corrected by the

inner controller before it can affects the PV of the outer one Example: Control valve + positioner

DV SP

DV₁

Inner loop Outer loop

CO Outer Feedback

Controller

Inner Feedback

Controller ProcessInner ProcessOuter

(30)

Control Strategies (5)

• Feedback/Feedforward + Cascade Control

Outer loop

Feedback/Feedforward + Cascade Control

CO Outer Feedback

C ll Inner Feedback Inner O ter

DV₁

Inner loop

Controller Inner Feedback

Controller ProcessInner ProcessOuter

(31)

SISO vs MIMO

SISO vs. MIMO

• Based on how many

PV

and

MV

we have in a process

DVs

SISO

MIMO

y

p

DV PV CO

Process

…

_CO Process _PV

…

Decisions

Controller

Process _COs _PVs

Decisions Process

…

Controller

(32)

Performances of Process Control System

• Closeness to setpoint

• Short transient to one setpoint to other setpoint

y

• Short transient to one setpoint to other setpoint

• Smaller overshoot and less oscillation

• Smooth and minimum changes of variable

Smooth and minimum changes of variable

manipulation

• Minimum usage of raw materials and energy

1, 2

1 2

Regulator Servo

(33)

Istilah-istilah (II)

• Manual control

Servo control

Istilah istilah (II)

• Automatic control

• Open-loop control

Servo control

Regulatory control

SISO control

MIMO control

• Closed-loop control

• Feedback control

f

MIMO control

Transient response

Overshoot

O ill ti

• Feedforward control

• Cascade control

(34)

Ringkasan

• Control has to do with adjusting manipulated

Control has to do with adjusting manipulated

variables of the process to maintain controlled

variables at desired values

• All control loops have a controller, an actuator, a

process and a sensor/transmitter

process, and a sensor/transmitter

• Various controller strategies can be realized to

hi

d

i d

bj

ti

&

d

t

achieve desired process objectives & product

specifications

(35)

Pertemuan ke-2

Pe nga nt a r PLC

Pertemuan ke 2

(36)

Sasaran Pelatihan

• Mengetahui sejarah perkembangan PLC

• Mengetahui pengontrolan dengan Relay • Prinsip dasar operasi PLC

• Mengetahui informasi umum mengenai

(37)

Sejarah Singkat Sistem Kontrol Industri

j

g

• Proses kontinyu • Sederhana

• Sinyal elektrik analog 4-20 mA • Sistem kontrol digital

• Proses kontinyu • Lebih kompleks

• Sinyal elektrik analog 4-20 mA, FF, HART

• Input output terbatas • Sistem kontrol digital • Input output banyak • Algoritma pengontrol PID

Era Pneumatic Era PLC Era DDC Era DCS

Smart Instrument FCS Electric Instrument

Tradisional Instrument

Era Pneumatic Era PLC

- Proses Diskrit S d h

• Menggantikan relay

• Sinyal digital - Sederhana

- Sinyal pneumatic 3-15 psi - Sistem kontrol

penumatik-mekanik

• Sinyal elektrik 4-20mA • Sistem kontrol digital • Input/output banyak

• Sistem kontrol yang lebih

• Sinyal digital • FF network

(38)

Direct Digital Control (DDC)

g

(

)

IBM Control Station

Controller

IBM Control Station

Apple Control Station

Traditional Signal :

4 – 20 mA

1 – 5 V Instrument Card

CV CV

Process A

(39)

Distributed Control System (DCS)

Contoh :

DCS

PLC

NI – FP

Hub – Switch

Contr

oller

Traditional Signal Semi-digital Signal Digital Signal

Industrial Comm : High Speed Data Exchange : HSE, DH+, FF, CAN

TT CV CV Spur Controller Digital Signal 0 mA Digitized :FF/DH+/CAN m A Spur TT TT

FT LT LT LT

Process A

4 – 2 4 – 20 m

(40)

Field Control System (FCS)

Computer Function :

Data logging

Supervisory Monitoring

Contoh :

