The operation keyboard consists of 15 ppt keys, 10 numeric keys from 0 to 9. The "++" and "--" keys adjust the frequency and also produce emission output behavior. Short press the "++" or "--" key , add 1khz or subtract 1khz when outputting the frequency. Press and hold "++" or "--" for more than 1 second, and the scanning mode of continuous addition or continuous subtraction will appear To end the scan, just press the "++" "--" key or the "ok" key. The "ok" key is the output control key. Press it once to launch, and press it again to stop the launch. The launch behavior caused by "++" or "--" requires pressing "OK" twice to end the launch behavior. When this product has output transmission behavior, "" will appear in the upper right corner of the display, and the "C" key will end the transmission and return the frequency to zero There is a channel selection cycle button below the LCD screen, which cycles through the selections: "Channel 1 Output", "Channel 2 Output", and "Two Channels Output Simultaneously" by default at power-on "( )" key is replaced by a press-down mechanical rotary encoder. The scanning mode for continuous addition and continuous subtraction is easy to adjust. Cycle selection steps "1K", "10K", "100K", "1M", inherited All key operations of version V1.02 are available. Rotary encoder arrangement, counterclockwise rotation for decreasing operation, clockwise rotation for increasing operation, press down to replace the "()" step selection key of the keyboard Provide a signal source for the AC path of the device under test, analyze the frequency amplitude characteristics of the AC path, and pay attention to the impedance of the device under test Name:Signal Source Module Supply voltage: DC 4.5V-5.5V, note that the machine does not have a built-in voltage regulator unit, be sure not to over-voltage range power supply Supply current: 60mA Output bandwidth: 0.01mHz--150mHz Scanning output step: 1khz, 10khz, 100khz, 1mhz 4 stops Output impedance: 50 ohms Output waveform: square wave Output VPP: 2.6V Colour:As Shown Material:PCB Package Contents: 1x Signal Source Module 1x USB Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.