The instrument USES direct digital frequency synthesizer (DDS) technology to provide stable, accurate, pure and low-distortion signals.Surface mount technology can improve anti - interference and service life.Function of 100M frequency meter: it can measure frequency, period, pulse width and duty ratio. The frequencies that work are 100MHz and Min. Frequency behavior: 0.01 Hz. Rich keyboard shortcuts and graphical user interface simplify each operation, easy to operate.The display interface adopts 2.4-inch TFT color LCD, which makes the operation more intuitive and convenient.Various modulation types: AM, FM, PM, ASK, FSK and PSK modulation. Counter function: there are 2 coupling measurement modes, including DC coupling and AC coupling. This design can solve the inaccurate problem of ac coupling.Output short circuit protection,when the load short circuit, all channels can work for more than 60 seconds. VCO function (voltage control output): it can be realized by external input signal: voltage control frequency, voltage control amplitude, voltage control offset, voltage control duty ratio and PWM modulation. Scanning function: four properties of the scannable signal, including frequency, amplitude, offset and duty cycle; It has two kinds of Linear and Logarithm scanning type; Scanning time: 0.01S-9999.99S; Up, down and round trip scanning directions.