s Preface Contents Organization Blocks 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 SIMATIC System

s

Preface

Contents

Organization Blocks 1

Common Parameters for SFCs 2

Copy and Block Functions 3

SFCs for Controlling Program

Execution 4

SFCs for Handling the System

Clock 5

SFCs for Handling Run-Time

Meters 6

SFCs/SFBs for Transferring

Data Records 7

DPV1 SFBs According to

PNO AK 1131 8

SFCs for Handling Time-of-Day

Interrupts 9

SFCs for Handling Time-Delay

Interrupts 10

SFCs for Handling

Synchronous Errors 11

SFCs for Handling Interrupts

and Asynchronous Errors 12

SFCs for Diagnostics 13

SFCs and SFBs for Updating

the Process Image and

Processing Bit Fields

14

System Functions for

Addressing Modules 15

SFCs for Distributed I/Os or

PROFINET IO 16

PROFInet 17

SIMATIC

System Software for

S7-300/400 System and

Standard Functions

Volume 1/2

Reference Manual

This manual is part of the documentation

package with the order number:

6ES7810-4CA08-8BW1 FBs for Cyclical Access to User

Data according to the PNO 18

Edition 03/2006

A5E00709327-01

Siemens AG

Automation and Drives

Postfach 4848

90437 NÜRNBERG

GERMANY

A5E00709327-01

03/2006

Copyright © Siemens AG 2006

Technical data subject to change

Safety Guidelines

This manual contains notices you have to observe in order to ensure your personal safety, as well as to

prevent damage to property. The notices referring to your personal safety are highlighted in the manual

by a safety alert symbol, notices referring to property damage only have no safety alert symbol. The

notices shown below are graded according to the degree of danger.

! Danger

indicates that death or severe personal injury will result if proper precautions are not taken.

! Warning

indicates that death or severe personal injury may result if proper precautions are not taken.

! Caution

with a safety alert symbol indicates that minor personal injury can result if proper precautions are not

taken.

Caution

without a safety alert symbol indicates that property damage can result if proper precautions are not

taken.

Notice

indicates that an unintended result or situation can occur if the corresponding notice is not taken into

account.

If more than one degree of danger is present, the warning notice representing the highest degree of

danger will be used. A notice warning of injury to persons with a safety alert symbol may also include a

warning relating to property damage.

Qualified Personnel

The device/system may only be set up and used in conjunction with this documentation. Commissioning

and operation of a device/system may only be performed by qualified personnel. Within the context of

the safety notices in this documentation qualified persons are defined as persons who are authorized to

commission, ground and label devices, systems and circuits in accordance with established safety

practices and standards.

Prescribed Usage

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.

Correct, reliable operation of the product requires proper transport, storage, positioning and assembly

as well as careful operation and maintenance.

Trademarks

All names identified by ® are registered trademarks of the Siemens AG.

The remaining trademarks in this publication may be trademarks whose use by third parties for their

own purposes could violate the rights of the owner.

Disclaimer of Liability

We have reviewed the contents of this publication to ensure consistency with the hardware and software

described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However,

the information in this publication is reviewed regularly and any necessary corrections are included in

subsequent editions.

System Software for S7-300/400 System and Standard Functions - Volume 1/2

A5E00709327-01 iii

Preface

Purpose

This manual provides you with a comprehensive overview of the organization

blocks (OB), system functions (SFC), system and standard function blocks (SFC),

and IEC functions contained in the operating systems of the CPUs of the S7-300

and S7-400, diagnostic data, system status lists (SZL), and events.

Note

Refer to the reference section of the "S7-300 Automation System

CPU Specifications: CPU 31xC and CPU 31x" and "S7-300 Automation System

CPU Specifications: CPU 312IFM - 318-2 DP“ /70/ or the

"Automation System S7-400: CPU Specifications" reference manual /101/ or the

Instruction List: S7-400 Programmable Controller /102/ (whichever version applies

to your CPU) for details of which of these functions and blocks are available on

which CPU. The properties of the CFBs and the S7 signaling functions for specific

CPUs are described in /70/ and /101/.

For information about the CPU operating systems, program design, and the

communications and diagnostic capabilities of the CPUs, refer to the

"Configuring Hardware and Communication Connections STEP 7 V5.4" manual

/234/ How to call functions and function blocks in your program is explained in the

language descriptions.

