PROCESS AUTOMATION BY

GEMMA GUIDE AND BLOCK

PROGRAMMING

M. In S. Sanchez Irving

Universidad del Valle de Mexico

irving.sanchezl@uvmnet.edu

CONTENTS

• 1. Basic Concepts

• 2. GEMMA guide

• 3. GRAFCET (flow chart) and activation functions

• 4. Programming an example

• 5. Video

BASIC CONCEPTS

Basic Concepts

Basic Concepts

Basic Concepts

Basic Concepts

Basic Concepts

System/

Control Variable

Input

variable

Output

variable

Basic Concepts

System/

Control Variable

Input

variable

Output

variable

Basic Concepts

System/

Control Variable

Input

variable

Output

variable

Basic Concepts

System/

Control Variable

Input

variable

Output

variable

Basic Concepts

System/

Control Variable

Input

variable

Output

variable

Basic Concepts

Basic Concepts

GEMMA GUIDE

GEMMA guide

GEMMA guide

With energy W

ith

ou

t en

erg

y

GEMMA guide

With energy

Wit

ho

ut en

erg

y

Stop Operating

.

Defects

.

GEMMA guide

F1 Normal

Production

F2 Preparation

Sequence

F3 Ending

Sequence

F5 Verification

with order F6 Test

F4 Verification

with no order

GEMMA guide

A1 Initial state

stop

A2 Requested

end cycle stop

A3 Requested

particular state

stop

A4 Obtained stop A5 After Defect

Preparation

A6 Initial state

preparation

A7 Defined state

preparation

GEMMA guide

D1 Emergency

Stop

D2 Failure

Diagnostic

D3 Production

with failure

GEMMA guide

A6

A7

A1

A4

A5 A2 A3

F2 F3

F1

F4

F5

F6 D2 D3

D1

Process Design

• E1 General Aspects and Grafcet level 1

• E2 Select devices

• E3 Grafcet level 2

• E4 Study GEMMA states

• E5 Define GEMMA paths

• E6 Design Control Panel

• E7 Define GEMMA transitions

• E8 Final Grafcet

PLC’S LANGUAGES

GRAFCET

GRAFCET

Sn=(Sn-1*Tn-1+Sn)Sn+1

MotorA=S3+S7

Bomba=(S7+Bomba)S0

GRAFCET

Sn=(Sn-1*Tn-1+Sn)Sn+1

MotorA=S3+S7

Bomba=(S7+Bomba)S0

DISTRIBUTING STATION by Festo

Distributing Station

Distributing Station

Magazine

• Infrared sensor (A)

• Cylinder (C, FC2)

• Storage tower

Pneumatic Arm

• Double twirl movement

(FB1,FB2,B1,B2)

• Vacuum valve (V1)

• Blowing valve (V2)

Distributing Station

Distributing Station

ON

Semiautomatic Normal

Begin Emergency

Distributing Station

• Initial Conditions=Begin • FB1=TRUE, V1=V2=FALSE

• Normal process 1. AUTO=TRUE and START=TRUE

2. A=FALSE

3. B2=TRUE

4. FB2=TRUE, C=TRUE

5. FC2=TRUE, B1=TRUE

6. FB1=TRUE, V1=TRUE

7. VA=TRUE, C=FALSE

8. B2=TRUE

9. FB2=TRUE, V2=TRUE

10. IF VA=FALSE AND A=FALSE GO TO STEP 4

11. IF VA=FALSE AND A=TRUE GO TO INITIAL CONDITIONS

SOLVING PROBLEM

Solving Problem

GEMMA guide

A6

A7

A1

A4

A5 A2 A3

F2 F3

F1

F4

F5

F6 D2 D3

D1

END

STOP

AUT&ST

FB1

FB1

RESET

MANUAL

MANUAL

OPERATOR

MANUAL

FINAL GRAFCET

FINAL GRAFCET