RSC PROFINET Services

The PROFINET component can be extended via interfaces for PROFINET services. You can use one interface for acyclic communication (RecordRead, RecordWrite). The interface is available via the RSC protocol. The parameter data, diagnostic information, and status information (PDI = Parameters, Diagnostics and Information) of a PROFINET device can be read or written with the RSC service. Acyclic communication is suitable for the exchange of data that does not recur cyclically.

Note: The execution of RSC services can take some time. For this reason, avoid direct calls from ESM tasks that are scheduled for real-time execution.

IAcyclicCommunicationService

The IAcyclicCommunicationService RSC service in the Arp/Io/ProfinetStack/Controller/Service namespace for acyclic communication makes the following methods available:

RecordRead:
Enables parameters, diagnostics and information of a PROFINET device to be read
RecordWrite:
Enables parameters, diagnostics and information of a PROFINET device to be written

RecordResult RecordRead(const RecordParam& recordParam, std::vector<uint8>& data)
RecordResult RecordWrite(const RecordParam& recordParam, const std::vector<uint8>& data)

Parameters are necessary for executing RecordRead and RecordWrite. The RecordParam structure is used for transmitting the input parameters. The structure provides two ways of addressing a module:

Approach 1: Addressing via the ID
Approach 2: Addressing via an address that is made up of DeviceName, Slot and Subslot

If one approach for addressing is picked, the parameters for the other approach must be 0 or empty.

The RecordParam structure has the following elements:

Parameter	Description
`uint16` Id	Node ID of the submodule The ID is assigned automatically. It can be viewed in PLCnext Engineer (approach 1). For this, open the submodule list of the PROFINET submodule node: To determine the ID, you can also use the `AddressToID` method of the `IAddressConversionService.hpp` service.
`RscString<512>` DeviceName	Device name Name of the device that is to be addressed (approach 2)
`uint16` Slot	Device number (approach 2)
`uint8` Subslot	Subdevice number (approach 2)
`uint16` Index	Object index
`uint8` Length	Maximum data amount; specifies the maximum amount of data to be written in bytes (`RecordRead`) or the amount of data that is to be written to an object (`RecordWrite`).

The return values are written to the RecordResult structure. The structure has the parameters below. Further information on the parameters is available in the PROFINET v2.3 specification.

boolean ServiceDone
uint8 ErrorCode
uint8 ErrorDecode
uint8 ErrorCode1
uint8 ErrorCode2
unit16 AddData1
unit16 AddData2

ErrorCode1

Error code	Description
`0`	No errors
`0xF0`	Internal error The error can be evaluated more precisely via ErrorCode2.
Further error codes	If a value other than `0xF0` or `0` is displayed in the `ErrorCode1` element, the error is described in the `ErrorCode`, `ErrorDecode`, `ErrorCode1`, `ErrorCode2`, `AddData1`, and `AddData2` fields by the PROFINET specification.

ErrorCode2

Error code	Description
`0x03`	`InvalidAddress` ID or DeviceName/Slot/Subslot is invalid.
`0x15`	`RecordReadFailed` RecordRead failed. This error can occur, for example, if several devices simultaneously attempt to execute “RecordRead” on one device.
`0x16`	`RecordWriteFailed` RecordWrite failed. This error can occur, for example, if several devices simultaneously attempt to execute “RecordWrite” on one device.
`0x17`	`Timeout` No confirmation was received.

Data that is read (RecordRead) or data that is to be written (RecordWrite) is transferred in a type unit8 vector (data). A description of the data (maximum size, type, etc.) of the object description is available in the PROFINET v2.3 specification.

You need the following headers to use the service. If necessary, include them via the #include command:

Arp/Io/ProfinetStack/Controller/Services/IAcyclicCommunicationService.hpp
Arp/Io/ProfinetStack/Controller/Services/AcyclicCommunicationServiceProxyFactory.hpp
Arp/Io/ProfinetStack/Controller/Services/RecordParam.hpp
Arp/Io/ProfinetStack/Controller/Services/RecordResult.hpp