You program and assign parameters for all these functions using the STEP 7

standard software. How to use this software is described in the

"Programming with STEP 7 V5.4" manual /231/ and in the STEP 7 online help.

Audience

This manual is intended for programmers and engineers who are familiar with

controlling processes and are responsible for writing programs for programmable

logic controllers.

Preface

System Software for S7-300/400 System and Standard Functions - Volume 1/2

iv A5E00709327-01

STEP 7 Documentation Packages

The following table displays an overview of the STEP 7 documentation:

Documentation Purpose Order Number

STEP 7 Basic Information with

• Working with STEP 7 ,

Getting Started Manual

• Programming with STEP 7

• Configuring Hardware and

Communication Connections, STEP 7

• From S5 to S7, Converter Manual

Basic information for technical

personnel describing the methods

of implementing control tasks with

STEP 7 and the S7-300/400

programmable controllers.

6ES7810-4CA08-8BW0

STEP 7 Reference with

• Ladder Logic (LAD)/Function Block

Diagram (FBD)/Statement List (STL)

for S7-300/400 manuals

• Standard and System Functions for

S7-300/400

Volume 1 and Volume 2

Provides reference information

and describes the programming

languages LAD, FBD, and STL,

and standard and system

functions extending the scope of

the STEP 7 basic information.

6ES7810-4CA08-8BW1

Online Helps Purpose Order Number

Help on STEP 7 Basic information on

programming and configuring

hardware with STEP 7 in the form

of an online help.

Part of the STEP 7

Standard software.

Reference helps on STL/LAD/FBD

Reference help on SFBs/SFCs

Reference help on Organization Blocks

Context-sensitive reference

information.

Part of the STEP 7

Standard software.

Preface

System Software for S7-300/400 System and Standard Functions - Volume 1/2

A5E00709327-01 v

Online Help

The manual Volume 1 and Volume 2 is complemented by an online help which is

integrated in the software. This online help is intended to provide you with detailed

support when using the software.

The help system is integrated in the software via a number of interfaces:

• There are several menu commands which you can select in the Help menu:

The Contents command opens the index for the Help on STEP 7.

• Using Help provides detailed instructions on using the online help.

• The context-sensitive help offers information on the current context, for

example, an open dialog box or an active window. You can open the context￾sensitive help by clicking the "Help" button or by pressing F1.

• The status bar offers another form of context-sensitive help. It displays a short

explanation for each menu command when the mouse pointer is positioned on

the menu command.

• A brief explanation is also displayed for each icon in the toolbar when the

mouse pointer is positioned on the icon for a short time.

If you prefer to read the information from the online help in printed format, you can

print out individual help topics, books, or the entire online help.

This manual is an extract from the HTML-based Help on STEP 7. As the manual

and the online help share an almost identical structure, it is easy to switch between

the manual and the online help.

Feedback on Documentation

To help us to provide the best possible documentation for you and future STEP 7

users, we need your support. If you have any comments or suggestions relating to

this manual or the online help, please complete the questionnaire at the end of the

manual and send it to the address shown. Please include your own personal rating

of the documentation.

Other Manuals

The various S7-300 and S7-400 CPUs and the S7-300 and S7-400 modules are

described in the following manuals:

• For the S7-300 programmable logic controller, refer to the manuals: "

Automatisierungssystem S7-300 CPU-Daten: CPU 31xC und CPU 31x und

Automatisierungssystem S7-300 CPU-Daten: CPU 312 IFM bis 318-2 DP“ "

/70/, "S7-300, M7-300 Programmable Controllers Module Specifications" /71/

and in the Instruction List /72/.

• For the S7-400 programmable logic controller, refer to the manual:

"Automatisierungssystem S7-400: CPU Daten " /101/ and in the Instruction List

/102/.

Preface

System Software for S7-300/400 System and Standard Functions - Volume 1/2

vi A5E00709327-01

How to Use this Manual

This manual covers the following topics:

• Chapter 1 explains the functions of all the organization blocks.

• Chapter 2 describes the common parameters RET_VAL, REQ and BUSY.

• Chapters 3 to 29 describe the SFCs, SFBs and IEC-FCs.

