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USLCOM(4) Device Drivers Manual USLCOM(4)


uslcomSilicon Laboratories CP2101/CP2102/CP2103/CP2104/CP2105 based USB serial adapter


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

device usb
device ucom
device uslcom

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



The uslcom driver supports Silicon Laboratories CP2101/CP2102/CP2103/CP2104/CP2105 based USB serial adapters.

The datasheets for the CP2101/CP2102/CP2103 list the maximum supported baud rate as 921,600. Empirical testing has shown that the rates 1,228,800 and 1,843,200 also work, at least on some hardware, so the driver allows setting those rates.


The following devices should work with the uslcom driver:

  • AC-Services CAN, CIS-IBUS, IBUS and OBD interfaces
  • Aerocomm Radio
  • AKTACOM ACE-1001 cable
  • AMBER Wireless AMB2560
  • Arkham DS-101 Adapter
  • Argussoft ISP
  • Arygon Technologies Mifare RFID Reader
  • AVIT Research USB-TTL interface
  • B&G H3000 Data Cable
  • Balluff RFID reader
  • Baltech card reader
  • BEI USB VCP Sensor
  • Burnside Telecom Desktop Mobile
  • Crumb128 module
  • Clipsal 5000CT2, 5500PACA, 5500PCU, 560884, 5800PC, C5000CT2 and L51xx C-Bus Home Automation products
  • Commander 2 EDGE(GSM) Modem
  • Cygnal Fasttrax GPS and Debug adapter
  • DataApex MultiCOM USB to RS232 converter
  • Degree Controls USB adapter
  • DekTec DTA Plus VHF/UHF Booster
  • Dell DW700 GPS Receiver
  • Digianswer ZigBee/802.15.4 MAC
  • Dynastream ANT Development kits
  • Elan USBcount50, USBscope50, USBpulse100 and USBwave12
  • ELV USB-I2C interface
  • EMS C1007 HF RFID controller
  • Festo CPX-USB and CMSP interfaces
  • Gemalto Prox-PU/CU contactless card reader
  • Helicomm IP-Link 1220-DVM
  • IMS USB-RS422 adapter
  • Infinity GPS-MIC-1 Radio Monophone
  • INSYS Modem
  • IRZ SG-10 and MC35pu GSM/GPRS Modems
  • Jablotron PC-60B
  • Kamstrup M-Bus Master MultiPort 250D and Optical Eye/3 wire utility meter interfaces
  • Kyocera GPS
  • Link Instruments MS-019 and MS-028 Oscilloscope/Logic Analyzer/Pattern Generators
  • Lipowsky Baby-JTAG, Baby-LIN and HARP-1
  • MEI CashFlow SC and Series 2000 cash acceptors
  • MobiData GPRS USB Modems
  • MSD DashHawk
  • Multiplex RC adapter
  • Optris MSpro LT Thermometer
  • Owen AC4 USB-RS485 converter
  • Pirelli DP-L10 SIP phone
  • PLX CA-42 Phone cable
  • Pololu USB to Serial
  • Procyon AVS Mind Machine
  • Renesas RX-Stick for RX610
  • Siemens MC60 Cable
  • Silicon Laboratories generic CP2101/CP2102/CP2103/CP2104/CP2105 chips
  • Software Bisque Paramount ME
  • SPORTident BSM7-D USB
  • Suunto Sports Instrument
  • Syntech CipherLab USB Barcode Scanner
  • T-Com TC 300 SIP phone
  • Tams Master Easy Control
  • Telegesis ETRX2USB
  • Timewave HamLinkUSB
  • Tracient RFID Reader
  • Track Systems Traqmate
  • Vaisala USB Instrument cable
  • VStabi Controller
  • WAGO 750-923 USB Service Cable
  • WaveSense Jazz Blood Glucose Meter
  • WIENER Plein & Baus CML Data Logger, RCM Remote, and PL512 and MPOD PSUs
  • WMR RIGblaster Plug&Play and RIGtalk RT1
  • Zephyr Bioharness


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 uslcom device driver first appeared in OpenBSD 4.0. The first FreeBSD release to include it was FreeBSD 7.1.


The uslcom driver was written by Jonathan Gray <>.

December 9, 2019 Debian