Patent ID: 8060668

Claim:
A device for communicating over a communication medium according to an industrial fieldbus protocol, the device comprising: a medium attachment unit (MAU) for receiving and transmitting messages on the communication medium according to the industrial fieldbus protocol; a central processing unit (CPU) for processing data contained in messages received and creating data to be contained in messages to be transmitted; and a communication controller for interfacing between the MAU and the CPU, the communication controller including a data queue and a queue of received message objects, the data queue for storing a plurality of messages received on the communication medium and including a write pointer and a read pointer, the write pointer corresponding to a location in the data queue for storing a new message received from the communication medium, the read pointer corresponding to a location in the data queue for reading a message from the data queue by the CPU, the received message objects each containing information about a corresponding message in the data queue, the information including event data for the message and attributes pertaining to a reception state of the message, wherein, as a message is received on the communication medium, a value of the write pointer is continuously transferred to an EndPosition attribute in a corresponding received message object.