This book presents an application-level design method for a wireless sensor/actuator network (WSAN). The resulting WSAN system is used in the developing of a WDCS (Wireless Distributed Control System). The implementation of this wireless system involves the building of a WSN (Wireless Sensor Network) for sensing (data acquisition) and CAN (Controller Area Network) protocol fieldbus system for plant actuation. The embedded software of the CAN controller nodes is written in C language while the wireless sensor nodes of the WSN are programmed with software models written in nesC (network embedded system C) language. The sensor/actuator system is controlled by an intelligent digital control algorithm that involves a controller structure developed with velocity PID algorithm to satisfy the bumpless transfer and the anti-windup concepts needed for manual/auto operating aspect. This controller structure is developed as a fuzzy petri neural network (FPNN) learned by a learning algorithm based on back-propagation. The system is built experimentally in real-time and tested with a temperature control plant to verify its robustness.