Disclosed herein are techniques for virtualizing the I/O of control modules that are to be implemented by a process controller in the runtime environment of a process plant. A configuration application identifies references to the I/O objects utilized by the control modules. In response, the configuration application generates virtual device signal tags (DSTs) to mimic the performance of the identified I/O objects. To facilitate testing and/or verification of the control module, e.g., during the commissioning of a back-end environment, the configuration application instantiates a virtual controller in a simulation environment. To generate the virtual controller, the configuration application replaces any references to the I/O objects with references to respective, generated virtual DSTs. Thus, by using the virtual DSTs as a proxy for the I/O to the field devices, the control module and/or controller may be tested prior to the field devices without the field environment being fully commissioned.