Packet communication apparatus

Abstract

A packet communication apparatus, which includes a CPU, a memory, and a packet communication circuit, acts as an interface between a network-connected controlled object and a network terminal that remotely monitors and controls the controlled object, and transmits and receives a packet between the controlled object and the network terminal, further includes a copy and operation unit that is a hardware unit for executing the checksum calculation to check for a packet error and the copy operation. The copy and operation unit performs the packet data copy operation and the checksum calculation simultaneously between a sending buffer/receiving buffer, formed in the memory and used by the packet communication circuit, and a work area used by a communication processing program, thus reducing the load of the CPU and increasing the communication processing speed.

1 . A packet communication apparatus comprising a CPU (Central Processing Unit), a memory, and a packet communication circuit, said packet communication apparatus acting as an interface between at least one network-connected controlled object and at least one network terminal that remotely monitors and controls the controlled object, said packet communication apparatus transmitting and receiving a packet between the controlled object and the network terminal,
 wherein said packet communication apparatus comprises communication middleware that causes said CPU to encapsulate data into a transmission packet and place the transmission packet in a work area in said memory,   wherein said packet communication apparatus further comprises a copy and operation unit that copies the transmission packet placed in the work area to a descriptor in said memory and, at the same time, executes a predetermined operation for the transmission packet, and   wherein said packet communication circuit transmits the transmission packet, which is obtained via a unique device driver and is stored in the descriptor in said memory, to the controlled object or the network terminal.   
     
     
         2 - 17 . (canceled)