Frequency converters are used to control electric motors in many kinds of industrial applications. Since they control the electric motors that run the machines or processes, they must be strongly integrated with the rest of the automation system. If the wireless sensor and actuator networks are used as a part of the same automation system, it would be beneficial to have a direct connection between wireless sensor network and frequency converter instead of routing the information through several interfaces. To enable this, we built a software and hardware integration between frequency converter and wireless sensor network. Developed system was tested by performing several experiments in real industrial environment that consisted of sophisticated mobile machines. In the experiments, several frequency converters and sensor nodes were used in the same network. System performance and reliability was evaluated based on the experiment results, and some directions pointed for the future work.