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UCAAT 2013, 23rd October, Paris

Test Automation in Industrial Automation

Barath Kumar

inIT – Institute of Industrial Information Technologies, Lemgo, Germany

Shiraz Gilani

Fraunhofer IOSB-INA , Anwendungszentrum Industrial Automation

Lemgo, Germany

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Why test automation is required in

Industrial automation

Due to problems in conventional manual testing:

• Cost intensive

• Requires high effort

• Unproductive (time consuming)

• Often inadequate (error prone)

• Low coverage

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Objective

To test :

• new control software of Programmable logic controllers (PLC)s

• modified PLC logic

• migrating Systems

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Test setup

PLC

PLC

PLCI/O

I/O

Plant

Profinet

ProfiBus

PLC

PLC

Profinet

I/O

I/O

Unit under

Test

Manufactoring Automation setup

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PLC

PLC

PLCI/O

I/O

Plant

Profinet

ProfiBus

PLC

Profinet

I/O

I/OInput

Output

Test setup

Manufactoring Automation setup

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PLC

PLC

PLCI/O

I/O

Plant

Unit Under Test (UUT)

PLC

I/O

Signals

Environment

Profinet

ProfiBus

Programmed using

conventional PLC

languages e.g. IEC

61131, C, etc.

Test setup – Hardware in the the loop

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Case study:

Lemgo Model Factory (LMF)

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Industrial automation environment

gateway

PLCs

fieldbus IO device Production

modules

Process behavior Network behavior

Conveyor

belt

Hybrid

module

(Robot)

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Industrial automation environment

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Industrial automation environment

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• Hybrid system nature

• Non-deterministic

• Timed nature (real-time systems)

Industrial automation complexities

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Pilot project: test focus

To identify:

• Logical Errors

• e.g. if a funnel is blocked , does the PLC stop the conveyor belt?

• Timing Errors

• e.g. if a funnel is blocked, does the PLC stop the conveyor in the pre-defined duration?

• Plant Errors

• e.g. if a sensor is broken can the PLC still handle the plant appropriately

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Pilot project framework

Model

(Commercial tool)

Industrial

Automation

Adapter

(Our software)

Test Suite

Test

Execution

Engine

(Our Software)

Test Generation

(Commercial tool)

FieldbusPLC

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Model

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Model

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Actuators signals

Sensor signals

Model

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Commercial tool generated test cases

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Adapted test cases

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Test execution

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Test verdict

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Logical errors - results

Module ID Inserted Errors Detected Errors

1 24 16

2 24 14

3 42 27

4 88 53

5 36 22

6 122 108

7 48 34

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Timing errors - results

Module ID Error Log

Correctly detected errors : 287

1 to 7 Undetected errors :

36

False detection : 51

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Plant errors - results

Module ID Inserted Errors Detected Errors

1 10 4

2 11 4

3 14 6

4 3 0

5 10 4

6 46 17

7 11 5

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I am done !