5 Use cases ToC Previous Next

5.3 Use Case description ToC Previous Next

5.3.2 Asset management ToC Previous Next

5.3.2.1 General ToC

The following asset management use-cases focus mainly on running applications and plants. During the commissioning phase changes in the assets are normal. The asset management phase begins after the acceptance tests of the commissioning phase.

5.3.2.2 PROFINET basics ToC

The following chapters give a brief introduction to relevant PROFINET objects and services, which are used in the scope of the OPC UA integration use cases. A detailed definition of these terms can be found in documents from Chapter 2 or several printed documents which are available at www.profinet.com. Nevertheless, the reader of this document should be able to understand the basic PROFINET concepts without knowledge of all the details.

It is important, that the support of some PROFINET information below is not mandatory. Therefore, an optimal usability and features coverage can be achieved with devices which implement a maximum of optional PROFINET features. The requirement of the PROFINET specification is denoted by the capital (PN-M) for mandatory or (PN-O) for optional.

5.3.2.2.1 General ToC

The following information is general for all PROFINET devices.

  • Device Information (PN-M): Information that is related to the device with the PROFINET connection to the network. Examples are VendorID, DeviceID, DCP type identification, DNS Name of Station and IP-Address.
  • Physical Topology (PN-M): PROFINET can discover the physical topology of installed devices as all devices exchange neighborhood information with the LLDP protocol.
  • Real Configuration (PN-M): The real configuration of a PROFINET device contains slots and subslots with modules and submodules plugged in the device independent from any controller connection. Each module/submodule is identified by a module/submodule identification number which must be unique in the scope of one DeviceID. One defined submodule is the representative of the device; one submodule is the representative of a module. Therefore, the submodule is the carrier of all information. Modules and submodules which are installed in the real configuration of the device can be discovered with a PROFINET service. These modules/submodules are the carrier of the asset information.
  • Expected Configuration (PN-M): The expected PROFINET configuration is the result of the PROFINET engineering in the configuration tool of the PLC. It contains the devices, modules, submodules which are configured in the engineering system of the PLC, downloaded to the controller and transferred to the devices during startup. The expected configuration can be read with a defined PROFINET service.
  • Module Diff Block (PN-M): The difference between the expected configuration and the real configuration. The reference to the difference is the expected configuration. The module diff block can be read with a defined PROFINET service.

    5.3.2.2.2 I&M ToC

    PROFINET defines Identification and Maintenance functions since PROFIBUS. As there is a long history, some restrictions in these data are possible. In general, I&M contain defined properties and values to identify the asset more precise as it is possible with IDs and without knowledge of the GSD file.

  • I&M0 – Electronic Faceplate (PN-M for device, PN-O for Modules): Version Information of the submodule like serial number, HW-Version and FW-Version. I&M0 data are read-only.
  • I&M1 – function and location (PN-O): A unique function and location of the device/submodule as visible strings. I&M1 data must be written by a PROFINET engineering tool or PLC before they can be used. The mapping to marking systems like IEC 81346 are in the responsibility of the user and not in scope of this document.
  • I&M2 – comment (PN-O): A comment to the device as visible string. I&M2 data must be written by a PROFINET engineering tool or PLC before they can be used.
  • I&M3 – installation date (PN-O): The installation date of the device. I&M3 data must be written by a PROFINET engineering tool or PLC before they can be used.
  • I&M4 – signature (PN-M and defined for Functional Safety): If the submodule is configured by an external safety configuration tool, this tool can write a signature of the parameter set in I&M4 data of the submodule. With its signature it is possible to discover differences between a stored parameter set of the engineering tool and a parameter set in the field. I&M4 is only defined for safety devices.
  • I&M5 – additional information (PN-O) Offers additional information about a communication module which is part on an IO device. If the device (e.g. a robot) is made by company A, and the communication module by company B, I&M0 contain information about the robot and company A, I&M5 contain information about the communication module and company B.

    5.3.2.2.3 Asset management in PROFINET ToC

    In addition to the above I&M data which are only bound to the PROFINET address elements slot/subslot, additional end customer requirements for enhanced asset management capabilities are incorporated in the PROFINET specification. Definition of PROFINET asset management objects sometimes use data types already defined by I&M properties. In addition to them other asset management properties are available. Asset information can be bound to slots and subslots to extend information, which cannot be modelled with I&M properties. Moreover, the PROFINET specification defines a level-tree of assets which objects are independent from the slot/subslot addressing scheme.

The following picture shows a possible example of asset management usage in a modular IO device.

readme_files/image015.png

Figure 11 – Asset management example modular IO

The green elements are the modules and submodules of the station carrying I&M information. Additional asset information like version info of the power supply, terminal blocks or connected sensors and actors can be described by means of asset management objects, which are not directly related to the slot/subslot model.

