Method, system and program for the transmission of modbus messages between networks

An automation control system comprising:

• a fieldbus coupler operably connected to a Modbus communication bus;
• a Modbus device having an automation application, the Modbus device being operably connected to the fieldbus coupler via the Modbus communication bus;
• a Modbus protocol for communicating between the Modbus device and the fieldbus coupler;
• a network communication bus being operably connected to the field bus coupler;
• a network device being operably connected to the fieldbus coupler via the network communication bus;
• a network protocol for communication between the network device and the fieldbus coupler;
• the Modbus device and the network device being in communication with each other wherein the fieldbus coupler facilitates communication between the Modbus device and the network device by converting to and from the Modbus protocol and the network protocol, the Modbus protocol utilized by the automation application to one of query a network table in the network device and make a change to the network table at a specified offset address in the object dictionary.

A Modbus communication protocol for an automation system executing an automation application, the automation system comprising a fieldbus coupler being operably connected between a Modbus network having a Modbus device and a network having a network device including a network table, the Modbus communication protocol comprising:

• a Modbus message frame comprising:
• a header having an address identifier;
• a trailer having an error verifier;
• and,
• a Modbus function code encapsulated between the header and the trailer, wherein the automation application transmits a network message embedded within the Modbus function code to the network device table and utilizes the Modbus communication protocol to one of query the table and make a change to the table at a specified offset address in the table.

A system comprising:

• a device utilizing a first protocol having an embedded automation application, the device being operably connected to a communication bus;
• a fieldbus coupler operably connected to the automation application via the communication bus;
• a network being operably connected to the fieldbus coupler, the network including a first network node utilizing a second protocol having a table for holding data and parameters transmitted or received throughout the system;
• and,
• a bridge in the fieldbus coupler that accepts messages from the device and converts the messages for use by the node wherein the first protocol is configured to one of query the table and make a change to the table at a specified offset address in the table.