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.

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.

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.

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.

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.

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_RevisionThe 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].

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.

Figure 12 – Architecture of Asset Management

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.

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.

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

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 changedAKZ/OKZ changed	I&M0:SoftwareVersion I&M1: AKZ/OKZ
ModuleSubmodule	Software Version changedAKZ/OKZ changed	I&M0:SoftwareVersion I&M1: AKZ/OKZ
Asset	Software Version changedAKZ/OKZ changed	Will be part of a next version of the companion specification

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
ModuleSubmodule	Serial number changed	IM_SerialNumber of the module/submodule
Asset	Serial number changed	IM_SerialNumber of the asset

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
ModuleSubmodule	Real configuration contains a new module/submodule	RecordRead RealIdentificationData for all API’s
Asset	Asset list contains a new entry	RecordRead AM_Info

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
ModuleSubmodule	Real configuration contains less modules/submodules	RecordRead RealIdentificationData for all API’s
Asset	Asset list contains less modules/submodules	RecordRead AM_Info

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.

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&M0FilterDataRecordRead I&M0
ModuleSubmodule	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&M0FilterDataRecordRead I&M0
Asset	IM_SoftwareRevision or AM_SoftwareRevision of asset has a changed value	RecordRead AM_Info

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
ModuleSubmodule	IM_ Signature of module/submodule has a changed value	RecordRead I&M4
Asset	Not available

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_IdentifiyRecordRead PDRealData
Device added	Device with an unknown MAC address in physical topology	DCP_IdentifiyRecordRead PDRealData
Device removed	New physical topology without a device which was there before	DCP_IdentifiyRecordRead PDRealData