• The Chapters sections 30 to 35 contain a description of the structure of the

diagnostic data, an overview of the SZL-IDs, the possible events, lists of the

SFCs, SFBs and FCs described in this manual, an overview of the SDBs.

• The bibliography contains a list of further manuals.

• The Glossary explains important terminology.

• The Index helps you to locate sections of text and topics quickly.

Conventions

References to other manuals and documentation are indicated by numbers in

slashes /.../. These numbers refer to the titles of manuals listed in the bibliography.

Special Note

The system functions can be interrupted. If there are any restrictions that apply to

certain SFCs or situations, these are explained in the description of the particular

SFC.

Further Support

If you have any technical questions, please get in touch with your Siemens

representative or responsible agent.

You will find your contact person at:

http://www.siemens.com/automation/partner

You will find a guide to the technical documentation offered for the individual

SIMATIC Products and Systems here at:

http://www.siemens.com/simatic-tech-doku-portal

The online catalog and order system is found under:

http://mall.automation.siemens.com/

Training Centers

Siemens offers a number of training courses to familiarize you with the SIMATIC

S7 automation system. Please contact your regional training center or our central

training center in D 90327 Nuremberg, Germany for details:

Telephone: +49 (911) 895-3200.

Internet: http://www.sitrain.com

Preface

System Software for S7-300/400 System and Standard Functions - Volume 1/2

A5E00709327-01 vii

Technical Support

You can reach the Technical Support for all A&D products

• Via the Web formula for the Support Request

http://www.siemens.com/automation/support-request

• Phone: + 49 180 5050 222

• Fax: + 49 180 5050 223

Additional information about our Technical Support can be found on the Internet

pages http://www.siemens.com/automation/service

Service & Support on the Internet

In addition to our documentation, we offer our Know-how online on the internet at:

http://www.siemens.com/automation/service&support

where you will find the following:

• The newsletter, which constantly provides you with up-to-date information on

your products.

• The right documents via our Search function in Service & Support.

• A forum, where users and experts from all over the world exchange their

experiences.

• Your local representative for Automation & Drives.

• Information on field service, repairs, spare parts and more under "Services".

