Error handling

All access to the drive/motion control is via Function Blocks. Internally these Function Blocks provide basic error checking on the input data. Exactly, how this is done is implementation dependent. For instance, if MaxVelocity is set to 6000, and the Velocity input to a Function Block is set to 10,000, a basic error report is generated. In the case where an intelligent drive is coupled via a network to the system, the MaxVelocity parameter is probably stored on the drive. The Function Block has to take care that it handles the error generated by the drive internally. With another implementation, the MaxVelocity value could be stored locally. In this case the Function Block will generate the error locally.

Both centralized and decentralized error handling methods are possible when using the motion control Function Blocks.

Centralized error handling is used to simplify programming of the Function Block. Error-reaction is the same inde-pendent of the instance in which the error has occurred.

Function Blocks with centralized error handling

Decentralized error handling gives the possibility of different reactions depending on the Function Block in which an error occurred.

Function Blocks with decentralized error handling