Digital Tube: Handheld digital signal generator includes a 4-digit high-definition tube, the screen brightness is uniform and adjustable (1-8 brightness). Usage: In the signal generator's normal operation screen simulation, save a voltage and current value, click the encoder to save, after releasing the OK button, the screen will display, meaning the saving is successful. Power Supply: The voltage signal generator has an external DC 15-30V power supply, which can share the 24V power supply from PLC and other equipment. Three Power Supply Methods: There is an external power supply, DC5V micro USB, built-in lithium battery (only if you choose type 1 can you build in the lithium battery in charging mode). Features: Restart directly and display the saved value, no need to adjust the parameters every time you turn on the signal generator, which is very convenient.