Power Supply: built-in rechargeable battery (charged via Type-C USB port), external Type-C USB-5V, external DC 15-30V, each way makes the generator work. Voltage Output: 0-10V, the precision is 0.01V, turn the encoder knob to adjust the output voltage, can be calibrated. Current Output: 0-22mA, the precision is 0.01mA, turn the encoder knob to adjust the output current, can be calibrated. Multiple Display Modes: just press the small button to switch display mode between voltage and current, you can also follow the instructions to switch 0-20mA or 0-50HZ display. The signal generator is designed to simulate 0-10V voltage signal and 0/4-20mA current signal for PLC and panel Debugging, Device Testing, Frequency Converter, Flow Valve, etc. It can display 4 different types of numbers, 0-10V voltage, 0-22mA current, 0-20mA, and 0-50HZ. It will play an important role in your electronics work. Power Supply 3 ways: built-in rechargeable battery, external Type-C USB-5V, external DC 15-30V, each way makes the generator work. How to judge whether the module unit is active or passive Common methods below: 1. Internal principle of the device, it is passive if \"I+\" is 24V+; it is active if \"I-\" is 24VG; 2. Use a multimeter to measure the voltage between \"I+\" and \"I-\", it is active if the value is 0V; it is passive if the value is 24V. Color: Black Material: plastic Size: 100x60x25mm Package Contents: 1 * Signal Generator Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture to differ slightly from the real one. The allowed measurement error is +/- 1-3 cm.