Problem installing Insteon 2413U


(Revised post)
I am trying to connect an Insteon 2413U USB modem to a system running FreeBSD 10.0 release P9 (i386). It is a serial device with an integrated USB-to-serial converter from FTDI. I first tried to simply attach it to an available USB port. It seemed to error without giving anything useful so I loaded uftdi.ko (which also adds ucom.ko)
Feb 21 22:21:58 system4a devd: Executing 'kldload -n uftdi'
Feb 21 22:21:58 system4a kernel: uftdi0: <FT232R USB UART> on usbus3
It now appears to load successfully. The device desc usbconfig dump_device_desc is:
ugen3.10: <FT232R USB UART FTDI> at usbus3, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (90mA)

  bLength = 0x0012
  bDescriptorType = 0x0001
  bcdUSB = 0x0200
  bDeviceClass = 0x0000
  bDeviceSubClass = 0x0000
  bDeviceProtocol = 0x0000
  bMaxPacketSize0 = 0x0008
  idVendor = 0x0403
  idProduct = 0x6001
  bcdDevice = 0x0600
  iManufacturer = 0x0001  <FTDI>
  iProduct = 0x0002  <FT232R USB UART>
  iSerialNumber = 0x0003  <A704EOJV>
  bNumConfigurations = 0x0001
And the following devs are created:
< crw-rw----  1 uucp  dialer  0xac Feb 25 19:43 cuaU0
< crw-rw----  1 uucp  dialer  0xad Feb 25 19:43 cuaU0.init
< crw-rw----  1 uucp  dialer  0xb5 Feb 25 19:43 cuaU0.lock
< crw-------  1 root  wheel  0x99 Feb 25 19:43 ttyU0
< crw-------  1 root  wheel  0x9a Feb 25 19:43 ttyU0.init
< crw-------  1 root  wheel  0xa4 Feb 25 19:43 ttyU0.lock
< lrwxr-xr-x  1 root  wheel  10 Feb 25 19:43 ugen3.10@ -> usb/3.10.0
So my question is how to use it. Do I connect to the serial port, the tty port or something else?

Thanks in advance,