NI – CAN

NI – FF

Setting Input

Programming

PLC/DCS

NI – FP

Industrial Communication Card

Contr

oller

Fully

Digital Signal Industrial Comm : High Speed Data Exchange : HSE, DH+, FF, CAN Spur TT CV CV Spur Controller Digitized :FF/DH+/CAN Spur Spur TT

Process A

Controller

(41)

Mengapa menggunakan PLC

g p

gg

• Bisa mengontrol komplet proses manufaktur

• Mencapai konsistensi dalam manufaktur

• Meningkatkan kualitas dan akurasi

B k j d l

li

k

lit/b h

• Bekerja dalam lingkungan yang sulit/bahaya

• Meningkatkan produktivitas

• Memperpendek waktu pemasaran

Memperpendek waktu pemasaran

• Menyediakan variasi produk yang lebih besar

• Dengan cepat mengubah dari satu produk ke produk

g

p

g

p

yang lain

(42)

Kemudahan dengan PLC

g

• PLC merupakan hardened industrial computer

• Sekuens kontrol PLC dengan mudah diubah dengan

pemrograman. Beberapa fungsi advance

:

• Aritmatika

• Manipulasi data

• Shift registers

• Penyimpanan dataPenyimpanan data

• Pemrograman LD menggunakan PC

• Link komunikasi dan jaringan antara PLC dan PC

(43)

Bagian-bagian PLC

g

• Bagian sensing

• Bagian input

• Controller

• Programmer

• Bagian outputBagian output

(44)

Pengontrolan di Masa Lalu

g

• Kelistrikan telah digunakan untuk mengontrol

g

• Berbasis pada relay

• Relay ini memungkinkan daya listrik men-switch on atau

off tanpa men-switch secara mekanik

(45)

Perkembangan PLC

g

• Pengembangan komputer dengan biaya rendah telah membawa

kepada revolusi teknologi yaitu teknologi PLC

• Penggunaan PLC dimulai sejak tahun 1970 an dan menjadi pilihan utama dalam pengontrolan di industri manufaktur

• Keuntungan dari PLC :g

– Efektifitas biaya dalam mengontrol sistem kompleks – Fleksibel

Kemampuan komputasi untuk kontrol canggih – Kemampuan komputasi untuk kontrol canggih

– Kemudahan dalam troubleshooting mengurangi downtime. – Komponen yang mudah didapatkan dapat beroperasi tahunan

(46)

Relay

y

• Relay digunakan untuk logika kontrol

• Relay adalah alat sederhana yang menggunakan medan magnetik y y g gg g untuk mengontrol switch

• Kontak yang menutup pada saat energized coil disebut normally open. Kontak yang menutup pada saat tidak ada energized coil p y g p p g disebut normally closed

(47)

Bagaimana Mengontrol Relay ?

g

y

Input tunggal push button

Meng-energized coil

Mendrive output relay 220V AC

(48)

(49)

Cara Kerja Program PLC

j

g

• PLC diprogram dengan teknik berdasarkan logika skema pengkabelan relay

• Daya listrik ada di sebelah kiri, garis vertikal, hot rail. • Di sebelah kanan disebut neutral rail.

N t l

I t Hot Rail

Neutral

Input

Rung Rung

(50)

PLC Connections

I O

PUMP

nput utput

Tanki

Ketika proses dikontrol, PLC

menggunakan input dari

k

b

sensor untuk membuat

(51)

Cara Kerja CPU

j

Scanning POWER ON

Loop kontrol adalah siklus

kontinyu dari pembacaan

Scanning

Input Real Input

kontinyu dari pembacaan

input PLC, memecahkan

logika LLD, kemudian

mengubah output

Scanning

Operation New

Output p

(52)

Cara Kerja PLC

Sanity Check

POWER ON

j

Error

STOP Yes

• Power On

• Men-check apakah hardware bekerja dengan benar

Error

Indikator On

Scanning

Save to

bekerja dengan benar

• Jika ada masalah PLC akan berhenti dan menyalakan indikator error No Scanning All Inputs Save to Memori

L dd

L

i S l

d

• Mulai membaca (scan) semua input

• Ladder logic akan discan (dipecahkan) menggunakan

Ladder Logic Solved

Scanning

( p ) gg

nilai input yang tersimpan tersebut.

