VX Series User's Manual-8-Key lock marking. When this icon appears at the maininterface, keys and knob are locked.Single loop modeList loop modeNo USB drive is inserted.USB drive is inserted.USB drive is inserted but its format is not supported.7 Operation InstructionVX4U has powerful functions and is easy to operate. All operations can be completedthrough a knob and a return key. The design of shortcut keys makes the operationsmore efficient.Generally, LED display can work normally, and the brightness is moderate afterfollowing four steps: Input Settings → Screen Settings → Brightness → OutputSettings. Other menus such as display control and advanced settings can help usersbetter control LED displays.See the following section for detailed operation.Step1: Input SettingsSet resolution of input signal. Resolution can be directly set and changed for inputinterfaces of DVI, HDMI and DP. Resolution of other sources can only be changedthrough front-end input devices.Input resolution can be set through two methods:I: Preset Resolution.Choose a proper resolution from the standard resolutions(@60Hz) preset on thecontroller. If there is no the resolution you want, please move on to method II:Customize Resolution�BrightnessOutput Settings25%Screen SettingsInput Settings1024x7681280x10241366x7681440x900Preset ResolutionCustom ResolutionII: Custom Resolution.Set Height, Width and Custom refresh rate, then select "Apply" and press the knobfor application. If not confirmed, custom resolution is invalid.