Siemens SIMATIC FM 351 User manual

Preface, Contents
User Information
Product Overview 1
Principles of Positioning 2
Installing and Removing
the FM 351 3
Wiring the FM 351 4
FM 351 Parameterization 5
Programming the FM 351 6
Setting up the FM 351 7
Reference Information
Machine Data and Increments 8
Operating Modes and Settings 9
Encoders 10
Error Handling 11
Structure of the Channel DB 12
Appendices
Technical Specifications A
Connecting Cables B
Glossary, Index
EWA 4NEB 720 6001-02
FM 351 Positioning Function
Module
Installation and Parameter
Assignment
Manual
SIMATIC
Edition 1

ii
FM 351 Positioning Function Module
EWA 4NEB 720 6001 02
This manual contains notices which you should observe to ensure your own personal safety, as
well as to protect the product and connected equipment. These notices are highlighted in the
manual by a warning triangle and are marked as follows according to the level of danger:
!Danger
indicates that death, severe personal injury or substantial property damage will result if proper
precautions are not taken.
!Warning
indicates that death, severe personal injury or substantial property damage can result if proper
precautions are not taken.
!Caution
indicatesthatminorpersonalinjuryorpropertydamagecanresultifproperprecautionsarenottaken.
Note
draws your attention toparticularly important informationon the product,handling the product,or
to a particular part of the documentation.
The device/system may only be set up and operated in conjunction with this manual. Only quali-
fied personnel should be allowed to install and work on this equipment. Qualified persons are
defined as persons who are authorized to commission, to ground, and to tag circuits, equipment,
and systems in accordance with established safety practices and standards.
Note the following:
!Warning
This device and its components may only be used for the applications described in the catalog or
the technical description, and only in connection with devices or components from other
manufacturers which have been approved or recommended by Siemens.
This product can only function correctly and safely if it is transported, stored, set up, and
installed correctly, and operated and maintained as recommended.
SIMATICand SINECare registered trademarks of SIEMENS AG.
Third parties using for their own purposes any other names in this document which refer to trade-
marks might infringe upon the rights of the trademark owners.
Wehavecheckedthecontentsofthismanualforagreementwiththe
hardwareandsoftwaredescribed. Since deviationscannot be pre-
cludedentirely,we cannot guarantee full agreement. However,the
data in this manual are reviewed regularly and any necessary cor-
rectionsincludedinsubsequenteditions.Suggestionsforimprove-
ment are welcomed.
  Copyright Siemens AG 1996 All rights reserved
The reproduction, transmission or use of this document or its
contents is not permitted without express written authority.
Offenders will be liable for damages. All rights, including rights
createdbypatentgrantorregistrationofautilitymodelordesign,are
reserved.
Siemens AG
Automation Group
Industrial Automation Systems
P.O. Box 4848, D-90327 Nuremberg Siemens AG 1996
Technical data subject to change.
Siemens Aktiengesellschaft Order No. EWA 4NES 720 6000-02
Safety Guidelines
Qualified Personnel
Correct Usage
Trademarks

iii
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Preface
This manual describes all the steps that are necessary to effectively use the
FM 351 Positioning Function Module.
This manual describes the hardware and software of the FM 351 Positioning
Function Module. The manual contains the following subjects:
Principles of positioning
Installing and removing the FM 351
Wiring the FM 351
Assigning the FM 351 parameters
Programming the FM 351
Setting up the FM 351
Reference information
Appendices
For queries about the use of products described in this manual, the answers to
which you cannot find here, please consult your Siemens contact person at
the appropriate representatives and offices. You will find addresses, for ex-
ample, in the appendix “SIEMENS Worldwide” to the manual S7-300 Pro-
grammable Controller, Hardware and Installation.
With queries or comments about the manual itself, please fill in the reply slip
located at the end of the manual and return it to the stated address. Please
also enter your personal assessment in the manual reply slip.
We offer courses designed to make your introduction to the SIMATIC S7 Pro-
grammable Controller easier. To obtain information about these, please con-
tact your regional training center or the central training center in D-90027
Nuremberg, Tel. [phone].
This manual contains the description of the FM 351 Positioning Function
Module which is valid at the time of publication. We reserve the right to de-
scribe changes to the functional features of the FM 351 in product informa-
tion.
Our products fulfill the requirements of the EU guideline 89/336/EWG
“Electromagnetic Compatibility” and of the harmonized European standards
(EN) listed in it.
Purpose
Audience
Additional
Assistance
Scope of this
Manual
CE Labeling

