... layers Processing 2 Fully Configurable Inputs Seamless Switcher, with Preview monitor, USB input, LED display Video Processor(VSP 1121) 1 3 ... the preview output,use can send each input to preview monitor,and after confirm take the input to program output , ... managerd by using the RGBlink software. Seamless Switcher, with Preview monitor, USB input, LED display Video Processor(VSP 1121)Demo diagram ...