Preface

System Software for S7-300/400 System and Standard Functions - Volume 1/2

viii A5E00709327-01

System Software for S7-300/400 System and Standard Functions - Volume 1/2

A5E00709327-01 ix

Contents

1 Organization Blocks 1-3

1.1 Overview of the Organization Blocks (OBs) ..................................................... 1-3

1.2 Program Cycle Organization Block (OB1)........................................................ 1-3

1.3 Time-of-Day Interrupt Organization Blocks (OB10 to OB17) ........................... 1-3

1.4 Time-Delay Interrupt Organization Blocks (OB20 to OB23)............................. 1-3

1.5 Cyclic Interrupt Organization Blocks (OB30 to OB38)...................................... 1-3

1.6 Hardware Interrupt Organization Blocks (OB40 to OB47)................................ 1-3

1.7 Status Interrupt OB (OB 55) ............................................................................. 1-3

1.8 Update Interrupt OB (OB 56)............................................................................ 1-3

1.9 Manufacturer Specific Interrupt OB (OB57)...................................................... 1-3

1.10 Multicomputing Interrupt Organization Block (OB60) ....................................... 1-3

1.11 Synchronous Cycle Interrupt OBs (OB 61 to OB 64) ....................................... 1-3

1.12 Technology Synchronization Interrupt OB (OB 65) .......................................... 1-3

1.13 I/O Redundancy Error OB (OB70).................................................................... 1-3

1.14 CPU Redundancy Error OB (OB72)................................................................. 1-3

1.15 Communication Redundancy Error OB (OB73) ............................................... 1-3

1.16 Time Error Organization Block (OB80)............................................................. 1-3

1.17 Power Supply Error Organization Block (OB81) .............................................. 1-3

1.18 Diagnostic Interrupt Organization Block (OB82) .............................................. 1-3

1.19 Insert / Remove Module Interrupt Organization Block (OB83)......................... 1-3

1.20 CPU Hardware Fault Organization Block (OB84) ............................................ 1-3

1.21 Priority Class Error Organization Block (OB85) ............................................... 1-3

1.22 Rack Failure Organization Block (OB86).......................................................... 1-3

1.23 Communication Error Organization Block (OB87)............................................ 1-3

1.24 Processing Interrupt OB (OB 88)...................................................................... 1-3

1.25 Background Organization Block (OB90)........................................................... 1-3

1.26 Startup Organization Blocks (OB100, OB101 and OB102).............................. 1-3

1.27 Programming Error Organization Block (OB121) ............................................. 1-3

1.28 I/O Access Error Organization Block (OB122) ................................................. 1-3

2 Common Parameters for SFCs 2-3

2.1 Evaluating Errors with Output Parameter RET_VAL........................................ 2-3

2.2 Meaning of the Parameters REQ, RET_VAL and BUSY with Asynchronous

SFCs................................................................................................................. 2-3

