The STB-3 is a multi-signal generator demo board designed to showcase the advanced features of Siglent oscilloscopes. It can generate a variety of common waveforms (sine, square, AM signals), special signals (PWM, glitch, slope, runt, and pseudo-noise), and serial protocol signals (I2C, SPI, UART, LIN, CAN). These signals are ideal for demonstrating advanced oscilloscope functions such as triggering, decoding, digital-phosphor display, and more. The board also supports pass/fail testing and MSO (Mixed Signal Oscilloscope) demonstrations, making it a versatile tool for both learning and testing.