• Output akan discan • Nilai ouput berubah

Scanning All Outputs

• Nilai ouput berubah

• Waktu yang diperlukan untuk masing-masing tahapan dalam

(53)

Konfigurasi Fisik PLC

g

• Fixed

– Terdiri dari prosesor, modul input-output, catu daya

dalam satu unit

Chassis adalah suatu tempat

• Modular

– Terdiri dari prosesor, semua

modul input-output sebagai _{Chassis adalah suatu tempat}

yang terdiri dari slot-slot…

… tempat modul I/O…

p p g

perangkat keras yang dapat dipasang dan dilepas secara terpisah

(54)

A Picture of PLC System

y

Man-Machine Interface Programming Device C

PLC Network

PLC PLC PLC PLC

(55)

Tipikal Panel Pengontrol (PLC)

p

g

(

)

(56)

PLC vs. PC

• PC

– Menerima masukan dari keyboard dan menampilkan hasil operasi program pada monitor

• PLC

– Menerima masukan dari suatu alat, seperti switch atau , p termokopel, dan menetapkan suatu keluaran, seperti

menghidupkan lampu atau menutup bukaan katup (valve), berdasarkan hasil operasi program

(57)

PLC vs. PC

• PLC didesain untuk beroperasi di lingkungan industri:

Temperatur dan kelembaban lingkungan yang fluktuatif dalam p g g y g rentang yang besar.

PLC yang didesain dengan baik tidak dipengaruhi oleh noise elektrik

elektrik.

• Hardware dan software PLC didesain sedemikian

sehingga mempermudah penggunaan oleh electrician

d

k i i

dan teknisi.

PLC diprogram dengan relay ladder logic.

PLC tampil dengan bahasa pemrograman yang dibangun dalam p g p g y g g memory permanennya,

(58)

PLC vs. PC (2)

• PC merupakan mesin komputasi yang kompleks

Mampu mengeksekusi beberapa program atau tugas secara

( )

p g p p g g

simultan dan dengan beberapa urutan

• Sedangkan PLC mengeksekusi program tunggal secara

ber r tan dan sek ensial dari instr ksi a al sampai akhir

berurutan dan sekuensial dari instruksi awal sampai akhir

• Troubleshooting dipermudah karena pada PLC sudah

didesain fault indicator/information

• Interface modular yang mengkoneksikan field device

dengan mudah dikoneksikan dan diganti.

(59)

PLC vs. PC (3)

• Software PLC yang dijalankan pada PC

dikategorikan dalam 2 hal berikut

:

( )

dikategorikan dalam 2 hal berikut

:

Software PLC yang digunakan user untuk memprogram dan mendokumentasikan

S ft PLC di k t k it d

Software PLC yang digunakan user untuk memonitor dan mengontrol proses, dikenal sebagai man machine interface

(60)

Typical Configurations for PLC

yp

g

Medium

Large

Small

(61)

Typical Configurations for PLC

• Small size

yp

g

sampai 128 I/O

memory sampai 2 KB

M di

i

• Medium size

sampai 2048 I/O

memory sampai 32 KB

• Large size

sampai 16000 I/O

memory sampai 2 MB

(62)

Tiga tipe aplikasi PLC

• Single Ended

• Multitask

C

t l

t

• Control management

A lik i SLC 500 t ll Aplikasi SLC 500 controllers: • Packaging Machinery

• Conveyors and other Material Handling Machinery

M hi T l • Machine Tools • Textile Machinery

(63)

Pertemuan ke-3

Field Devices

(64)

M easurem ent Variables

Sensors • level/volume Actuators • motors • mass • pressure • flow

AC motor

DC motor

• valves

• temperature

• status

• voltage, current

block valve

control valve

• relay g ,

• pH

• gas detector

• moisture

• buzzer

• etc

• valve positioner

(65)

Field Device Im portant A spects

Range of measurement

Operating conditions

Calibration method

Dimensions p g Accuracy Precision Linearity Age Availability

Product support

Linearity

Hysteresis

Physical characteristics

Product support (maintenance)

