Abstract: A weld controller maintains an internal dynamic model of load impedance, which tracks normal impedance variations that occur as the weld tooling degrades. The weld controller contains a weld process monitor function that tests an estimated load impedance of a weld schedule presently under execution against an internal dynamic model and generates events when characteristics of the estimated load impedance of the present weld falls outside an operator definable band, indicating a problem with the workpiece presently being welded. The weld controller further includes the capability to accept a static model of the load impedance that is used as the reference impedance for the weld control and tooling. The weld controller also includes means to declare an event when characteristics of the dynamic model differ from the static model by an operator-defined amount.

Abstract: A communications network has an operator interface system for monitoring and controlling controllers utilizing any known control strategy. A common database is accessible across the communication network of controllers regardless of each controllers dissimilar data structure. The operator interface provides an apparatus for displaying, storing, and editing data obtained from the network. Data from each controller can be accessed by a master device based upon the controller's individual data structure and type through embedded objects resident in the master device's operating system and program. The data can then be displayed, edited, and stored by any data entry device that is capable of executing the master's program.