How do I resolve serial USB power conflicts?

The USB-232, USB-232/2, USB-232/4, USB-485, and USB-485/2 are high- power bus-powered devices that require more than 100 mA during normal operation. Thus, they must be plugged into an externally powered hub that can deliver up to 500 mA per USB port. If the USB network does not have enough power to support the USB serial hardware, and a system dialog box informs you that there is not enough power for the device, reconnect the hardware to an externally powered hub.

The USB-485/4 is a self-powered device that requires external power. If the device is plugged into a USB port, and the device does not have power, it will not enumerate and the ports will not show in the Device Manager. To ensure proper port enumeration, always make sure the USB-485/4 has external power before connecting it to the USB network.