*2.2. CMS Hardware*

The central component of the remote-side CMS hardware uses Adlink's USB-2405, with which each channel can be connected to an accelerometer or a microphone. The USB-2405 is a 24-bit USB interface for dynamic signal data acquisition. The USB-2405 has a USB-interface power supply and BNC connector; there are four analogue input channels, and each channel provides up to 128 kS/s of simultaneous sampling. The USB-2405 also features selectable AC or DC coupled inputs and a built-in high-precision 2 mA excitation current measurement integrated electronic piezoelectric (IEPE) sensor. Each channel can be connected to an accelerometer or microphone for measuring vibrations or noises. In the measurement system, each channel was connected to a PCB 601A01 accelerometers with a sensitivity of 100 mV/g and a frequency band range of 0.27 to 10,000 Hz.

Relatedly, the CMS can be divided into vibration and noise detection subsystems, and each subsystem has its effective fault detection and diagnostic methods. The integration of technologies inspecting the wind turbine near the accelerometer or microphone enables the operation status monitoring functions and the preliminary remote-side fault-diagnosis functions. However, it is difficult to derive effective rules that can be used for such fault diagnosis on the remote side. This is discussed in the next subsection.
