A field bus is a two-way link between a programmable controller or operations monitor and an industrial device like a sensor, an electric motor, or a switch. It is a critical part of any automated industrial process - whether for factory automation (discrete processes like an assembly line) or process automation (continuous flow of materials being mixed, treated, or processed). PROFIBUS is a widely established program that allows for communication among and between controllers, fieldbuses, and actuator devices. This very concise introduction for industrial engineers, controls engineers, and manufacturing technicians covers the basics of field bus architecture and communication and the fundamentals of the PROFIBUS language protocol.