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UMCT(4) Device Drivers Manual UMCT(4)


umctMagic Control Technology USB-RS232 converter driver


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

device usb
device ucom
device umct

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



The umct driver provides support for USB to RS-232 converters based on the Magic Control Technology USB-232 design. These devices support most of the standard RS-232 features including baud rates ranging from 300 to 115200 bits per second. However, neither hardware nor software flow control seems to be supported.

Access to devices under this driver is via the ucom(4) framework and device nodes.


The umct driver supports the following adapters:

  • Belkin F5U109
  • Belkin F5U409
  • D-Link DU-H3SP USB BAY Hub
  • Magic Control Technology USB-232
  • Sitecom USB-232


for callin ports
corresponding callin initial-state and lock-state devices

for callout ports
corresponding callout initial-state and lock-state devices


tty(4), ucom(4), usb(4)


The umct driver appeared in FreeBSD 5.2. It is loosely based on the ubsa(4) driver by
Alexander Kabaev <> with documentation from
Wolfgang Grandeggar <>.


The umct driver was written by Scott Long <>.

April 26, 2017 Debian