SNIP_CLASSIC_SYSTEMTEMPLATE_SECTION_3_3_5_4_LIN_Slave

3.3.5.4 LIN Slave AUTOSAR supports the definition of a stand-alone LIN slave1. In other words, it is possible to define an ECU Extract that contains the modeling of a LIN slave independently of the modeling of the LIN master. That said, the ability to define properties of the LIN slave in the context of the LIN master in the form of LinMaster.linSlave still exists and can be used where applicable. [TPS_SYST_05018] Semantics of meta-class LinSlave ⌈Meta-class LinSlave describes the existence of a LIN slave task in a LIN topology node. It describes the attributes of a single LIN slave node.⌋(RS_SYST_00022) [TPS_SYST_05019] Semantics of LinErrorResponse.responseError ⌈Each Lin slave has the ability to set an error bit in the response part of one specific LinUnconditionalFrame in the event of errors occurring on frame level. The error bit is modeled by means of a reference to an ISignalTriggering in the role LinErrorResponse.responseError.⌋(RS_SYST_00022) Please note that because the response error bit applies for frame errors the responsibility for setting the response error bit lies exclusively at the LinIf. In the event of such an error, the LinIf on the Lin slave Ecu calls Com_SendSignal () to set the value of the response error bit if applicable2 and thus the system model needs to foresee the existence of an ISignalTriggering for this purpose. Aside: on the Lin master, typically a piece of application software picks up the received error bit and uses it to e.g. increment a counter for debouncing purposes. If the counter exceeds a certain value in e.g. a given time interval the Lin master has to assume that a serious problem exists in the communication with this specific slave and react accordingly. 1In former versions of this specification document the properties of a LIN slave could only be defined in the context of the corresponding LIN master 2In principle, the LinIf on the Lin slave Ecu could directly patch the value of the response error bit into a Tx Pdu before sending but in this case the LinIf would have to pick the correct Pdu and patch it accordingly. In other words, the LinIf would replicate a certain amount of Com functionality. the usage of an ISignalTriggering significantly simplifies the implementation of the LinIf. System Template In terms of modeling, this means that if formally modeled application software on the Lin master exists that processes the error response bit (the receiving side of the error response bit) then a DataMapping to a SystemSignal that carries the response error bit needs to be defined. It is important to understand that application software on a Lin slave positively has no business of setting the value of the response error bit. In other words: on the sending side (i.e. the Lin slave), the application software is not affected and therefore there shall not be a DataMapping on the sending side. This relation motivates the existence of [constr_1656]. [constr_1656] No application-level write access to LinErrorResponse.responseError on Lin slave ⌈The SystemSignal referenced in the role systemSignal by the ISignal referenced by the ISignalTriggering that in turn is referenced in the role LinErrorResponse.responseError shall not be referenced by a DataMapping that allows for writing to the SystemSignal.⌋() Class <<atpVariation>> LinSlave Package M2::AUTOSARTemplates::SystemTemplate::Fibex::Fibex4Lin::LinTopology Note Describing the properties of the referring ecu as a LIN slave. Base ARObject, CommunicationController, Identifiable, LinCommunicationController, Multilanguage Referrable, Referrable Attribute Type Mult. Kind Note assignNad Boolean 0..1 attr This attribute has the ability to control whether the node configuration command ’Assign NAD’ is supported. configuredNad Integer 1 attr To distinguish LIN slaves that are used twice or more within the same cluster. functionId PositiveInteger 1 attr LIN function ID initialNad Integer 0..1 attr This attribute represents the initial NAD. linError Response LinErrorResponse 1 aggr Each slave node shall publish one response error in one of its transmitted unconditional frames. nasTimeout TimeValue 0..1 attr Value of the N_AS timeout. Unit: seconds. supplierId PositiveInteger 1 attr LIN Supplier ID variantId PositiveInteger 1 attr Specifies the Variant ID Table 3.39: LinSlave Class LinErrorResponse Package M2::AUTOSARTemplates::SystemTemplate::Fibex::Fibex4Lin::LinCommunication Note Each slave node shall publish a one bit signal, named response_error, to the master node in one of its transmitted unconditional frames. The response_error signal shall be set whenever a frame (except for event triggered frame responses) that is transmitted or received by the slave node contains an error in the frame response. The response_error signal shall be cleared when the unconditional frame containing the response_error signal is successfully transmitted. Base ARObject Attribute Type Mult. Kind Note responseError ISignalTriggering 0..1 ref This ISignal shall be taken to transport the responseError bit. Table 3.40: LinErrorResponse System Template