Digital tube: Handheld digital signal generator features a 4-digit high-definition display with uniform and adjustable screen brightness (levels 1-8). Use: During normal operation, the signal generator simulates the screen and saves voltage and current values. Click the encoder to save; after releasing the OK button, the screen displays confirmation, indicating successful saving. Power supply: The voltage signal generator supports an external DC 15-30V power supply, compatible with the 24V power supply of PLCs and other equipment. It offers three power options: external power supply, DC5V micro USB, and built-in lithium battery (only available in model type 1 with battery charging capability). Features: Automatically restarts and displays the last saved value, eliminating the need to readjust parameters each time the signal generator is powered on, ensuring convenient operation.