/dev/ttyU*
for callin ports
ucom4
Usb tty support
Usage
device ucom
In loader.conf(5): ucom_load="YES"
loader.conf(5) or sysctl.conf(5): hw.usb.ucom.debug hw.usb.ucom.device_mode_console hw.usb.ucom.pps_mode
Overview
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
ucomdriver will mark terminals as console devices 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*.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
Releases
61 releases since FreeBSD 4.7-RELEASE; the text changed 39 times.