This paper describes the development of a simulated production demonstrator, used in the development of the openMOS plug-and-produce architecture. Primarily designed to allow synthetic testing of plug-and-produce technologies, the intention is to simulate real production hardware, such that there is no perceivable difference to the production controller. Communication with the main production controller is achieved via network, using individual embedded computers to act as PLC based 'device adaptors'. Each production device is also either simulated using the same embedded computer, or externally on a more powerful computer, with simulation specific information (such as material flow) transferred using ROS. Testing has proven the concept to work well, allowing for a larger demonstration of the openMOS project but at a fraction of the cost.