Industrial networks rely on standard real-time communication protocols like ProfiNet. These protocols are used for cyclic data exchange between IO devices and controllers. Since continuous monitoring of IO devices is important, a large number of data packets can be observed in such field networks between the IO devices and controllers. Each IO device cyclically reports its data or internal state to a controller at a predefined frequency. However, the reported data of most IO devices are not changing all the time, and thus the same bytes are transmitted multiple times. The majority of data packets is only used for checking the availability of such devices. In this paper, we consider an industrial environment where IO devices are located in an industrial site while controllers are running remotely (e.g., a software PLC in a private or edge cloud), and there is a radio link (e.g., 5G radio) between the two sides. We propose an in-network traffic reduction method that filters out the unnecessary data traffic at the two ends of the radio link, detects failure of devices and the radio link fast, and does not require any modification in the IO devices and controllers. Our solution is based on the cooperation of two P4-programmable networking elements deployed at the two sides of the radio link. Our preliminary measurements with P4-programmable hardware switches and emulated ProfiNet devices show that the method can significantly reduce the load on the radio link, while it could seamlessly be deployed in existing industrial environments.