3 Copy and Block Functions 3-3

3.1 Copying Memory Area with SFC 20 "BLKMOV"............................................... 3-3

3.2 Uninterruptible Copying of Variables with SFC 81 "UBLKMOV"...................... 3-3

3.3 Initializing a Memory Area with SFC 21 "FILL"................................................. 3-3

3.4 Creating a Data Block with SFC 22 "CREAT_DB" ........................................... 3-3

3.5 Deleting a Data Block with SFC 23 "DEL_DB"................................................. 3-3

Contents

System Software for S7-300/400 System and Standard Functions - Volume 1/2

x A5E00709327-01

3.6 Testing a Data Block with SFC 24 "TEST_DB"................................................ 3-3

3.7 Compressing the User Memory with SFC 25 "COMPRESS"........................... 3-3

3.8 Transferring a Substitute Value to Accumulator 1 with SFC 44 "REPL_VAL" . 3-3

3.9 Generating Data Blocks in Load Memory with SFC 82 "CREA_DBL" ............. 3-3

3.10 Reading from a Data Block In Load Memory with SFC 83 "READ_DBL" ........ 3-3

3.11 Writing a Data Block in Load Memory with SFC 84 "WRIT_DBL".................... 3-3

3.12 Creating a Data Block with SFC 85 "CREA_DB" ............................................. 3-3

4 SFCs for Controlling Program Execution 4-3

4.1 Re-triggering Cycle Time Monitoring with SFC 43 "RE_TRIGR" ..................... 4-3

4.2 Changing the CPU to STOP with SFC 46 "STP".............................................. 4-3

4.3 Delaying Execution of the User Program with SFC 47 "WAIT"........................ 4-3

4.4 Triggering a Multicomputing Interrupt with SFC 35 "MP_ALM"........................ 4-3

4.5 Controlling CiR with SFC 104 "CiR" ................................................................. 4-3

5 SFCs for Handling the System Clock 5-3

5.1 Setting the TOD with SFC 0 "SET_CLK".......................................................... 5-3

5.2 Reading the Time with SFC 1 "READ_CLK".................................................... 5-3

5.3 Synchronizing Slave Clocks with SFC 48 "SNC_RTCB" ................................. 5-3

5.4 Setting the Time-of-Day and the TOD Status with SFC 100 "SET_CLKS"...... 5-3

6 SFCs for Handling Run-Time Meters 6-3

6.1 Runtime Meters ................................................................................................ 6-3

6.2 Handling Runtime meters with SFC 101 "RTM"............................................... 6-3

6.3 Setting the Runtime Meter with SFC 2 "SET_RTM"......................................... 6-3

6.4 Starting and Stopping a Run-time Meter with SFC 3 "CTRL_RTM"................. 6-3

6.5 Reading a Runtime Meter with SFC 4 "READ_RTM" ...................................... 6-3

6.6 Reading the System Time with SFC 64 "TIME_TCK" ...................................... 6-3

7 SFCs/SFBs for Transferring Data Records 7-3

7.1 Writing and Reading Data Records.................................................................. 7-3

7.2 Reading Defined Parameters with SFC 54 "RD_DPARM"............................... 7-3

7.3 Reading Predefined Parameters with SFC 102 "RD_DPARA" ........................ 7-3

7.4 Writing Dynamic Parameters with SFC 55 "WR_PARM" ................................. 7-3

7.5 Writing Default Parameters with SFC 56 "WR_DPARM" ................................. 7-3

7.6 Assigning Parameters to a Module with SFC 57 "PARM_MOD" ..................... 7-3

7.7 Writing a Data Record with SFC 58 "WR_REC" .............................................. 7-3

7.8 Reading a Data Record with SFC 59 "RD_REC"............................................. 7-3

7.9 Further Error Information for SFCs 55 to 59..................................................... 7-3

7.10 Reading Predefined Parameters with SFB 81 "RD_DPAR"............................. 7-3

8 DPV1 SFBs According to PNO AK 1131 8-3

8.1 Reading a Data Record with SFB 52 "RDREC"............................................... 8-3

8.2 Writing a Data Record with SFB 53 "WRREC"................................................. 8-3

8.3 Receiving an Interrupt with SFB 54 "RALRM".................................................. 8-3

8.4 Sending an Interrupt to the DP Master with SFB 75 "SALRM" ........................ 8-3

9 SFCs for Handling Time-of-Day Interrupts 9-3

9.1 Handling Time-of-Day Interrupts ...................................................................... 9-3

9.2 Characteristics of SFCs 28 to 31...................................................................... 9-3

9.3 Setting a Time-of-Day Interrupt with SFC 28 "SET_TINT"............................... 9-3

9.4 Canceling a Time-of-Day Interrupt with SFC 29 "CAN_TINT" ......................... 9-3

9.5 Activating a Time-of-Day Interrupt with SFC 30 "ACT_TINT" .......................... 9-3

9.6 Querying a Time-of-Day Interrupt with SFC 31 "QRY_TINT"........................... 9-3

Contents

System Software for S7-300/400 System and Standard Functions

A5E00709327-01 xi

10 SFCs for Handling Time-Delay Interrupts 10-3

10.1 Handling Time-Delay Interrupts...................................................................... 10-3

10.2 Starting a Time-Delay Interrupt with SFC 32 "SRT_DINT" ............................ 10-3

10.3 Querying a Time-Delay Interrupt with SFC 34 "QRY_DINT".......................... 10-3

10.4 Canceling a Time-Delay Interrupt with SFC 33 "CAN_DINT" ........................ 10-3

11 SFCs for Handling Synchronous Errors 11-3

11.1 Masking Synchronous Errors ......................................................................... 11-3

11.2 Masking Synchronous Errors with SFC 36 "MSK_FLT"................................. 11-3

11.3 Unmasking Synchronous Errors with SFC 37 "DMSK_FLT".......................... 11-3

11.4 Reading the Error Register with SFC 38 "READ_ERR"................................. 11-3

12 SFCs for Handling Interrupts and Asynchronous Errors 12-3

12.1 Delaying and Disabling Interrupt and Asynchronous Errors........................... 12-3

12.2 Disabling the Processing of New Interrupts and Asynchronous Errors

with SFC 39 "DIS_IRT"................................................................................... 12-3

12.3 Enabling the Processing of New Interrupts and Asynchronous Errors

with SFC 40 "EN_IRT".................................................................................... 12-3

12.4 Delaying the Processing of Higher Priority Interrupts and

Asynchronous Errors with SFC 41 "DIS_AIRT".............................................. 12-3

12.5 Enabling the Processing of Higher Priority Interrupts and

Asynchronous Errors with SFC 42 "EN_AIRT"............................................... 12-3

13 SFCs for Diagnostics 13-3

13.1 System Diagnostics ........................................................................................ 13-3

13.2 Reading OB Start Information with SFC 6 "RD_SINFO"................................ 13-3

13.3 Reading a System Status List or Partial List with SFC 51 "RDSYSST"......... 13-3

13.4 Writing a User-Defined Diagnostic Event to the Diagnostic Buffer with

SFC 52 "WR_USMSG"................................................................................... 13-3

13.5 Determining the OB Program Runtime with SFC 78 "OB_RT" ...................... 13-3

13.6 Diagnosis of the Current Connection Status with SFC 87 "C_DIAG" ............ 13-3

13.7 Identifying the Bus Topology of a DP Master System with SFC 103

"DP_TOPOL" .................................................................................................. 13-3

14 SFCs and SFBs for Updating the Process Image and Processing Bit Fields 14-3

14.1 Updating the Process Image Input Table with SFC 26 "UPDAT_PI" ............. 14-3

14.2 Updating the Process Image Output Table with SFC 27 "UPDAT_PO" ........ 14-3

14.3 Updating the Process Image Partition Input Table in a

Synchronous Cycle with SFC 126 "SYNC_PI"............................................... 14-3

