DE102019102568A1 - Data transmission method - Google Patents

Abstract

The present invention relates to a method for data transmission between an IO-Link device (1) and an IO-Link master (2), the data transmission being defined in the IO-Link standard, with at least two different data records (D1, D2, ...), each data record (D1, D2, ...) containing at least one parameter (P1, P2 ...), one data record (D2, Dx) being selected to accomplish a cyclic data transmission, and where the parameters (P1-Pm, Px) contained in the selected data record (D2, Dx) are transmitted cyclically.

Description

The present invention relates to a method for data transmission between an IO-Link device and an IO-Link master in accordance with the IO-Link standard, which is defined in the IEC 61131-9 standard.

The connection via IO-Link has now proven itself in automation technology for connecting intelligent sensors and actuators. IO-Link relates to a serial point-to-point connection via which data is transmitted between a so-called IO-Link master and one or more connected IO-Link devices (device) as a slave. For example, fieldbus modules or PLC interface modules are available as masters, which have one or more ports for connecting IO-Link devices. The IO-Link master represents the connection between the IO-Link device and the respective automation system and communicates, for example, via a fieldbus.

The IO-Link devices, on the other hand, are sensors, actuators, control elements or display units. The IO-Link devices are described using so-called IODD description files (IO-Link Device Description), which contain, for example, device-specific configuration parameters of the respective IO-Link device.

Various circuits and methods for communication according to the IO-Link standard are, for example, from the documents EP2211464A1 , DE102012009494A1 or DE102014106752A1 known.

Various IO-Link adapters have again been proposed for connecting field devices that are not IO-Link capable to an IO-Link master, for example in the documents DE102014118172B3 , DE202009010293U1 or DE102016221662B4 disclosed.

Basically, four types of data can be transmitted via IO-Link: process data, the value status of each port, device data and events. Process data relate to values determined using the IO-Link devices, in the case of sensors, for example, values for the process variable determined by the sensor. The value status of a port indicates whether the process data is valid or invalid. Various parameters, identification data and diagnostic information are summarized under device data. In turn, events can be error messages, warnings or maintenance information.

The process data and the value status of each IO-Link device are usually transmitted cyclically in a data telegram, with the process data size being determined by the respective IO-Link device. Basically, process data from 0-32 bytes are possible. Device data and events, on the other hand, are only exchanged acyclically and sometimes only at the request of the IO-Link master.

Basically, the bandwidth for data transmission is limited according to the IO-Link standard, so that the transmission speed correlates with the amount of data to be transmitted cyclically. However, different applications require that different data are regularly available. Accordingly, the amount of data to be transmitted cyclically can be selected to be large, which has a disadvantageous effect on the speed of the transmission. Or many values can only be transferred acyclically, but this is also accompanied by a significant loss of speed.

The present invention is therefore based on the object of optimizing the data transmission in accordance with the IO-Link standard with regard to the transmission speed.

This object is achieved by a method for data transmission between an IO-Link device and an IO-Link master, the data transmission being defined in the IO-Link standard, at least two different data sets being provided, each data set containing at least one parameter , wherein a data set is selected to accomplish a cyclical data transmission, and wherein the parameters contained in the selected data set are transmitted cyclically.

In connection with the present invention, parameters are understood to mean, for example, process data, information on the value status, device data and events. A parameter can therefore be any size to be transmitted in accordance with the IO-Link standard. Each data record contains at least one parameter, preferably at least two different parameters. For example, each data record contains at least partially different parameters. Consequently, two data records differ in at least one of the parameters contained in each case. Data sets that are particularly suitable for different applications can thus be defined.

According to the invention, different data records are provided which contain different parameters. Accordingly, suitable parameters are assigned for different applications, different IO-Link devices and IO-Link masters put together a data record, which is then transmitted cyclically. For a specific application, the relevant parameters and sizes are available via cyclical data transmission with an optimized transmission speed.

It is advantageous if a device description file (IODD) is provided for each data record. Each IODD is preferably specially adapted to the respective data set.

It is advantageous if at least one device description file is stored on a storage medium or in a network. In this case, the respective IO-Link device and / or the respective IO-Link master are able to access the storage medium or the network.