Spare parts

• temperature effects

• overpressure effects

• vibration effects

• humidity effects

• power supply effects

(66)

Range and A ccuracy

y

Range

• Minimum and maximum value of physics quantity that canMinimum and maximum value of physics quantity that can be measured under reference operating conditions

Accuracy

• A number or quantity that defines the limit that errors will not exceed when the device is used under reference operating conditions

• example :

± 1 o_F

± 1% of actual output reading

Reference Operating Conditions

(67)

Linearity

y

The closeness to which a curve approximates a

straight line

(a) independent linearity (b) zero-based linearity

(a) independent linearity

linearity

(b) b d (b) zero-based

(68)

Hysteresis

y

Hysteresis

The maximum difference for the same input between the upscale and downscale

output values during a full

t i h

range traverse in each direction

• hysteresis

(69)

Repeatability & Reproducibility

y

Repeatability

The closeness of agreement b f ti among a number of consecutive measurements of the output for

• the same value of the input

• under the same operatingunder the same operating conditions

• approaching from the same direction

Reproducibility

The closeness of agreement among repeated measurements of the output for :

of the output for :

• the same value of input mode

• under the same operating

(70)

Environm ent Conditions

Humidity

• Field device should be capable of operating in environments with 0-p p g 100% humidity

• Working fluid and the ambient environment should be considererd for corrosiveness

Temperature effect

• High ambient temperature on solid state electronics adversely affect component life

• Causing some electronic failures

Vibration effect

Hazardous Locations

• flammable gases or vapors

(71)

A nother Im portant Factor

Range adjustability

→ reduce the number of

Modular plug-in circuit

boards and easily accessible spare parts that have to be

kept on hand

Adjustable damping

test points → minimize field down-time

Interchangeable parts

Protective features

• Reverse polarity protection

• Current limiting

minimize spare parts inventory

Good local service and

• Lightning suppression

• Corrosive and ambient temperature control

spare parts availability

→ minimizes potential down-time

Installation consideration

• Mounting flexibility

• Easy installation

Reliability based on field experience

(72)

Field Devices Classification

Fieldbus

Digital Signaling

Fieldbus

HART

(Highway Addressable

Remote Transducer)

Analog Signaling

Conventional

(73)

Conventional Devices

Analog data (0 - 100%) is represented by analog

signal

• electrical : 4-20 mA or 1-5 V

• pneumatic :

Example :

Differential pressure transmitter (0-150 psi operating

range and 4-20 mA output)

g

p )

• 4 mA → 0 psi

• 20 mA → 150 psi

psi

mA

(

150

0 )

56 .

25

4

20

4

10 ×

−

=

−

→

(74)

Conventional Device Configuration

Point-to-point

fi

ti

configuration

Requires dedicated

wiring for each

devices

(75)

HA RT Device

Interconnects smart transmitters in a two-wire

network

Simultaneous analog and digital signaling

1200 bps data rate

Shi ld d T i t d P i (2

i

l

)

Shielded Twisted Pair (2 wire loop)

Support multivariable transmitter with the use of

HART splitter

p

Can be used as either conventional transmitter or

smart transmitter

Normally not used for control caused by low data rate

(76)

Inside a HA RT DP Transm itter

(77)

HA RT Frequency Shift Keying

y

Uses Bell202 modem

frequencies and handshakes

• ±0.5 mA variation of

conventional 4-20 mA signal

• 1200 Hz for logic 1

• 2200 Hz for logic 0

Because the average value of the FSK signal is always zero, the 4–20 mA analog signal is not affected.

The digital signal has a response time of

Simultaneous transmission of analog and digital signal

approximately 2–3 data updates per second

(78)

HA RT Point

HA RT Point-

-to

to-

-point

point

4–20 mA signal is used to

communicate one process i bl

variable

Additional process variables, configuration parameters, and other device data are

other device data are transferred digitally for

• operations

• commissioning

• maintenance

• diagnostic

The 4–20 mA analog signal can b d f t l i th l be used for control in the normal way.

(79)

HA RT M ulti

HA RT M ulti-

-drop

drop

Requires only a single pair of wires and, if applicable,

safety barriers and an

auxiliary power supply for up to 15 field devices

All process values are transmitted digitally.

