This OPC UA Interface is used to represent the traffic specification of a TSN stream. The IIeeeBaseTsnTrafficSpecificationTypeis formally defined in Table 10.

Table 10– IIeeeBaseTsnTrafficSpecificationType definition

Attribute

Value

BrowseName

IIeeeBaseTsnTrafficSpecificationType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

Modelling Rule

Subtype of the BaseInterfaceTypedefined in OPC 10000-5

HasComponent

Variable

MaxIntervalFrames

UInt16

BaseDataVariableType

Mandatory

HasComponent

Variable

MaxFrameSize

UInt32

BaseDataVariableType

Mandatory

HasComponent

Variable

Interval

UnsignedRationalNumber

BaseDataVariableType

Mandatory

Conformance Units

BNM TSN Config

The MaxFrameSizeof DataType UInt16 specifies the maximum size frame that will be sent by a Talker for this Stream (see IEEE 802.1Q-2018clause 35.2.2.8.4a).

Note: According to 802.1Q MaxFrameSizeonly counts the number of bytes of the Ethernet payload without the media specific framing bytes. (i.e. without 8-byte preamble, 14-byte IEEE 802.3 header, 4-byte IEEE 802.1Q priority/VID Tag, 4-byte CRC, 12-byte inter frame gap). Same rules apply for counting MaxBytesPerInterval.

The MaxIntervalFramesof DataType UInt16 Variable specifies the maximum number of frames that will be sent during an Interval.(see IEEE 802.1Q-2018, clause 35.2.2.8.4b, “MaxIntervalFrames” or IEEE 802.1Qcc-2018, clause 35.2.2.10.6, “MaxFramesPerInterval”)

Intervalof DataType UnsignedRationalNumberdefines the time period of the TSN Stream in nanoseconds. In that interval a specified number of frames (MaxIntervalFrames) with a maximum payload size per frame (MaxFrameSize) and a maximum total number of bytes (MaxBytesPerInterval) will be transmitted. The Interval therefore shall either represent the “class measurement interval” as used for AVB based Streams (see IEEE 802.1Q-2018clause 35 or the “Interval” parameter used in the TrafficSpecification group in IEEE 802.1Qcc-2018clause 46.2.3.5.1.