The storage medium can either be a local storage in the IO-Link device or IO-Link master or a central storage.

It is also advantageous if a changeable device description file is provided, which is adapted to the selected data record. The device description file can preferably be changed individually and adapted to the respectively selected data record.

In a preferred embodiment, at least one parameter is a value for a, in particular physical, chemical or biological process variable of a medium, a statement about the state of the IO-Link device, time information, or an earlier point in time determined value for a parameter. The statement about the status of the IO-Link device can be, for example, a status message, a statement about the quality of a measured value or a diagnosis of the IO-Link device. If a value determined at an earlier point in time for one of the parameters, that is to say a backup, is transmitted, a comparison can be made, for example, in a higher-level unit of a value currently and previously determined for the respective parameter. Based on the comparison, a statement about the IO-Link device can also be generated.

A particularly preferred embodiment provides that the selected data record is selected as a function of a value for a selection parameter. This means that several data records are provided and each associated with a value for the selection parameter. Depending on the respective application, one of the predefined data records can then be selected by setting a value for the selection parameter.

In this regard, it is advantageous if the value for the selection parameter is set using a dip switch.

However, it is also conceivable to set the value for the selection parameter by entering a value in software.

In a particularly preferred embodiment, the selected data record is selected from a list comprising at least two different data records. So at least two different data sets are compiled. Depending on the application, the appropriate preconfigured data record can be selected.

In another particularly preferred embodiment, the selected data set is compiled from at least two different parameters. A data record is therefore individually compiled and selected. This allows a higher degree of adaptation to the respective application compared to preconfigured data sets. In return, the effort to select the selected data record is somewhat higher. In particular, a suitable description file must also be created for each compiled data record.

With regard to the compilation of a data record, it is advantageous if the parameters of the selected data record are selected depending on a process in which the IO-Link device is used. In this way, an application-specific and individually adapted data record can be defined, which is then used for cyclical data transmission. As a result, the data transmission can be optimized both with regard to the transmission speed and with regard to the sizes required in each case, which are available by means of the individual parameters.

In a further embodiment of the method according to the invention, the parameters of the first data record are output in a first parameter type and the parameters of the second data record in a second parameter type. The data types are typically used data types such as float, integer or string. It is therefore not only conceivable that the parameters of different data records differ at least partially from one another, but also that different data records are based on different data types.

• 1 eine schematische Darstellung einer zyklischen Datenübertragung gemäß dem IO-Link-Standard, und
• 2 verschiedene Ausgestaltungen des erfindungsgemäßen Verfahrens, wobei
  1. (a) der ausgewählte Datensatz anhand eines Auswahlparameters aus einer Liste ausgewählt wird, und für jeden Datensatz eine IODD bereitgestellt wird
  2. (b) eine anpassbare IODD bereitgestellt wird, und
  3. (c) der ausgewählte Datensatz anwendungsspezifisch zusammengestellt wird

The present invention is described in more detail with reference to the following figures. It shows:

• 1 a schematic representation of a cyclic data transmission according to the IO-Link standard, and
• 2nd different configurations of the method according to the invention, wherein
  1. (a) the selected data set is selected from a list on the basis of a selection parameter, and an IODD is provided for each data set
  2. (b) a customizable IODD is provided, and
  3. (c) the selected data record is compiled application-specifically

In the figures, the same elements are provided with the same reference numerals.

1 relates to a schematic representation of a cyclic data transmission between an IO-Link device 1 and an IO-Link master 2nd according to the IO-Link standard. A data record D comprising one or more parameters P is transmitted. A suitable IODD is also provided.

According to the invention, at least two different data records D1, D2, ... are provided. Each data record D1, D2, ... contains at least one parameter P1 P2 ..., the parameters of the different data records D1, D2 differing from one another at least in part. Furthermore, according to the invention, a data record D1, D2 is selected to accomplish the cyclic data transmission. So only the parameters contained in the selected data record are transferred cyclically.

2nd illustrates, by way of example, some preferred configurations of the method according to the invention in relation to the provision and selection of the different data records D1, D2.