All field device polling

Used for supervisory control

addresses are >0

The current through each device is fixed to a minimum installations that are widely

spaced, such as pipelines, custody transfer stations,

(80)

M ulti

M ulti-

-m aster System

m aster System

y

Allows two masters (primary and secondary) to :

• communicate with slave devices

• provide additional operational flexibility.

Ensures interoperablility among devices through

i l d

The use of common tools for

universal commands

Enable hosts to easily access and communicate th t

products of different vendors minimizes the amount of

equipment and training

needed to maintain a plant _{the most common}

parameters used in field devices.

(81)

HA RT A dvantages

Improved plant operation

• Cost saving in comissioningg g

• Improved quality of measurement

• Cost saving in maintenance

Operational flexibility

Instrumentation investment protection

• compatibility of HART revision

• backward compatibility

• open system connection

(82)

Fieldbus Device

Devices are configured in a 2 wire network

31 25 Kbps 1 Mbps and 2 5 Mbps data rate

31.25 Kbps, 1 Mbps, and 2.5 Mbps data rate

Analog/digital data is sent as digital signal

Data communication within devices is conformed to a

standard protocol (Foundation Fieldbus or Profibus)

Based on microprocessor and embedded system

t

h

l

technology

Allows point-to-point or multi-drop configuration

Simplified wiring drawings and easier control

Simplified wiring, drawings, and easier control

engineering

(83)

Inside a Fieldbus Transm itter

HARDWARE

Medium Attachment Unit (MAU) comprises the circuit needed to connect the

device to the actual bus wires

wires.

Microprocessor

A/D converter

Sensor converts the

SOFTWARE Si l diti i

Sensor converts the physical phenomenon change into electric signal

• Conventional

Signal conditioning

Transducer block

• diagnostics

• calibration

• Silicon-based

• calibration

Function block

(84)

Inside a Fieldbus Control Valve

HARDWARE

Medium Attachment Unit (MAU)

Microprocessor

D/A and A/D converter

Electric to pneumatic converter (E/P) provide

pressure signal to modulate actuator

SOFTWARE

P iti d f ti

actuator

Mechanical to electric

transducer (M/E) to monitor actuator position

Positioner and servo function

Transducer block : diagnostics and calibration

Function block

• high/low/rate of change limits

(85)

Fieldbus Device Configurations

(86)

Num ber of Connected Devices

(87)

W iring Com parison

(88)

Fieldbus Devices A dvantage

Reduced installation cost

• wiringwiring

• terminators

• I/O cards t l l

• control panel space

Improved quality of measurement

Distributed control design

Interoperability

Online diagnostics, troubleshooting and calibration

g

,

g

Open system connection

: seamless integration

(89)

P t

k 4

PLC

PLC’s

’s H a rdw a re

H a rdw a re

Pertemuan ke-4

PLC

(90)

Sa sa ra n Pe la t iha n

Menyusun dan menggambarkan fungsi dari PLC dari

komponen-komponen hardware yang digunakan

p

y

g

Mendeskripsikan rangkaian elektrik dasar dan aplikasinya

untuk diskrit dan analog modul

Menginterprestasikan tipikal I/O dan spesifikasi CPU

Menjelaskan addresing I/O

Menggambarkan secara umum kelas dan tipe komponen

memori PLC

Menyusun dan menggambarkan tipe-tipe berbeda dari

y

gg

p

PLC peripheral yang mendukung dan tersedia

(91)

Ba gia n I /O(1 )

g

( )

Antarmuka Input dan output dianalogikan sebagai indra bagi otak PLC yaitu CPU

Bagian I/O terdiri dari I/O Chassis dan individual modul

CPU

I/O Modul di Chassis I/O Modul di Chassis

1 2 3 4 5 6 7

Power Supply

Chassis/Rack

(92)

Ba gia n I /O(2 )

g

( )

(93)

I /O Cha ssis(1 )

( )

AB SLC5/05 sistem 1746 merupakan sistem modular.

• Memerlukan sebuah 1746 I/O chassis untuk memuat beberapa modul.