14.4 Updating the Process Image Partition in a Synchronous Cycle

with SFC 127 "SYNC_PO" ............................................................................. 14-3

14.5 Setting a Bit Field in the I/O Area with SFC 79 "SET".................................... 14-3

14.6 Resetting a Bit Field in the I/O Area with SFC 80 "RSET" ............................. 14-3

14.7 Implementing a Sequencer with SFB 32 "DRUM".......................................... 14-3

15 System Functions for Addressing Modules 15-3

15.1 Querying the Logical Base Address of a Module with

SFC 5 "GADR_LGC" ...................................................................................... 15-3

15.2 Querying the Module Slot Belonging to a Logical Address with

SFC 49 "LGC_GADR" .................................................................................... 15-3

15.3 Querying all Logical Addresses of a Module with SFC 50 "RD_LGADR" ...... 15-3

15.4 Determining the Start Address of a Module with SFC 70 "GEO_LOG" ......... 15-3

15.5 Determining the Slot Belonging to a Logical Address with

SFC 71 "LOG_GEO" ...................................................................................... 15-3

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System Software for S7-300/400 System and Standard Functions - Volume 1/2

xii A5E00709327-01

16 SFCs for Distributed I/Os or PROFINET IO 16-3

16.1 Triggering a Hardware Interrupt on the DP Master with SFC 7 "DP_PRAL" . 16-3

16.2 Synchronizing Groups of DP Slaves with SFC 11 "DPSYC_FR"................... 16-3

16.3 Deactivating and Activating DP Slaves/PROFINET IO Devices

with SFC 12 "D_ACT_DP".............................................................................. 16-3

16.4 Reading Diagnostic Data of a DP Slave with SFC 13 "DPNRM_DG"

(Slave Diagnostics)......................................................................................... 16-3

16.5 Reading Consistent Data of a DP Standard Slave//PROFINET IO Device

with SFC 14 "DPRD_DAT"............................................................................. 16-3

16.6 Writing Consistent Data to a DP Standard Slave/PROFINET IO Device

with SFC 15 "DPWR_DAT" ............................................................................ 16-3

17 PROFInet 17-3

17.1 Background Information on SFCs 112, 113 and 114 ..................................... 17-3

17.2 Updating the Inputs of the User Program Interface for the

PROFInet Component with SFC 112 "PN_IN" ............................................... 17-3

17.3 Updating the Outputs of the PROFInet Interface for the

PROFInet Component with SFC 113 "PN_OUT" ........................................... 17-3

17.4 Updating DP Interconnections with SFC 114 "PN_DP" ................................. 17-3

18 FBs for Cyclical Access to User Data according to the PNO 18-3

18.1 Introduction to the FBs for Cyclical Access to User Data according

to the PNO ...................................................................................................... 18-3

18.2 Read All Inputs of a DP Standard Slave/PROFINET IO Device with

FB 20 "GETIO" ............................................................................................... 18-3

18.3 Write All Outputs of a DP Standard Slave/PROFINET IO Device with

FB 21 "SETIO"................................................................................................ 18-3

18.4 Read a Part of the Inputs of a DP Standard Slave/PROFINET IO Device

with FB 22 "GETIO_PART" ............................................................................ 18-3

18.5 Write a Part of the Outputs of a DP Standard Slave/PROFINET IO Device

with FB 23 "SETIO_PART"............................................................................. 18-3

System Software for S7-300/400 System and Standard Functions - Volume 1/2

A5E00709327-01 1-1

1 Organization Blocks

1.1 Overview of the Organization Blocks (OBs)

What Are Organization Blocks?

Organization Blocks (OBs) are the interface between the operating system of the

CPU and the user program. OBs are used to execute specific program sections:

• At the startup of the CPU

• In a cyclic or clocked execution

• Whenever errors occur

• Whenever hardware interrupts occur.

Organization blocks are executed according to the priority they are allocated.

Which OBs Are Available?

Not all CPUs can process all of the OBs available in STEP 7. Refer to Operations

lists /72/ and /102/ to determine which OBs are included with your CPU.

