Linking device in a process control system that allows the formation of a control loop having function blocks in a controller and in field devices

A linking device for interfacing with a plurality of field devices having function blocks communicatively coupled via a communication network that uses a first communication protocol and a controller, the linking device comprising:

• a stack communicatively coupled to the communication network that uses the first communication protocol to monitor substantially all communications on the communication network;
• a connection manager that uses the communication stack to coordinate communications on the communication network;
• a function block data manager that selectively processes at least some of the monitored communications to produce function block information that is associated with a function block implemented by at least one of the field devices;
• and
• a database manager that sends the function block information to the controller via a second communication protocol and receives another function block information associated with another function block implemented by the controller to be sent to said at least one of the field devices as part of a control loop different than the first communication protocol.

A field device interface system for use in a process control system having a controller and a user interface communicatively coupled together, a linking device having a processor therein coupled to the controller, and a plurality of field devices communicatively coupled to the linking device via a communication network that uses a first communication protocol, comprising:

• a computer readable memory in the linking device;
• a monitoring routine stored on the memory and adapted to be executed by the processor that monitors substantially all communications on the communication network;
• a communications processing routine stored on the memory and adapted to be executed by the processor that selectively processes at least some of the monitored communications to produce first function block information associated with a first function block implemented by one of the plurality of field devices;
• and
• a linking routine stored on the memory and adapted to be executed by the processor that sends the first function block information to a second function block implemented by the controller, wherein the first function block information is sent to the controller via a second communication protocol different than the first communication protocol wherein the first function block and the second function block are part of a control loop.