iv FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
The EU declarations of conformity are kept available for the responsible au-
thorities according to the above-mentioned EU guideline at:
Siemens Aktiengesellschaft
Automation Division
AUT E 148
P.O. Box 1963
D-92209 Amberg
Germany
In the appendix you will find a list of other references about the S7-300 and
programmable logic controllers.
The manual contains the following access aids to make it easier for you to
access special information:
At the beginning of the manual you will find a comprehensive contents
list together with lists of figures and tables contained in the complete
manual.
In the chapters you will find information giving you an overview of the
section’s contents in the left-hand column on each page.
Following the reference chapter, you will find a glossary in which the
important specialist terms used in the manual are defined.
At the end of the manual you will find a comprehensive index, enabling
you quick access to the required information.
Other References
How to Use This
Manual
Preface

v
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Contents
1 Product Overview
1.1 FM 351 Fields of Application 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Components in Open-Loop Positioning 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Principles of Positioning
2.1 Ranges and Switching Points in the Region of the Target Position 2-3. . . . . .
2.2 Positioning Velocity Curve 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Target Approach 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 End of Positioning 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Installing and Removing the FM 351
3.1 Installing the FM 351 Positioning Function Module 3-2. . . . . . . . . . . . . . . . . . .
3.2 Removing the FM 351 Positioning Function Module 3-3. . . . . . . . . . . . . . . . . .
4 Wiring the FM 351
4.1 Wiring the Power Controller 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Description of the Encoder Interface 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Connecting the Encoders 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 Description of the Peripheral Interface 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5 Wiring the Peripheral Interface 4-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 FM 351 Parameterization
6 Programming the FM 351
6.1 Principles of Programming an FM 351 6-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.1 Principle of Communication between CPU and FM 351 6-4. . . . . . . . . . . . . . .
6.1.2 Calling Functions 6-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.3 Interrupt Handling 6-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2 Functions which Control the FM 351 6-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.1 FC INC_MOD 6-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.2 FC JOG_MODE 6-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.3 FC REF_MODE 6-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3 Functions which Write Data to the FM 351 6-18. . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1 FC REFPT 6-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2 FC ACT_VAL 6-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.3 FC SNG_FCT 6-24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4 FC SNG_COM 6-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.5 FC TG254 6-26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.6 FC TG253_5 6-27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

vi FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
6.4 Functions which Read Data from the FM 351 6-28. . . . . . . . . . . . . . . . . . . . . . . .
6.4.1 FC DIAG_INF 6-30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.2 FC ACT_DAT 6-31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.5 Programming Example 6-32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.6 Technical Data 6-35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Setting Up the FM 351
8 Machine Data and Increments
8.1 Basic Data 8-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2 Machine Data for the Drive 8-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.3 Machine Data for the Axis 8-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4 Absolute Encoder Adjustment 8-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.5 Machine Data for the Encoder 8-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.6 Resolution 8-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.7 Incremental Dimensions 8-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9 Operating Modes and Settings
9.1 Generally Applicable Definitions 9-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2 Jogging Operating Mode 9-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.3 Seek-Reference-Point Operating Mode 9-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.4 Possibilities for the Seek-Reference-Point Mode 9-9. . . . . . . . . . . . . . . . . . . . .
9.5 Incremental Operating Mode 9-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.6 Setting Set Actual Value 9-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.7 Setting Set Reference Point 9-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.8 Single Setting Loop Traverse 9-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.9 Single Setting Do Not Evaluate Enable Input 9-19. . . . . . . . . . . . . . . . . . . . . . . . .
10 Encoders
10.1 Incremental Encoders 10-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.2 Selecting an Incremental Encoder 10-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.3 Absolute Encoders 10-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.4 Selecting an Absolute Encoder 10-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11 Error Handling
11.1 Module Defects 11-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.2 Diagnostic Interrupts 11-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.3 General Errors 11-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12 Structure of the Channel DB
Contents

vii
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
A Technical Specifications
A.1 General Technical Specifications A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2 Special Technical Specifications A-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B Connecting Cables
B.1 Connecting Cable for Incremental Encoder Siemens 6FX 2001-2
(Vp=5V; RS 422) B-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2 Connecting Cable for Incremental Encoder Siemens 6FX 2001-2
(Vp=24V; RS 422) B-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.3 Connecting Cable for Incremental Encoder Siemens 6FX 2001-4
(Vp=24V; HTL) B-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4 Connecting Cable for Absolute Encoder Siemens 6FX 2001-5
(Vp=24V; SSI) B-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents

