... In 1 RS485 Out Can control DVR, Matrix, controller Usb Hub (YK-UP501) 1Port RS232 + 2Ports RS485 to 1 ... OutputCan control DVR, Matrix, keyboard controller usb Hub, RS485 Serial Port Converter, RS485 HUB (YK-UP501) Product character1, 1pc RS232 ... cascade which will extend the input capability. usb Hub, RS485 Serial Port Converter, RS485 HUB (YK-UP501) Product specification Communication portInput: ...