IO-Link Interface
and
System
Specification
Version 1.1.3
June 2019
Order No: 10.002
IO-Link Interface and System Specification Version 1.1.3
_____________________________________________________________________________________________________________________
_____________________________________________________________________________________________________________________
©
Copyright IO-Link Community 2019 - All Rights Reserved Page 2 of 294
File name: IOL-Interface-Spec_10002_V113_Jun19
The IO-Link technology is standardized in IEC 61131-9. The IO-Link Community is a D-Liaison
member in the corresponding IEC working group. This document (V1.1.3) covers all Change
Requests within the IO-Link CR database up to ID 213 and will be the basis for a maintenance
cycle of IEC 61131-9.
Any comments, proposals, requests on this document are appreciated through the IO-Link CR
database www.io-link-projects.com. Please provide name and email address.
Login: IO-Link-V113
Password: Report
Important notes:
NOTE 1 The IO-Link Community Rules shall be observed prior to the development and marketing of IO-Link products.
The document can be downloaded from the www.io-link.com portal.
NOTE 2 Any IO-Link Device shall provide an associated IODD file. Easy access to the file and potential updates shall
be possible. It is the responsibility of the IO-Link Device manufacturer to test the IODD file with the help of
the IODD-Checker tool available per download from www.io-link.com.
NOTE 3 Any IO-Link devices shall provide an associated manufacturer declaration on the conformity of the device. A
corresponding form with references to relevant documents is available per download from www.io-link.com.
Disclaimer:
The attention of adopters is directed to the possibility that compliance with or adoption of IO-Link Community
specifications may require use of an invention covered by patent rights. The IO-Link Community shall not be
responsible for identifying patents for which a license may be required by any IO-Link Community specification, or
for conducting legal inquiries into the legal validity or scope of those patents that are brought to its attention. IO-
Link Community specifications are prospective and advisory only. Prospective users are responsible for protecting
themselves against liability for infringement of patents.
The information contained in this document is subject to change without notice. The material in this document details
an IO-Link Community specification in accordance with the license and notices set forth on this page. This
document does not represent a commitment to implement any portion of this specification in any company's
products.
WHILE THE INFORMATION IN THIS PUBLICATION IS BELIEVED TO BE ACCURATE, THE IO-LINK COMMUNITY
MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL
INCLUDING, BUT NOT LIMITED TO ANY WARRANTY OF TITLE OR OWNERSHIP, IMPLIED WARRANTY OF
MERCHANTABILITY OR WARRANTY OF FITNESS FOR PARTICULAR PURPOSE OR USE.
In no event shall the IO-Link Community be liable for errors contained herein or for indirect, incidental, special,
consequential, reliance or cover damages, including loss of profits, revenue, data or use, incurred by any user or
any third party. Compliance with this specification does not absolve manufacturers of IO-Link equipment, from the
requirements of safety and regulatory agencies (TÜV, IFA, UL, CSA, etc.).
® is registered trademark. The use is restricted for members of the IO-Link
Community. More detailed terms for the use can be found in the IO-Link Community Rules on
www.io-link.com.
Conventions: In this specification the following key words (in bold text) will be used:
may: indicates flexibility of choice with no implied preference.
should: indicates flexibility of choice with a strongly preferred implementation.
shall: indicates a mandatory requirement. Designers shall implement such mandatory require-
ments to ensure interoperability and to claim conformity with this specification.
highly recommended: indicates that a feature shall be implemented except for well-founded cases. Vendor shall
document the deviation within the user manual and within the manufacturer declaration.
Publisher:
IO-Link Community
c/o PROFIBUS Nutzerorganisation
Haid-und-Neu-Str. 7
76131 Karlsruhe
Germany
Phone: +49 721 / 96 58 590
Fax: +49 721 / 96 58 589
E-mail: info@io-link.com
Web site: www.io-link.com
© No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
IO-Link Interface and System © IO-Link – 3 – Version 1.1.3
CONTENTS
INTRODUCTION ................................................................................................................... 21
1 Scope ............................................................................................................................ 23
2 Normative references .................................................................................................... 23
3 Terms, definitions, symbols, abbreviated terms and conventions ................................... 24
3.1 Terms and definitions............................................................................................ 24
3.2 Symbols and abbreviated terms ............................................................................ 28
3.3 Conventions .......................................................................................................... 30
General ......................................................................................................... 30
Service parameters ....................................................................................... 30
Service procedures ........................................................................................ 30
Service attributes........................................................................................... 31
Figures .......................................................................................................... 31
Transmission octet order ............................................................................... 31
Behavioral descriptions.................................................................................. 31
4 Overview of SDCI (IO-Link
TM
) ........................................................................................ 33
4.1 Purpose of technology .......................................................................................... 33
4.2 Positioning within the automation hierarchy .......................................................... 33
4.3 Wiring, connectors and power ............................................................................... 34
4.4 Communication features of SDCI .......................................................................... 34
4.5 Role of a Master ................................................................................................... 36
4.6 SDCI configuration ................................................................................................ 37
4.7 Mapping to fieldbuses and/or other upper level systems ....................................... 37
4.8 Standard structure ................................................................................................ 37
5 Physical Layer (PL) ....................................................................................................... 38
5.1 General ................................................................................................................. 38
Basics ........................................................................................................... 38
Topology ....................................................................................................... 38
5.2 Physical layer services ......................................................................................... 39
Overview ....................................................................................................... 39
PL services .................................................................................................... 40
5.3 Transmitter/Receiver ............................................................................................. 41
Description method ........................................................................................ 41
Electrical requirements .................................................................................. 41
Timing requirements ...................................................................................... 46
5.4 Power supply ........................................................................................................ 49
Power supply options ..................................................................................... 49
Port Class B .................................................................................................. 50
Power-on requirements .................................................................................. 51
5.5 Medium ................................................................................................................. 51
Connectors .................................................................................................... 51
Cable ............................................................................................................. 52
6 Standard Input and Output (SIO) ................................................................................... 53
7 Data link layer (DL)........................................................................................................ 53
7.1 General ................................................................................................................. 53
7.2 Data link layer services ......................................................................................... 55
Version 1.1.3 – 4 – IO-Link Interface and System © IO-Link
DL-B services ................................................................................................ 55
DL-A services ................................................................................................ 64
7.3 Data link layer protocol ......................................................................................... 68
Overview ....................................................................................................... 68
DL-mode handler ........................................................................................... 69