viii FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Figures
1-1 View of the FM 351 Positioning Function Module 1-1. . . . . . . . . . . . . . . . . . . . .
1-2 FM 351 in the S7-300 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3 Example of a High-Bay Warehouse 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4 Electronic Cam Controller 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1 Controlled Positioning 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2 Ranges and Switching Points Around the Target 2-3. . . . . . . . . . . . . . . . . . . . .
2-3 Velocity Curve on Approaching a Target Position (Basic Shape) 2-4. . . . . . . .
2-4 Target Approach of Positioning 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-5 End of Positioning 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-6 Abort of Positioning; The Signal POS_RCD is Not Set 2-8. . . . . . . . . . . . . . . .
4-1 Wiring Diagram for an Open-Loop Positioning System 4-2. . . . . . . . . . . . . . . .
4-2 Installation in a Cabinet 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 Contactor Circuit 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4 Position of the Subminiature Cannon Sockets X2 and X3 4-6. . . . . . . . . . . . . .
4-5 Connection of an Encoder to the FM 351 Positioning Function Module 4-8. .
4-6 Position of the Front Connector 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-7 Wiring of the Front Connector 4-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-1 Principle of Communication between the CPU and FM 351 6-5. . . . . . . . . . . .
8-1 Limits for Entry of Incremental Dimensions 8-17. . . . . . . . . . . . . . . . . . . . . . . . . .
8-2 Symmetrical Position of the Switch-off and Switchover Points
for Increment 255 8-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-1 Starting the Jogging Operating Mode 9-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-2 Starting a Seek-Reference-Point Traverse 9-8. . . . . . . . . . . . . . . . . . . . . . . . . . .
9-3 Starting the Incremental Mode 9-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-4 Loop Traverse to a Target at the Software Limit Switch End 9-18. . . . . . . . . . . .
10-1 Signal Waveforms from Incremental Encoders 10-2. . . . . . . . . . . . . . . . . . . . . . .
10-2 Quadruple Evaluation 10-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11-1 Status and Error Indicators on the FM 351 11-2. . . . . . . . . . . . . . . . . . . . . . . . . .
11-2 Diagnostic Chart: Bits in the Channel DBs from Byte 72 Onwards
(DIAGNOSTIC_INT_INFO) 11-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12-1 Channel DB Structure 12-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents

ix
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Tables
4-1 Assignment of the 15-Pin Subminiature Cannon Sockets X2 and X3 4-6. . . .
4-2 Front connector assignment 4-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 Digital Input Functions 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4 Digital Output Functions 4-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-1 Entries in the Channel DB 6-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-2 Overview of All Available Function Blocks 6-4. . . . . . . . . . . . . . . . . . . . . . . . . . .
6-3 Evaluating the Diagnostic Information from the FM 351 6-9. . . . . . . . . . . . . . .
6-4 Brief Description of the Mode FCs 6-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-5 Start Commands for the Operating Modes 6-10. . . . . . . . . . . . . . . . . . . . . . . . . .
6-6 List of the FCs which Write Data to the FM 351 6-18. . . . . . . . . . . . . . . . . . . . . .
6-7 Requirements for Calling Writing Functions 6-18. . . . . . . . . . . . . . . . . . . . . . . . .
6-8 FCs which Read Data 6-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-9 Blocks in the Example Project 6-32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-10 Technical Data for the FM 351 Technological Functions 6-35. . . . . . . . . . . . . . .
6-11 Processing Times for the FM 351 Technological Functions 6-35. . . . . . . . . . . .
8-1 Basic Data 8-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-2 Drive Data 8-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-3 Machine Data for the Axis 8-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-4 Machine Data for the Encoder 8-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-1 Jogging with a Synchronized and Non-Synchronized Axis 9-5. . . . . . . . . . . .
9-2 Start Commands for a Seek-Reference-Point Traverse 9-7. . . . . . . . . . . . . . . .
9-3 Types of Seek-Reference-Point Mode 9-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-4 All Possibilities for a Seek-Reference-Point Mode 9-9. . . . . . . . . . . . . . . . . . . .
9-5 Start Commands for the Incremental Mode 9-12. . . . . . . . . . . . . . . . . . . . . . . . .
9-6 Displacement of the Working Range on the Axis by Set Actual Value 9-15. . .
9-7 Displacement of the Working Range on the Axis by Set reference point 9-16.
9-8 Calculation of the Position of the Fictitious Target during a Loop Traverse 9-17
9-9 Behavior of the Start Signals during the Operating Modes 9-19. . . . . . . . . . . .
11-1 Diagnostic Interrupts for Internal Errors 11-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12-1 Contents in the Channel DB 12-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents

