Synchronous data communication

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.