[AUTOSAR 11 communication related mechanism]

1. Signal Groups Signal group

 Put some signals with similar functions into a group to facilitate management .

2. Update Bit Update bit

 stay Signal One in lieutenant general bit Reserved for use as Update Bit

• This bit is specifically used to indicate whether the signal has been updated by the application layer , If it hasn't been updated for a long time , Start timeout processing .

3. Notification Mechanisms A notification mechanism

Notification type

• Receive success notification
• Send success notification
• Timeout notification
• Error notification
• Invalidation notice
• Update bit notification

Notification has an important attribute ：（ This property is in Communication->PDUs Configured in ）

• Notify immediately （Immediate）： It's acceptance / The successful sending immediately interrupts the entry notification function
• Delayed notification （deferred）： Not immediately , Next time in Task Call in Com_MainFunctionRx() perhaps Com_MainFunctionTx() Trigger notification when

4. Deadline Monitoring

4.1 Timeout monitoring

Timeout monitoring can be divided into two levels ：

• IPDU level ： When one Rx IPDU No valid data is received within the specified time , Start timeout processing
• Signal level ： That's what we said before Update Bit The way , If not received Update Bit, Start timeout processing
• IPDU Of Timeout Time The source of is in IPDU Medium Signal Minimum Timeout Time. For example, that is IPDU There are two Signal,Signal A Of Timeout Time=100ms,Signal B Of Timeout Time=50ms, So this IPDU Of Timeout Time = 50ms

4.2 timeout handler

COM Timeout processing for

•	 After timeout, there will be a timeout Notification Called ：Rte_COMCbkTOut_<ComSignalName>
•	 Optional ： You can choose to reset the timeout signal to its initial value （ Need configuration ComRxDataTimeoutAction）

RTE Timeout processing for

•	 After timeout, a Runnable To deal with it 
•	 In use related Rte_Read_<Pp>_<De> Will return an error RTE_E_MAX_AGE_EXCEEDED
•	 In the use of Rte_IRead In this way Buffer Type of S/R At the interface , The state can be determined by Rte_IStatus decision 

5. Invalidation Failure mechanism

5.1 Failure mechanism

When one Signal Groups Any one of them Signal When it is set to invalid , Whole Groups It is set to be invalid .
Half valid and half invalid Signal Groups appear .
The failed signal can pass Rte_Inmalidate(explicit API) perhaps Rte_IInvalidate(implicit API) To send an invalid value .

5.2 Failure treatment

There are three ways to deal with failure ：

•	Keep:  Keep the original value unchanged 
•	Replace:  Replace with an initial value 
•	None:  Do nothing , It means that this failure mechanism doesn't work