A flexible graphical extension engine having a function block engine combined with extensions in communications with a wall module bus to make it possible to provide fixed function, configurable function and programmable function devices which implement additional function block behavior, and provide an automated configuration approach for generating configuration files for a programmable wall module. In other words, the engine not only depends on fixed inputs and outputs (I/O's) and fixed features in a control solution, but also may allow for flexible blocks and the ability to change an interface on the fly (i.e., during operation).