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UCOM(4) 		     Kernel Interfaces Manual			 UCOM(4)

NAME
     ucom -- USB tty support

SYNOPSIS
     To compile this driver into the kernel, place the following line in your
     kernel configuration file:

	   device ucom

     Alternatively, to load the driver as a module at boot time, place the
     following line in loader.conf(5):

	   ucom_load="YES"

DESCRIPTION
     The  ucom	driver	attaches  to USB modems, serial ports, and other devices
     that need to look like a tty.  The ucom driver  shows  a  behavior  like  a
     tty(4).   This  means  that normal programs such as tip(1) or ppp(8) can be
     used to access the device.

SYSCTL VARIABLES
     The following variables are  available  as  both  sysctl(8)  variables  and
     loader(8) tunables:

     hw.usb.ucom.debug
	     Debug output level, where 0 is debugging disabled and larger values
	     increase debug message verbosity.	Default is 0.

     hw.usb.ucom.device_mode_console
	     When  set	to 1, the ucom driver will mark terminals as console de-
	     vices when operating in device mode.  Default is 1.

     hw.usb.ucom.pps_mode
	     Enables and configure PPS capture mode as described below.

Pulse Per Second (PPS) Timing Interface
     The ucom driver can capture PPS timing information as defined in RFC  2783.
     The API, accessed via ioctl(2), is available on the tty device.  To use the
     PPS capture feature with ntpd(8), symlink the tty device to /dev/pps0.

     The hw.usb.ucom.pps_mode sysctl configures the PPS capture mode.  It can be
     set  in  loader.conf(5) or sysctl.conf(5).  The following capture modes are
     available:
	 0     Capture disabled (default).
	 1     Capture pulses on the CTS line.
	 2     Capture pulses on the DCD line.

FILES
     /dev/ttyU*       for callin ports
     /dev/ttyU*.init
     /dev/ttyU*.lock  corresponding callin initial-state and lock-state devices

     /dev/cuaU*       for callout ports
     /dev/cuaU*.init
     /dev/cuaU*.lock  corresponding callout initial-state and lock-state devices

SEE ALSO
     cu(1), tty(4), uark(4), ubsa(4), ubser(4), uchcom(4), ucycom(4),  ufoma(4),
     uftdi(4),	uhso(4),  uipaq(4),  umcs(4),  umct(4),  umodem(4),  umoscom(4),
     uplcom(4), usb(4), uslcom(4), uvisor(4), uvscom(4), ttys(5)

HISTORY
     The ucom driver was adopted from NetBSD in March of 2002.	This manual page
     was adopted from NetBSD by Tom Rhodes <trhodes@FreeBSD.org> in April 2002.

BUGS
     Prior to FreeBSD 6.0 ucom created /dev/ucom? rather than the uniform device
     names created today.  Old scripts must be adjusted accordingly.

FreeBSD ports 15.1		  July 11, 2020 			 UCOM(4)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=ucom&sektion=4&manpath=FreeBSD+15.1-RELEASE+and+Ports>

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