The Arbitration Field contains the previously mentioned identifier. The identifier in a Standard CAN 1.0, 2.0A, or 2.0B Data Frame is 11-bits long. The ID in an Extended Data Frame, which is allowed in the CAN 2.0B specification, is 29-bits long. Note here that Data Frames with Extended ID’s cannot be handled by CAN 1.0 or 2.0A hardware – or by CAN 2.0B hardware configured to accept only Standard ID’s.

