The FLEXUS FX100 was selected as the hardware platform for the loudspeaker and signal generator tests. It is able to test loudspeaker lines within a few 100 ms. Also, thanks to its versatile interfaces, it can be easily integrated into existing control systems. In collaboration with the team around project leader Johann Rehlinger from Siemens Augsburg, a simple and robust TCP/IP-based interface was defined for communication between the FX100 software and the Siemens PLC (Programmable Logic Controller). The PLC acts as the master, triggers measurements on the FX100 and receives PASS/FAIL results as well as detailed measurement results. The outcome of all measurements are collected, evaluated and summarized into a daily status report for the service technician in charge.
The FX100 measures the impedance response of each loudspeaker line, and compares the result with a previously-gathered reference. The limits for a PASS/FAIL decision are chosen, so that a single defective loudspeaker within a line is reliably detected. The Siemens PLC switches each single loudspeaker line to one of four control centers, each hosting an FX100 device, and then triggers the measurements.
Since there was only a small time window available for the implementation in the nuclear power plant, the complete system was built up at the Siemens site in Augsburg for an extensive test phase. After passing all tests and accreditation by the legal regulator TÜV, the system was integrated and activated in the nuclear power plant in two short stages. NTi Audio is proud to have contributed to increased safety in the Gundremmingen Nuclear Power Plant.