• Chassis tersedia dalam beberapa ukuran slot modul 4, 7, 10 dan 13.

• Backplane menyediakan bagian komunikasi di antara modul-modul I/O dengan modul prosesor ataupun modul I/O adapter.

(94)

I /O Cha ssis(2 )

( )

(95)

I /O Cha ssis(3 )

( )

(96)

Spe sifik a si I /O Cha ssis

p

(97)

Pow e r Supply

pp y

(98)

I /O M odule a nd Cha nne l Addre ssing

g

Digunakan untuk memetakan input/output channel pada

i i d l

masing-masing module

Setiap jenis PLC dari vendor yang berbeda mempunyai k kh d l

kekhususan dalam

mengindetifikasi alamat-alamat channel di masing-masing

module module

(99)

I nput da n Out put Addre ssing unt uk PLC SLC5 /0 5

Alle n Bra dle y (1 )

y ( )

Output Input

Modul : 1 Modul : 2

O:000 O:001

I:000 I:001 Modul : 3

Modul : 4

O:002 O:003

I:002 I:003 Modul : 5

Modul : 6

O:004 O:005

I:004 I:005 Modul : 7 O:006

8 Words

I:006

(100)

I nput da n Out put Addre ssing unt uk PLC SLC5 /0 5

Alle n Bra dle y (2 )

y ( )

Octal numbering system Æ PLC 5 AB

Alamat modul I:00

0 1 2 3 4 5 6 7 10 11 12 13 14 15 16 17

Alamat Channel

O:00

(1)

¾ COS

¾ TAN

¾ ASN

¾ ACS

¾ ATN

D.4 PERCOBAAN

a) Buatlah program sederhana yang menggunakan blok CPT b) Buatlah program sederhana yang menggunakan blok ADD c) Buatlah program sederhana yang menggunakan blok SUB d) Buatlah program sederhana yang menggunakan blok MUL e) Buatlah program sederhana yang menggunakan blok DIV f) Buatlah program sederhana yang menggunakan blok SQR g) Buatlah program sederhana yang menggunakan blok NEG h) Buatlah program sederhana yang menggunakan blok SIN i) Buatlah program sederhana yang menggunakan blok COS j) Buatlah program sederhana yang menggunakan blok TAN

k) Buatlah program sederhana yang menggunakan blok ASN,ACS,ATN. l) Buatlah program sederhana yang menggunakan blok XPY.

m) Buatlah program sederhana yang menggunakan blok LOG, LN n) Buatlah program sederhana yang menggunakan blok SCP o) Buatlah program sederhana yang menggunakan blok ABS

p) Buatlah program sederhana sesuai yang ditugskan dosen di laboratorium

D.5 TUGAS LAPORAN

Buatlah laporan akhir sesuai prosedur yang telah disepakati dengan dosen yang bersangkutan

(2)

E. MODUL V

INSTRUKSI PERBANDINGAN DAN KONVERSI

E.1 TUJUAN

a) Praktikan memahami prinsip-prinsip instruksi perbandingan dan konversi b) Praktikan bisa menggunakan instruksi perbandingan dan konversi dalam

program sederhana

E.2 ALAT PERCOBAAN a) Komputer PC

b) RSLogix Emulate500 c) RSLinx

d) RSLogix500

e) PLC SLC500(jika ada)

f) Kabel serial dan UTP normal atau cross

E.3 DESKRIPSI

PLC memiliki kemampuan untuk melakukan komparasi antara dua variabel lalu membuat keputusan atas komparasi tersebut. Macam-macam komparasi adalah

¾ LIM

¾ MEQ

¾ EQU

¾ NEQ

¾ LES

¾ GRT

(3)

¾ GEQ

LIM(limit test) digunakan untuk mengetahui apakah suatu nilai berada pada range batas atas dan batas bawah yan ditetapkan, bila berada dalam range ini, maka logic continuity akan bernilai 1.