xFM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Contents

1-1
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Product Overview
The FM 351 Positioning Function Module for rapid and creep speed drives is
used for controlled positioning. The module consists of two independent
channels and can therefore control rotary or linear axes. An incremental or
absolute encoder (SSI) can be connected to the module for each channel.
The module operates automatically. A user program in S7 controls the posi-
tioning module.
The FM 351 Positioning Function Module for rapid and creep speed drives is
equipped with powerful operating modes, settings and commands. The most
important of these are listed below:
Absolute and relative incremental modes
Search for reference
Set actual value, set reference point
Loop mode and many more.
The FM 351 Positioning Function Module for rapid and creep speed drives
does not need any maintenance and requires no batteries.
Bus connector
Rail
CPU
Figure 1-1 View of the FM 351 Positioning Function Module
FM 351
Functions
1

1
1-2 FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
The S7-300 Programmable Controller consists of a CPU and various signal
modules which are mounted on a rail.
You can operate a number of FM 351 Positioning Function Modules simulta-
neously. Combinations with other FM/CP modules are also possible. A typi-
cal application is the combination with an FM 352 Electronic Cam Control-
ler.
S7-300
CPU
PS IM SM SM FM 351
Rail
Parameter assignment
and set-up with
FM-Config
and programming with
function blocks.
PC/PG
SM SM
Figure 1-2 FM 351 in the S7-300
You will find the following subjects in this chapter:
Section Contents Page
1.1 FM 351 Fields of Application 1-3
1.2 Components in Open-Loop Positioning 1-4
FM 351 in the
S7-300
Chapter Overview
Product Overview

1
1-3
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
1.1 FM 351 Fields of Application
Below are a few examples from the field of controlled positioning which
show the variation of applications possible with the FM 351.
Various wooden parts are processed with a profile machine. Different work-
ing steps and routing heads are required to process the wood. The various
heads are changed by a controlled positioning process.
The molded parts in an injection molding machine are removed from the tool
by a gripper arm. The arm is controlled by the positioning module.
Standard containers are stored in a high-bay warehouse.
Rack operating device
A
B
C
Height
adjustment High-bay
warehouse
Goods in
table
13456789
Fork Traverse axis
Figure 1-3 Example of a High-Bay Warehouse
Fields of
Application
Control of Feed
Processes
Simple Handling
Processes
High-Bay
Warehouse
Product Overview

1
1-4 FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
1.2 Components in Open-Loop Positioning
In Figure 1-4 you can see the control circuit and components of an open-loop
positioning system.
Leistungs-
ansteue-
rung
Safety
device
Line voltage
Mechanical
transmission
elements
CPU
Parameterization interface
and function blocks
PC
EMER-
GENCY
STOP
Power
controller
Processing
stations
Limit switch
MEncoder
Motion
FM 351 Positioning
Function Module
Motor
Figure 1-4 Electronic Cam Controller
The power controller is controlled via digital outputs. It may, for example,
consist of a contactor circuit.
The power controller switches the motor off:
When operating faults occur (user presses EMERGENCY STOP switch)
When the limit switch is reached (safety device trips the power controller)
The motor is controlled by the power controller and drives the axis.
The FM 351 Positioning Function Module determines the present actual posi-
tion of the axis via an encoder. Here, pulses are measured which are propor-
tional to the distance moved.
On reaching certain axis positions the power controller is controlled appropri-
ately via the digital outputs.
Control Circuit
Power Controller
Motor
FM 351
Positioning
Function Module
Product Overview

1
1-5
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
The mechanical transmission elements include:
Toothed belts
Spindle
Toothed rack/pinion
Hydraulic cylinder
Gear unit
Coupling systems
The CPU executes the controlling user program (sequential program). Data
and signals are interchanged via function blocks.
The PC/PG (programming device) is used for
Parameterization: You parameterize the FM 351 with the parameteriza-
tion interface.
Testing and setting up with the parameterization interface.
Programming: You program the FM 351 with function blocks which you
can directly link into the user program.
Mechanical Trans-
mission Elements
(Axis)
CPU
PC/PG
(Programming
Device)
Product Overview

