IODD
The IODD (IO Device Description) describes sensors and actuators. It contains information on identification, device parameters, process and diagnostic data, communication properties and the structure of the user interface in engineering tools. It consists of several files: a main file and optional external language files (both in XML format ), and optional image files (in PNG format ).
structure
The description structure of the IODD corresponds to ISO 15745 (Industrial automation systems and integration - Open systems application integration frameworks), with both the device profile and the communication network profile being combined in one file as a special feature.
In accordance with the structure defined in ISO 15745, the basic objects DeviceIdentity and DeviceFunction are provided in IODD for the device description. The DeviceIdentity object contains identification texts for display to the user and identification numbers for the automatic detection of sensors and actuators (IDs) in the system. Several variants can be described, which do not differ in terms of parameters, process and diagnostic data and communication, but in their order number. This ensures that the great variety of mechanical characteristics that characterize sensors and actuators does not lead to a high number of device descriptions and a high consumption of identification numbers. The DeviceFunction object is the carrier of all further information, provided it does not belong to the communication profile. It contains the description of the parameters, the process data, the diagnostics and the structure of the user interface.
The embedded Communication Network Profile is easily exchangeable; this means that IODD can easily be expanded to describe sensors and actuators with a communication interface other than IO-Link .
Language support
All texts can be given in multiple languages. For this purpose, only text marks are entered in the actual device description. Separate text lists (one for each supported language) assign the bookmarks to the language-dependent texts. Usually all text lists are placed in the main file. In the event of a subsequent translation into additional languages, text lists can also be supplied in separate files so that the main file can remain unchanged.
Standard definitions
All parameters and diagnoses predefined by the IO-Link standard are described in a file "IODD-StandardDefinitions [Version] .xml" with the same syntax as the IODD. These standard parameters and diagnoses are not described in the IODD itself, but only referenced from there.
IODD checker
The "IODD Checker" tool not only checks the schema conformity, but also all rules of the IODD specification that cannot be checked using an XML schema. After passing the test, the checker stamps the IODD. This test is mandatory. Engineering tools only accept stamped IODDs and thus save the implementation of the tests.
IODDfinder
As a central database for IO device descriptions, the IO-Link consortium operates an IODDfinder portal to meet the request of users of IO-Link technology to have a central access point to IODDs of all marketable IO-Link devices. It also enables direct connection of engineering and parameterization tools. Corresponding software tools receive access to this manufacturer-independent data pool via the Internet, which guarantees the user automatic access to all the description files required for operation on his IO-Link devices.
Specification and guideline
The IODD specification, an IODD guideline with examples and the IODD Checker were created by the IO-Link consortium. The current version is V1.0.1, which is used to describe devices according to IO-Link specification V1.0 and devices according to IO-Link specification V1.1 in the V1.0 compatibility mode. The future IODD V1.1 is used to describe devices according to IO-Link specification V1.1 and therefore does not replace V1.0.1.