Organization Blocks

System Software for S7-300/400 System and Standard Functions - Volume 1/2

1-2 A5E00709327-01

Where to Find More Information?

Refer to the online help and the following manuals for more information:

• /70/: this manual contains the technical data that describe the capabilities of the

different S7-300 CPUs.

• /101/: this manual contains the technical data that describe the capabilities of

the different S7-400 CPUs.

The following table contains the start event belonging to each OB as well as the

default priority class.

OB Start Event Default Priority

Class

Explanation

OB1 End of startup or end of OB1 1 Free cycle

OB10

OB11

OB12

OB13

OB14

OB15

OB16

OB17

Time-of-day interrupt 0

Time-of-day interrupt 1

Time-of-day interrupt 2

Time-of-day interrupt 3

Time-of-day interrupt 4

Time-of-day interrupt 5

Time-of-day interrupt 6

Time-of-day interrupt 7

2

2

2

2

2

2

2

2

No default time

specified

OB20

OB21

OB22

OB23

Time-delay interrupt 0

Time-delay interrupt 1

Time-delay interrupt 2

Time-delay interrupt 3

3

4

5

6

No default time

specified

OB30

OB31

OB32

OB33

OB34

OB35

OB36

OB37

OB38

Cyclic interrupt 0 (default interval: 5 s)

Cyclic interrupt 1 (default interval: 2 s)

Cyclic interrupt 2 (default interval: 1 s)

Cyclic interrupt 3 (default interval: 500 ms)

Cyclic interrupt 4 (default interval: 200 ms)

Cyclic interrupt 5 (default interval: 100 ms)

Cyclic interrupt 6 (default interval: 50 ms)

Cyclic interrupt 7 (default interval: 20 ms)

Cyclic interrupt 8 (default interval: 10 ms)

7

8

9

10

11

12

13

14

15

Cyclic interrupts

OB40

OB41

OB42

OB43

OB44

OB45

OB46

OB47

Hardware interrupt 0

Hardware interrupt 1

Hardware interrupt 2

Hardware interrupt 3

Hardware interrupt 4

Hardware interrupt 5

Hardware interrupt 6

Hardware interrupt 7

16

17

18

19

20

21

22

23

Hardware interrupts

OB55 Status interrupt 2 DPV1 interrupts

OB56 Update interrupt 2

OB57 Manufacturer specific interrupt 2

OB60 SFC35 "MP_ALM" call 25 Multicomputing

interrupt

Organization Blocks

System Software for S7-300/400 System and Standard Functions - Volume 1/2

A5E00709327-01 1-3

OB Start Event Default Priority

Class

Explanation

OB 61

OB 62

OB 63

OB 64

Synchronous Cycle Interrupt 1

Synchronous Cycle Interrupt 2

Synchronous Cycle Interrupt 3

Synchronous Cycle Interrupt 4

25

25

25

25

Synchronous Cycle

Interrupt

OB 65 Technology synchronization interrupt 25 Technology

synchronization

interrupt

OB70

OB72

OB 73

I/O redundancy error (only in H CPUs)

CPU redundancy error (only in H CPUs)

Communication redundancy error OB (only in

H CPUs)

25

28

25

Redundancy error

interrupts

OB80 Time error 26, 28 1) Asynchronous error

interrupts

OB81 Power supply fault 26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB82 Diagnostic interrupt 26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB83 Insert/remove module interrupt 26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB84 CPU hardware fault 26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB85 Program error 26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB86 Failure of an expansion rack, DP master

system or station for distributed I/Os

26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB87 Communication error 26, 28 1) with S7-300,

25, 28 1) with S7-400

and CPU 318

OB 88 Processing interrupt 28

OB90 Warm or cold restart or delete a block being

executed in OB90 or load an OB90 on the

CPU or terminate OB90

29 2) Background cycle

OB100

OB101

OB102

Warm restart

Hot restart

Cold restart

27 1)

27 1)

27 1)

Startup

OB121

OB122

Programming error

I/O access error

Priority of the OB

causing the error

Priority of the OB

causing the error

Synchronous error

interrupts

1) Priority classes 27 and 28 are valid in the priority class model of the startup. 2) Priority class 29 corresponds to priority 0.29. This means that the background cycle has lower

priority than the free cycle.