In addition to this example PROFINET AM can be used to manage all components with loadable software, which can be device or module firmware as well as application programs running on PLCs or robots.

The following asset management objects can be accessed via a defined acyclic read service.

  • AM_Info: The scope of the asset information, which can be “full information”, “firmware only” or “hardware only”.
  • AM_Location: The location of an asset within a device as 16 subsequent octets. The location can be either “slot/subslot” to extend I&M information or “level tree” to form hierarchical structures of assets.
  • IM_UniqueIdentifier: A 128-bit globally unique identification of the asset created by the manufacturer e.g. by means of ISO/IEC 9834-8:2014.
  • IM_Annotation: A manufacturer-specific identifier of the asset such as the asset’s name as Unicode string8 with the length of 64 octets.
  • IM_OrderID: The order ID of the asset as UnicodeString8 with the length of 64 octets.
  • AM_SoftwareRevision: The edition of the software of the asset as UnicodeString8 with 64 octets.
  • IM_Software_Revision: Software revision in a special I&M coding of VisibleString[9].
  • AM_HardwareRevision: The edition of the hardware of the asset as UnicodeString8 with 64 octets.
  • IM_Hardware_Revision The hardware revision in I&M coding.
  • IM_Serial_Number: A unique production number of the asset set by the manufacturer as VisibleString16.
  • AM_DeviceIdentification: The unique device identification in the address space of an organization like VendorID & DeviceID for PI. Or OUI for IO-Link.
  • AM_TypeIdentification: Used to identify the family of the asset and assigned by the manufacturer like “IO controller”, “IO device”, “IO-Module”. Standard and manufacturer specific values are defined in [3].

    5.3.2.3 Architecture ToC

    The architecture from Chapter 5.2.1 can be specialized for the usage within asset management. An asset management tool as OPC UA Client is connected to an OPC UA Server located in a PLC, Edge gateway or IO device. The PLC acts as IO controller for the underlying PROFINET system. The Edge gateway is scanning the underlying assets by means of DCP and implicit Read Services.

readme_files/image016.png

Figure 12 – Architecture of Asset Management

5.3.2.4 End User Requirements ToC

The following end customer requirements are relevant for asset management. A more detailed description of these use cases can be found in [PN TAD].

The requirements are written from the perspective of an asset management tool user.

Table 8 – Asset Management User Requirements

ID Name Details
AM1 Unique Identification The asset must have a unique Identification in the namespace of all installed assets independent whether the asset is installed in a cell or a machine.
AM2 Hardware and Firmware version management Hardware and Firmware versions of the installed equipment should be discovered or compared with possible white-lists or black-lists.
AM3 Application version management The application programs running on PLCs, robots or drives are also versioned and part of the asset management. Versioning for these applications shall be visible. This requirement can be solved in a comparable way then firmware version management.
AM4 Asset changed End users want to know, if an asset is changed.
AM5 Asset installed A new asset is installed in the cell or machine.
AM6 Asset removed A new asset is removed from the cell or machine.
AM7 Asset localization changed The physical location of an asset was changed. E.g. moved from one machine to another.
AM8 Machine part discovery Usually the assets installed in a machine are in the responsibility of the machine builder. If some of these assets are replaced by the operator of a machine, the asset discovery of integrated assets is required.
AM9 PROFIsafe Device parameters changed The OEM wants to know, if PROFIsafe Device parameters are changed by an external engineering tool in the device and/or in the engineering system of the IO controller for startup parameters.
AM10 Asset location changed The asset is moved to a different place in the asset hierarchy.
AM11 I&M Write The OEM wants to set writeable I&M1…3 parameters via OPC UA independent from the configuration in the engineering system of the IO controller.
AM12 Network parameter check The end user wants to know, if all installed PROFINET devices follow specific rules for their network parameters given by the OEM. Network parameters are:
* PROFINET Name of Station
* IP-Address
* Subnet mask
* Default gateway
* Allowed cycle times
* Allowed data hold times
AM13 Docking Devices PROFINET devices which are connected and disconnected to the network at runtime in normal operation.

5.3.2.5 Asset discovery ToC

The following use case describes the discovery of installed PROFINET assets.

Table 9 – Use case - Asset Discovery

Goal The end user wants to discover all installed assets within a cell. All available information shall be discovered.
Implements AM1, AM8, AM12
Preconditions All PROFINET components are configured and connected to the network.
Station Names and IP-Addresses of the devices can be set.
The Tag-Function and Tag-Location in I&M1 and asset management data are available.
The PLC/Edge Gateway is scanning the underlying network continuously with DCP-Identify and PROFINET read services to get all relevant asset information. For details see [1].
OPC UA Mapping AM tool connects the OPC UA Server in the EGW/PLC/Device.
The OPC UA information model in the EGW is built based on the found devices, modules and submodules of the last scan cycle. The required I&M and Asset information are read with the corresponding PROFINET services in the context of an implicit or device access AR.
The OPC UA information model in a PLC is built corresponding to the real configuration downloaded from the engineering system of the PLC. The required I&M and Asset information are read with the corresponding PROFINET services in the context of the already established IO-AR.
The OPC UA information model in a device is build corresponding to the real configuration plugged by the local device application. The required I&M and Asset information are implemented according the local device application.
Remarks When there is no station name, the MAC address shall be used as BrowseName. If those devices get a correct name, they are visible as a different entity under their station name as the OPC UA browse name shall be unique.

