1 PLIN-API Documentation - PEAK-System

3.5 The LIN Receive Message PLIN API Documentation
3.5 The LIN Receive Message
The messages that a hardware sends and/or receives can be read from each connected client . The PLIN system forwards a
received message to the receive queue of each connected client, if the filter of the client accepts the message. An user can
read the messages from the receive queue of a client using the function LIN_Read ( see page 114) (.NET: Read ( see
page 61)) or using LIN_ReadMulti ( see page 114) (.NET: ReadMulti ( see page 62)).
The interpretation of a received message is the same for both a Master and a Slave. In slave-mode, an external Master is
responsible for sending the Frame-Header. In master-mode, the hardware itself is responsible for sending the Header.
A Receive Message contains the following elements:
Type
Represents the type of a received Message. The Type is defined as TLINMsgType ( see page 39) and can be one of the
following values:
• mstStandard: A message with data.
• mstBusSleep: A message meaning that the bus state has changed to Bus-Sleep ( The bus is recesive for at least 4
seconds). Only the Timestamp and Hardware Handle within this message is valid.
• mstBusWakeUp: A message meaning that a Wake-Up Impulse was received while the hardware was in Sleep state (data
byte F0h). Only the Timestamp and Hardware Handle within this message is valid.
• mstAutobaudrateTimeOut: A message meaning that a Baud-Rate Recognition process started before, got a timeout and
was unsuccessful. Only the Timestamp and Hardware Handle within this message is valid.
• mstAutobaudrateReply: A message that is a response to a Baud-rate Recognition process started before. The Timestamp
of this message is valid. The data bytes 0 (lsb) to 3 (msb) contain information about the duration of 8 data bits in
microseconds (the Sync Byte is measured).
• mstOverrun: A message indicating that the receive buffer of the hardware has been read out too late. The Timestamp of
this message is valid. The data bytes 0 (lsb) to 1 (msb) contain the current count of overrun errors.
• mstQueueOverrun: A message indicating that USB data packages are being lost or the sequence of those packages has
changed. The Timestamp of this message is valid. The data bytes 0 (lsb) to 1 (msb) contain the current count of
queue-overrun errors.
Frame Id
Valid only for messages of type mstStandard. Represents the ID of the received frame with parity bits.
Length
Represents the length of the data bytes contained within the received message. The length can be a value between 0 and 8.
Direction
Valid only for messages of type mstStandard. Represents the direction of a received Message. The Direction of the
message shows how the message must be interpreted.The Type is defined as TLINDirection ( see page 41) and can be
one of the following values:
• dirPublisher: A received message is a publisher message. See Message as Publisher ( see page 15).
• dirSubscriber: A received message is a subscriber message. See Message as Subscriber ( see page 17).
• dirSubscriberAutoLength: A received message is a subscriber message with automatic length. See Message as
Subscriber-AutoLength ( see page 18).
Checksum Type
Valid only for messages of type mstStandard. Gives information about the type of checksum expected within the message.
The checksum type is defined as TLINChecksumType ( see page 42) and the possible values are:
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