EQU(equal) digunakan untuk mengetahui apakah suatu variabel nilainya sama dengan nilai variabel lainnya, bila sama maka logic continuity bernilai 1. sedangkan MEQ(masked equal) digunakan seperti EQU, Cuma pada MEQ difilter nilai-nilai tertentu saja yang dibandingkan. NEQ(not equal) digunakan untuk mengetahui apakah suatu variabel nilainya tidak sama dengan nilai variabel lainnya, bila tidak sama maka logic continuity nya bernilai 1. LESS(less than) digunakan dalam perbandingan kurang dari. GRT(greater than) digunakan untuk perbandingan lebih dari. LEQ(less than or equal to) digunakan untuk perbandingan lebih kecil atau sama dengan. GEQ(greater than or equal to) digunakan untuk perbandingan lebih besar atau sama dengan.

Instruksi konversi digunakan untuk mengubah suatu variable dari satu bentuk ke bentuk yang lain. Misalnya dari BCD(binary coded decimal) ke biner, atau sebaliknya. Lalu mengubah dari satuan derajat ke satuan radian atau sebaliknya.

E.4 PERCOBAAN

a) Buatlah program sederhana yang menggunakan instruksi LIM b) Buatlah program sederhana yang menggunakan instruksi LES c) Buatlah program sederhana yang menggunakan instruksi GRT d) Buatlah program sederhana yang menggunakan instruksi LEQ e) Buatlah program sederhana yang menggunakan instruksi GEQ f) Buatlah program sederhana yang menggunakan instruksi EQU g) Buatlah program sederhana yang menggunakan instruksi MEQ h) Buatlah program sederhana yang menggunakan instruksi NEQ i) Buatlah program sederhana yang menggunakan instruksi TOD j) Buatlah program sederhana yang menggunakan instruksi FRD k) Buatlah program sederhana yang menggunakan instruksi DEG

(4)

l) Buatlah program sederhana yang menggunakan instruksi RAD

m) Buatlah program sederhana yang ditugaskan oleh dosen di laboratorium

E.5 TUGAS LAPORAN

Buatlah laporan akhir sesuai prosedur yang telah disepakati dengan dosen yang bersangkutan

(5)

F. MODUL VI

PENGONTROLAN VARIABEL ANALOG

F.1 TUJUAN

a) Praktikan memahami prinsip-prinsip pengontrolan variabel analog menggunakan PID

b) Praktikan memahami pengaruh masing-masing komponen pada PID c) Praktikan bisa menggunakan blok PID dalam program PLC

F.2 ALAT PERCOBAAN a) Komputer PC

b) RSLogix Emulate500 c) RSLinx

d) RSLogix500

e) PLC SLC500(jika ada)

f) Kabel serial dan UTP normal atau cross

F.3 DESKRIPSI

Di industri proses terdapat banyak sekali variabel-variabel analog yang harus dikontrol, seperti temperatur, pressure, flow, level, komposisi, pH, dan lain-lain. Agar tujuan proses tercapai maka variabel proses ini harus dikondisikan pada harga tertentu. Untuk mengendalikan variabel proses ini dibutuhkan algorima kontrol, yang sampai saat ini banyak digunakan di lapangan adalah PID, yang merupakan singkatan dari proportional integral derivative. Masing-masing term ini memiliki efek yang spesifik terhadap controller outputnya. Proportional memiliki efek yang sebanding dengan besarnya error. Integral bersifat menghilangkan error, derivative berisifat cepat dan memberi energi ekstra di awal. Kenyataan di lapangan tiga term ini digunakan dengan kombinasi. Seperti P only, PI, PD, PID. Kebanyakan di lapangan menggunakan PI, sedangkan untuk proses yang lambat digunakan unsur

(6)

derivative nya menjadi PID. Parameter-parameter PID haruslah tepat supaya pengontrolan stabil. Pemilihan parameter PID ini disebut tuning.

F.4 PERCOBAAN

a) Buatlah program sederhana yang menggunakan PID b) Ubahlah parameter P, dan lihat dampaknya

c) Ubahlah parameter I, dan lihat dampaknya d) Ubahlah parameter D, dan lihat dampaknya

e) Buatlah program yang ditugaskan oleh dosen di laboratorium

F.5 TUGAS LAPORAN

Buatlah laporan akhir sesuai prosedur yang telah disepakati dengan dosen yang bersangkutan