According to the in 2a In the embodiments shown, different data records D1, D2, ... Di are provided, each containing different parameters P1-Pn, P1-Pm, ... P1-Pk. These data records D1-Di are preconfigured for the embodiment shown here and predefined accordingly. According to the invention, one of the specified data records D1-Di is selected and then used for the cyclic data transmission. The selected data record D1-Di (here D2) is selected here using a selection parameter Pa. A corresponding value for the selection parameter Pa is assigned to each data record D1-Di. By setting a certain value for the selection parameter Pa, the selected data record D2 is selected accordingly. The respective value for the selection parameter Pa can be set, for example, by means of a dip switch or within software.

Furthermore, a description file IODD1, IODD2, ... IODDi is provided for each data record D1, D2, ... Di. The description files IODD1, IODD2, ... IODDi can, for example, on a suitable storage medium 3rd be deposited. However, it is also conceivable to store the description files IODD1, IODD2, ... IODDi in a network, to which the IO-Link master stores them 2nd and / or IO-Link devices can be accessed.

In the in 2 B shown embodiment, however, a variable description file IODDx is provided, which is suitably configurable depending on the selected data set D2.

Another preferred embodiment is in 2c shown. Instead of selecting preconfigured data records D1, D2 ... from a list, it is also conceivable to put together a data record Dx appropriately. For this purpose, the relevant parameters P1, P2, ... Px are determined, for example depending on the respective application. The use of a variable description file IODDx, as in connection with, is particularly suitable here 2 B described.

Reference list

1

IO-Link device

2nd

IO-Link master

3rd

Storage

D, D1, D2, ..

record

D2, Dx

selected record

P, P1, P2, ...

parameter

IODD

Description file

Pa

Selection parameters

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2211464 A1 [0004]
• DE 102012009494 A1 [0004]
• DE 102014106752 A1 [0004]
• DE 102014118172 B3 [0005]
• DE 202009010293 U1 [0005]
• DE 102016221662 B4 [0005]

Claims (12)

Method for data transmission between an IO-Link device (1) and an IO-Link master (2), whereby the data transmission is defined in the IO-Link standard, at least two different data records (D1, D2, ...) are provided, each data record (D1, D2, ...) contains at least one parameter (P1, P2 ...), wherein a data record (D2, Dx) is selected to accomplish a cyclical data transmission, and wherein the parameters (P1-Pm, Px) contained in the selected data record (D2, Dx) are transmitted cyclically. Procedure according to Claim 1 , whereby a device description file (IODD1, IODD2, ...) is provided for each data record (D1, D2, ...). Procedure according to Claim 2 , the device description file (IODD1, IODD2, ...) being stored on a storage medium (3) or in a network. Procedure according to Claim 2 or 3rd , whereby a changeable device description file (IODDx) is provided, which is adapted to the selected data record (D2, Dx). Method according to at least one of the preceding claims, wherein at least one parameter (P1, ...) is a value for a, in particular physical, chemical or biological process variable of a medium, a statement about the state of the IO-Link device, is time information or a value for a parameter determined at an earlier point in time. Method according to at least one of the preceding claims, wherein the selected data set (D2, Dx) is selected as a function of a value for a selection parameter (Pa). Procedure according to Claim 6 , the value for the selection parameter (Pa) being set by means of a dip switch. Procedure according to Claim 6 , the value for the selection parameter (Pa) being set by entering a value in software. Method according to at least one of the preceding claims, wherein the selected data record (D2, Dx) is selected from a list comprising at least two different data records (D1, D2, ...). Method according to at least one of the preceding claims, wherein the selected data set (Dx) is composed of at least two different parameters (P1, P2, ... PX). Procedure according to Claim 10 , whereby the parameters (P1, P2, ... PX) of the selected data record (Dx) are selected depending on a process in which the IO-Link device (1) is used. Method according to at least one of the preceding claims, wherein the parameters (P1, ... Pn) of the first data set (D1) in a first parameter type and the parameters (P1, ... Pm) of the second data set (D2) in a second parameter type be issued.

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