Abstract: A data packet is provided that includes a synchronization field and an acknowledgement field indicative of an acknowledgement of receipt of a prior data packet. The data packet also includes a response field that includes information indicative of a system fault, a header field, and a sequence number field that includes a number assigned to the data packet. The data packet further includes a data field, an end of packet field, and an error-checking field. Methods and computer program products are provided that, in some implementations, include retransmitting packets if the acknowledgement field in a received data packet is a no acknowledgement (NAK) and/or placing a node into a safe state in response to a fault signal that is included in the received data packet.

Abstract: Methods, apparatus, and computer program products that synchronously communicate data packets between a first node and a second node. Data packets are transmitted from the first node without waiting for acknowledgment of receipt by the second node. Acknowledgment of receipt of a given data packet is subsequently received at the first node. The acknowledgement is received substantially at a predetermined time following transmission of the given data packet. The acknowledgement indicates that the second node received the given data packet uncorrupted.