Use Steps:1.connect To Power Supply;2.press Rotary Switch For 10second To Switch Normal Mode And Precise Mode;3.short Press Rotary Switch To Set Frequency And Change Value By Rotating Switch;4.press Rotary Switch For 2second To Set Duty Cycle; 5.keep Press For 5second To Lock Set Parameters; 6.test;7.press Button On/off To Turn On Or Off Pwm Output; 8.remove Power And Connect Load To Use Module. Xy-kpwm Signal Generator Is A Device That Provides Electrical Signals At A Variety Of Frequencies, Square Wave, And Output Levels.it Is Used As A Signal Source Or Excitation Source For Testing.widely Used In Production Practice And Technology. 1.with Outer Casing 2.lcd High Definition Display 3.support Uart 4.support Frequency Adjustment 5.support Duty Cycle Adjustment 6.high Precision Detection 7.support Power-down Memory Function 8.1-channel Pwm Output 9.dual Work Mode 10.knob Supports Lock Function To Avoid Misoperation 11.support Enable Output Parameters: 1.product Name: Xy-kpwm Pwm Signal Generator; 2.model: