The Station Audio Control (SAC) is specifically developed for monitoring and surveillance of PA speaker networks, for example on railway station facilities. It enables measuring of audio levels from both the line inputs and amplifier outputs of amplifiers. Deviations from preset values are signaled and reported, e.g. to a server via an SNMP trap.

Additionally, impedances of speaker networks are checked as to whether these are still within the permitted margin. A maximum of 4 speaker networks, plus associated amplifier inputs & outputs, can be connected. The impedance measurement ranges from 2O to 5000O.