You can close a hardware target by right-clicking on the hardware target in the Hardware window and selecting Close Target from the popup menu. You can also close the hardware target using a Tcl command. For instance, to close the xilinx_platformusb/USB21 target on the localhost server, use the following Tcl command:
Important: If the board is powered off or cable disconnected, Vivado IDE closes the hardware target in the Hardware Manager. Any Vivado operation in the main Vivado thread is also canceled. If the board is powered back on or the cable is reconnected, the Vivado IDE will attempt to re-open the hardware target in the Hardware Manager.