Package jmri.jmrix.can

Interface CanFrame

All Known Subinterfaces:
CanMutableFrame
All Known Implementing Classes:
CanMessage, CanReply
@Immutable public interface CanFrame
Base interface for immutable messages in a CANbus based message/reply protocol.

It is expected that any CAN based system will be based upon basic CAN concepts such as ID/header (standard or extended), Normal and RTR frames and a data field.

"header" refers to the full 11 or 29 bit header; which mode is separately set via the "extended" parameter

  • Method Details

    • getHeader

      int getHeader()
      Get the CAN Frame header.
      Returns:
      header value

    • isExtended

      boolean isExtended()
      Get if the CAN Frame has an extended header.
      Returns:
      true if extended, else false

    • isRtr

      boolean isRtr()
      Get if the CAN Frame is an RTR Frame.
      Returns:
      true if RTR, else false

    • getNumDataElements

      int getNumDataElements()
      Get number of data bytes in the frame.
      Returns:
      0-8

    • getElement

      int getElement(int n)
      Get a single data byte in the frame.
      Parameters:
      n - the index, 0-7
      Returns:
      the data element value

    • monString

      default String monString()
      Get formatted monitor String. Includes if Frame is Extended. Header value at start. All values hex format. Only valid data elements are included.
      Returns:
      eg. "(1A ext) 81 EA 83 00 12"

    • getToString

      default String getToString()
      Get formatted toString. Does NOT include if Frame is Extended. All values hex format. Only valid data elements are included.
      Returns:
      eg. "[12] 81 EA 83"

    • appendHexElements

      default void appendHexElements(StringBuilder sb)
      Append the hex value of the data elements to a StringBuilder.
      Parameters:
      sb - to append the hex values to

    • isEqual

      default boolean isEqual(Object a, Object b)
      Compare 2 CanFrames for equality.
      Parameters:
      a - CanFrame to test
      b - CanFrame to test
      Returns:
      true if RTR, Extended, Header and Data elements match, else false

    • dataFramesEqual

      default boolean dataFramesEqual(CanFrame a, CanFrame b)
      Compare 2 CanFrame data elements for equality.
      Parameters:
      a - CanFrame to test
      b - CanFrame to test
      Returns:
      true if Data elements match, else false

    • extendedOrRtr

      default boolean extendedOrRtr()
      Check if the CAN Frame is extended OR RtR.
      Returns:
      true if either extended or RtR, else false