Safety Application Example

GuardLogix Pneumatic Safety Control

Networked Example Safety Rating: Category 4 per EN954-1, Designated Architecture Category 4 per ISO 13849-1:2006

TUIntroduction UT ..............................................................................................1 TUImportant User Information UT.....................................................................2 TUGeneral Safety Information UT .....................................................................3 TUDescriptionUT ...............................................................................................3 TUSetup and WiringUT .....................................................................................4 TUConfigurationUT ...........................................................................................4 TUProgrammingUT............................................................................................6 TUPerformance Data UT ....................................................................................7 TUAdditional Resources UT ..............................................................................7

TIntroductionT The purpose of this application example is to show how to wire,

configure and program a GuardLogix safety controller with a DM2

Crossflow SERPAR Double Valve from Ross Controls. A Guard I/O

module monitors the state of the pneumatic valve, which has two valve

elements independently controlled by two solenoid pilots.

Features and Benefits

• Category 4 air dump / release application may be integrated with

other safety applications using GuardLogix controllers and

Guard I/O modules

• Pneumatic valve lockout if asynchronous movement of valve

elements occurs during actuation or de-actuation

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Important User Information Solid state equipment has operational characteristics differing from those

of electromechanical equipment. Safety Guidelines for the Application,

Installation and Maintenance of Solid State Controls (publication

HTUSGI-1.1 UTH available from your local Rockwell Automation sales office or

online at HTUhttp://literature.rockwellautomation.comUTH) describes some

important differences between solid state equipment and hard-wired

electromechanical devices. Because of this difference, and also because

of the wide variety of uses for solid state equipment, all persons

responsible for applying this equipment must satisfy themselves that

each intended application of this equipment is acceptable.

In no event will Rockwell Automation, Inc. be responsible or liable for

indirect or consequential damages resulting from the use or application

of this equipment.

The examples and diagrams in this manual are included solely for

illustrative purposes. Because of the many variables and requirements

associated with any particular installation, Rockwell Automation, Inc.

cannot assume responsibility or liability for actual use based on the

examples and diagrams.

No patent liability is assumed by Rockwell Automation, Inc. with respect

to use of information, circuits, equipment, or software described in this

manual.

Reproduction of the contents of this manual, in whole or in part, without

written permission of Rockwell Automation, Inc., is prohibited.

Throughout this manual, when necessary, we use notes to make you

aware of safety considerations.

Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss.

Identifies information that is critical for successful application and understanding of the product.

Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.

Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage may be present.

Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach dangerous temperatures.

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General Safety Information

This application example is for advanced users and assumes that you are trained and experienced in safety system requirements.

A risk assessment should be performed to make sure all task and hazard combinations have been identified and addressed. The risk assessment may require additional circuitry to reduce the risk to a tolerable level. Safety circuits must take into consideration safety distance calculations which are not part of the scope of this document.

Contact Rockwell Automation to find out more about our safety risk

assessment services.

TDescriptionT Many machine designers use both electricity and pressurized air as

energy sources for machine movement. These energy sources can

produce hazards to the machine operator and other users of the machine,

and must be appropriately controlled.

This application note provides an example of how to integrate electrical

safety into pneumatic safety. The three main devices in this application

example are the GuardLogix safety controller, the CompactBlock Guard

I/O module, and the DM2 Crossflow pneumatic safety valve

manufactured by Ross Controls.

Safety Function

This example contains a safety device (like an emergency stop

pushbutton) that is monitored by the Guard I/O module and GuardLogix

safety controller. The GuardLogix and safety I/O module controls a

redundant and self-monitored pneumatic valve.

Example Bill of Material

This application example uses these components.

Catalog Number Description Quantity

1756-L62S GuardLogix safety controller 1

1756-LSP GuardLogix safety partner controller 1

1756-A4 4 slot chassis 1

1756-PA73 ControlLogix power supply 1

1756-ENBT/A Ethernet module 1

1791ES-IB8XOBV4 CompactBlock safety I/O module with 8 safety inputs 4 safety bipolar outputs

1

DM2CNA42A21 DM2 Crossflow SERPAR Double Valve, ½ in. valve port size

1

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Setup and Wiring

For detailed information on installing and wiring, refer to the product

manuals listed in the Additional Resources on page X7X.

TConfigurationT Follow these steps to add the 1791ES-IB8XOBV4 safety module to your

GuardLogix project:

1. Open your RSLogix 5000 project.

2. Add the 1791ES-IB8XOBV4 module to your I/O Configuration:

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3. Configure the 1791ES-IB8XOBV4 module as shown.

Input Configuration Tab

Test Output Tab

Output Configuration Tab

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TProgrammingT Program your safety application code within the safety task of your

RSLogix 5000 project.

Create application code as shown.

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TPerformance DataT The typical sequence of operation is described below.

1. The operator determines that the system is not operating properly.

2. The operator presses the E-stop button.

Output pressure goes to zero.

3. The operator releases the E-stop.

Output pressure is at zero.

4. The operator presses Circuit Reset.

Output pressure goes to 35 psi.

5. An open-wire fault is detected on the channel 1 valve.

Pressure goes to zero and air is directed to the exhaust.

If the channel 2 valve is opened so that both valves are now open and

the circuit is reset, the air stops going through the exhaust and the

output pressure remains at zero. If valve 1 then closes, the air goes

back through the exhaust. The valve must be reopened and the circuit

reset to stop losing air. Both valves must close simultaneously for the

output pressure to go to 35 psi.

To properly correct the fault, follow these steps.

a. Open the other valve.

b. Press circuit reset to clear the fault.

c. Press circuit reset again to close both valves simultaneously

(within 120ms).

TAdditional ResourcesT For more information about the products used in this example, refer to

these resources.

Resource Description

GuardLogix Controllers Users Manual, publication HTU1756-UM020UTH

Provides detailed information on installing, configuring and operating a GuardLogix controller

GuardLogix Controller Systems Safety Reference Manual, publication HTU1756-RM093UTH

Provides information on the safety concept and safety requirements for using GuardLogix controllers in safety applications

HTUwww.rosscontrols.comUTH

Ross Controls website containing more information on DM2 pneumatic safety valves.

Safety Accelerator Toolkit for GuardLogix Systems Quick Start, publication HTUIASIMP-QS005UTH

Provides step-by-step directions for using the diagrams and sample code included in the Safety Accelerator Toolkit

You can view or download publications at

HTUhttp://literature.rockwellautomation.comUTH. To order paper copies of

technical documentation, contact your local Rockwell Automation

distributor or sales representative.

Publication SAFETY-AT024A-EN-P – May 2009

Rockwell Automation, Allen-Bradley, GuardLogix, CompactBlock Guard I/O, RSLogix 5000 are trademarks of Rockwell Automation, Inc.

Trademarks not belonging to Rockwell Automation are property of their respective companies.

Publication SAFETY-AT024A-EN-P – May 2009 Copyright © 2009 Rockwell Automation, Inc. All rights reserved. Printed in U.SA