The Action specific use of PubSub configuration parameters is defined in Table 84.

Note that the reliability of the protocol depends on the QoS levels supported by the protocol. Any Broker-based middleware that is using a QoS of AtLeastOnce or greater is reliable (see 6.4.2.5.4). Broker-less middle is not reliable if it does not support any DatagramQoS (see 6.4.1.2.6).

Table 84 – Action specific use of parameters

PubSubComponent

Parameter

Description

PubSubConnectionDataType

ReaderGroups

Readers are not used for Actions.

WriterGroupDataType

PublishingInterval

The value is 0 for reliable transport protocols.

The value shall be larger than 0 for non-reliable transport protocols.

The Requestor and Responder resends Action messages that have not been acknowledged by the receiver with this frequency.

KeepAliveTime

This value is not used and set to 0.

HeaderLayoutUri

For JSON messages the JSON-NetworkMessage header layout URI is used (see A.3.4).

For UADP messages this value is UADP-Dynamic header layout URI is used (see A.2.2).

BrokerWriterGroupTransportDataType

QueueName

The address that the Requestor uses to send requests to the Responder.

RequestedDelivery‌Guarantee

Shall be AtLeastOnce or better

UadpWriterGroupMessageDataType

SamplingOffset

Always -1.

NetworkMessageContentMask

Bit 0: PublisherId is always 1

JsonWriterGroupMessageDataType

NetworkMessageContentMask

Bit 0: NetworkMessageHeader is always 1.

Bit 1: DataSetMessageHeader is always 1.

Bit 2: SingleDataSetMessage is always 0.

Bit 3: PublisherId is always 1

Bit 5: ReplyTo is is always 0.

DataSetWriterDataType

DataSetFieldContentMask

Always 0.

KeyFrameCount

Always 0.

DataSetName

The name of the ActionMetaData.

UadpDataSetWriterMessageDataType

DataSetMessageContentMask

Bit 1: PicoSeconds is always 0.

Bit 2: Status is always 1, however, it is not sent in requests.

JsonDataSetWriterMessageDataType

DataSetMessageContentMask

Bit 2: SequenceNumber is always 0.

Bit 4: Status is always 1, however, it is not sent in requests.

Bit 5: MessageType is always 0.

Bit 8: PublisherId is always 0

DatagramWriterGroupTransport2DataType

MessageRepeatCount

Always 0

MessageRepeatDelay

Always 0

BrokerDataSetWriterTransportDataType

QueueName

Not used.

RequestedDelivery‌Guarantee

Not used.

MetaDataQueueName

The address used to send ActionMetaData Messages.