5.3.2.6 Asset change detection ToC

The following chapter describes criteria to detect changes in the assets. They may be useful to implement corresponding functionalities in the asset management tool.

5.3.2.6.1 Asset information changed ToC

The user wants to be informed if assets in the plant or machine were changed. The following table describes criteria to detect changes.

Implements AM4.

Table 10 – Criteria for asset information changed

Changed asset Criteria PROFINET Service
Device Software Version changed AKZ/OKZ changed I&M0:SoftwareVersion
I&M1: AKZ/OKZ
Module Submodule Software Version changed AKZ/OKZ changed I&M0:SoftwareVersion
I&M1: AKZ/OKZ
Asset Software Version changed AKZ/OKZ changed Will be part of a next version of the companion specification

5.3.2.6.2 Asset changed ToC

The user wants to be informed if assets in the plant or machine were changed. The following table describes criteria to detect changes.

Implements AM4.

Table 11 – Criteria for asset exchange

Changed asset Criteria PROFINET Service
Device Serial number changed IM_SerialNumber of the DAP
Module Submodule Serial number changed IM_SerialNumber of the module/submodule
Asset Serial number changed IM_SerialNumber of the asset

5.3.2.6.3 Asset installed ToC

The user wants to be informed if assets in the plant or machine were added. The following table describes criteria to detect changes.

Implements AM5.

Table 12 – Criteria for added assets

Added asset Criteria PROFINET Service
Device Device with unknown MAC address in the network DCP-Identify-All
Module Submodule Real configuration contains a new module/submodule RecordRead RealIdentificationData for all API’s
Asset Asset list contains a new entry RecordRead AM_Info

5.3.2.6.4 Asset removed ToC

The user wants to be informed if assets in the plant or machine were removed. The following table describes criteria to detect changes.

Implements AM6.

Table 13 – Criteria for asset removal

Removed asset Criteria PROFINET Service
Device Device list smaller than previous scan DCP-Identify-All
Module Submodule Real configuration contains less modules/submodules RecordRead RealIdentificationData for all API’s
Asset Asset list contains less modules/submodules RecordRead AM_Info

5.3.2.6.5 Docking devices ToC

Special cases in PROFINET are devices which are connected and disconnected to the network at runtime, like devices installed on a tool gripped by a robot. It is not guaranteed, that docking devices can be fully discovered by the scan cycle of Edge gateways. An IO controller may show information of docking devices in the local OPC UA Server.

5.3.2.6.6 Firmware or application program updated ToC

One important use case of asset management is the detection of firmware updates in the plant or machine as well as a version change in a programmable application running on a PLC, robot or drive. The following table describes criteria to detect changes.

Implements AM2, AM3.

Table 14 – Criteria for firmware or application program update

Updated asset Criteria PROFINET Service
Device IM_SoftwareRevision of the submodule representing the device has a changed value. RecordRead I&M0FilterData RecordRead I&M0
Module Submodule IM_SoftwareRevision of module/submodule has a changed value. The modules/submodules with explicit I&M data can be found asking for I&M0FilterData. RecordRead I&M0FilterData RecordRead I&M0
Asset IM_SoftwareRevision or AM_SoftwareRevision of asset has a changed value RecordRead AM_Info

5.3.2.6.7 PROFIsafe device parameters changed ToC

Sometimes it is important to know, if a safety parameter of a device in the plant or machine, set by an engineering tool, was changed. The following table describes criteria to detect changes.

Implements AM9.

Table 15 – Criteria for safety device parameter change

Changed Parameter Criteria PROFINET Service
Device IM_Signature of DAP has a changed value RecordRead I&M4
Module Submodule IM_ Signature of module/submodule has a changed value RecordRead I&M4
Asset Not available  

5.3.2.6.8 Asset Localization changed ToC

As special case for asset management is a change of a device in the physical topology. This is sometimes the case while finding errors in the field by exchange of devices.

Implements AM10.

Table 16 – Criteria for topology change

Topology change Criteria PROFINET Service
Device moved Changed neighborhood information of a device with a known MAC address and/or SerialNumber DCP_Identifiy RecordRead PDRealData
Device added Device with an unknown MAC address in physical topology DCP_Identifiy RecordRead PDRealData
Device removed New physical topology without a device which was there before DCP_Identifiy RecordRead PDRealData

Previous Next