Patent ID: 7356739

Claim:
A computer readable memory having stored therein a computer program for controlling operation of a distributed control system that comprises: a CPU for executing the program stored in the memory; a network controller connected to a network for sending a message that is to be sent onto the network; send data memory means for storing message data that are generated by said CPU, and are to be sent; send protocol processing means for receiving the message data that are stored in said send data memory means, and for processing said message data according to a predetermined send protocol to compose a message to be sent and to be transferred to said network controller; receive protocol processing means for receiving the message composed by said send protocol processing means, and processing the same according to a predetermined receive protocol to extract a data part from the message; and send data comparing means for comparing the message data stored in said send data memory means with the data part extracted from the message composed by said receive protocol processing means; wherein the program performs a control which causes said CPU to send the message through said network controller.