1
1-6 FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Product Overview

2-1
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Principles of Positioning
Encoders supply pulses or numerical values as output signals. The encoder
output signals describe the displacement of the load to be positioned. When
the displacement reaches a specified setpoint, then with controlled position-
ing the drive is switched over or switched off.
Power
controller
M
Target Load
MotorEncoder
FM 351
Positioning
Function
Module
Figure 2-1 Controlled Positioning
Each positioning process has the following features:
A target position to which the load is positioned.
A travel range.
Parameters determining the positioning sequence.
The target position is first approached at high speed (rapid speed). At a speci-
fied distance from the target position the speed is switched to a lower speed
(creep speed). Shortly before the axis reaches the target position, and also at
a specified distance from the target position, the drive is switched off. The
FM 351 executes the target approach and ensures reliable positioning. The
FM 351 is a positioning module for open-loop positioning.
What Does
’Controlled
Positioning’
Mean?
Open-Loop
Positioning
2

2
2-2 FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
If you carry out open-loop positioning with the FM 351, the drive is con-
trolled with rapid and creep speeds in the appropriate direction using digital
outputs.
With the FM 351 Positioning Function Module for rapid and creep speed
drives you can position two axes independently of one another. These axes
can be rotary or linear axes.
You will find the following subjects in this chapter:
Section Contents Page
2.1 Ranges and switching points in the region of the target posi-
tion 2-3
2.2 Positioning velocity curve 2-4
2.3 Target approach 2-5
2.4 End of positioning 2-7
Chapter Overview
Principles of Positioning

2
2-3
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
2.1 Ranges and Switching Points in the Region of the Target Position
This chapter gives information about the combined effects of individual ma-
chine data. You will find a description of the machine data in Chapter 8.
Each target position is characterized by a number of ranges which you para-
meterize by entering values. Each range carries out a different task:
Range Explanation
Switchover
difference A specified displacement, defining the distance to the target, at which the drive switches from rapid speed to creep speed.
Switch-off difference A specified displacement, defining the distance to the target, at which the drive is switched
off.
Standstill range A symmetrical range about the target position. This range becomes active when PEH is sig-
naled. If the range is left without a valid request, the FM 351 signals an error.
Target range A symmetrical range about the target position. The target is reached when the drive undercuts
the standstill velocity within this range.
The figure shows you how the switching points and ranges about the target
position are arranged.
Target
–1000 mm 1000 mm0
Switching point at the limit of the switchover difference, positive/negative
Switch-off point at the limit of the switch-off difference, positive/negative
1
23
4 5
6
Operating range
Target rangeStandstill range
1
2 3
4 5
6 7
7
Figure 2-2 Ranges and Switching Points Around the Target
Note the following rules for the ranges shown:
The half target range must be smaller than the switch-off difference (incl.
the limits).
The switch-off difference must lie within the relevant switchover differ-
ence.
The dynamic characteristics of the drive must be considered when input-
ting values so that a reliable approach to the target is possible.
Introduction
Definition of the
Switching Points
and Ranges
Position of the
Switching and
Monitoring Ranges
Rules for the
Ranges
Principles of Positioning

2
2-4 FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
2.2 Positioning Velocity Curve
This chapter gives an overview of the basic curve for positioning on a target.
The velocity and also the basic curve mainly depend on the possibilities pro-
vided by the power controller which you are using.
We show you the basic sequence on approaching a target position in Fig. 2-3
below.
For the sake of simplicity we have assumed that the velocity changes linearly
over the distance traveled.
The following basic curve for positioning is then produced:
Target
–1000 mm 1000 mm0
Switchover difference, positive
Switch-off difference, positive
123
4
Target range
Standstill range
1
2
3
4
vrapid
vcreep
Figure 2-3 Velocity Curve on Approaching a Target Position (Basic Shape)
Please refer to Chapter 2.3 for the target approach.
The effect of the FM 351 monitoring is shown. In addition, you can see when
the FM 351 signals reaching a position.
You can determine all the statuses during positioning from the response sig-
nals. Please read Chapter 12 for more information.
Introduction
Velocity Curve on
Approaching a
Target Position
Target Approach
Evaluation by
Program
Principles of Positioning