Message handler ........................................................................................... 76
Process Data handler .................................................................................... 83
On-request Data handler ............................................................................... 86
ISDU handler ................................................................................................. 89
Command handler ......................................................................................... 93
Event handler ................................................................................................ 95
8 Application layer (AL) .................................................................................................... 98
8.1 General ................................................................................................................. 98
8.2 Application layer services ..................................................................................... 99
AL services within Master and Device ............................................................ 99
AL Services ................................................................................................... 99
8.3 Application layer protocol .................................................................................... 107
Overview ..................................................................................................... 107
On-request Data transfer ............................................................................. 107
Event processing ......................................................................................... 111
Process Data cycles .................................................................................... 115
9 System Management (SM) ........................................................................................... 116
9.1 General ............................................................................................................... 116
9.2 System Management of the Master ..................................................................... 116
Overview ..................................................................................................... 116
SM Master services ..................................................................................... 118
SM Master protocol...................................................................................... 123
9.3 System Management of the Device ..................................................................... 130
Overview ..................................................................................................... 130
SM Device services ..................................................................................... 132
SM Device protocol ..................................................................................... 137
10 Device ......................................................................................................................... 143
10.1 Overview ............................................................................................................ 143
10.2 Process Data Exchange (PDE) ........................................................................... 143
10.3 Parameter Manager (PM) .................................................................................... 144
General ....................................................................................................... 144
Parameter manager state machine .............................................................. 144
Dynamic parameter ..................................................................................... 146
Single parameter ......................................................................................... 146
Block Parameter .......................................................................................... 148
Concurrent parameterization access ............................................................ 150
Command handling ...................................................................................... 150
10.4 Data Storage (DS) .............................................................................................. 150
General ....................................................................................................... 150
Data Storage state machine ......................................................................... 151
DS configuration .......................................................................................... 153
DS memory space ....................................................................................... 153
DS Index_List .............................................................................................. 153
DS parameter availability ............................................................................. 153
IO-Link Interface and System © IO-Link – 5 – Version 1.1.3
DS without ISDU .......................................................................................... 154
DS parameter change indication .................................................................. 154
10.5 Event Dispatcher (ED) ........................................................................................ 154
10.6 Device features ................................................................................................... 154
General ....................................................................................................... 154
Device backward compatibility ..................................................................... 154
Protocol revision compatibility ..................................................................... 154
Visual SDCI indication ................................................................................. 155
Parameter access locking ............................................................................ 155
Data Storage locking ................................................................................... 155
Locking of local parameter entries ............................................................... 155
Locking of local user interface ..................................................................... 155
Offset time ................................................................................................... 155
Data Storage concept .................................................................................. 156
Block Parameter .......................................................................................... 156
10.7 Device reset options ........................................................................................... 156
Overview ..................................................................................................... 156
Device reset ................................................................................................ 157
Application reset .......................................................................................... 157
Restore factory settings ............................................................................... 157
Back-to-box ................................................................................................. 157
10.8 Device design rules and constraints .................................................................... 158
General ....................................................................................................... 158
Process Data ............................................................................................... 158
Communication loss .................................................................................... 158
Direct Parameter ......................................................................................... 158
ISDU communication channel ...................................................................... 158
DeviceID rules related to Device variants .................................................... 159
Protocol constants ....................................................................................... 159
10.9 IO Device description (IODD) .............................................................................. 159
10.10 Device diagnosis ................................................................................................. 160
Concepts ..................................................................................................... 160
Events ......................................................................................................... 161
Visual indicators .......................................................................................... 161
10.11 Device connectivity ............................................................................................. 162
11 Master ......................................................................................................................... 162
11.1 Overview ............................................................................................................ 162
Positioning of Master and Gateway Applications .......................................... 162
Structure, applications, and services of a Master ......................................... 163
Object view of a Master and its ports ........................................................... 164
11.2 Services of the Standardized Master Interface (SMI) ........................................... 164
Overview ..................................................................................................... 164
Structure of SMI service arguments ............................................................. 166
Concurrency and prioritization of SMI services ............................................ 167
SMI_MasterIdentification ............................................................................. 167
SMI_PortConfiguration ................................................................................ 168
SMI_ReadbackPortConfiguration ................................................................. 169
SMI_PortStatus ........................................................................................... 171
SMI_DSToParServ ...................................................................................... 172
