SC-USB Optically Isolated USB Interface


The SC-USB allows Campbell Scientific dataloggers to communicate directly with computers that have a USB interface. The SC-USB is optically isolated, which helps eliminate noise pickup associated with PC power supplies and ground connections. The SC-USB can be used in place of an SC32B interface.

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Benefits and Features

  • Connects a PC to the CS I/O port of a datalogger
  • Helps protect components from electrical damage
  • High data transfer rates—up to 1 Mbps


SC-USB with 17648 cable that ships with the SC-USB

Detailed Description

The SC-USB Optically Isolated Interface is used to connect a datalogger's CS I/O port to a PC's USB port. Multiple devices can be connected to the SC-USB in parallel. Because the connection is optically isolated, the SC-USB interface can replace an SC32B/USB converter combination. Optical isolation helps eliminate noise pickup associated with PC power supplies and ground connections.

The SC-USB supports synchronous high speed data transfer for up to 1 Mbps (when supported by datalogger). Asynchronous communication is supported from 9600 to 115200 bps. The USB transfer rate is up to 12 Mbps.


Power Drawn from the PC and datalogger
Campbell Scientific Protocols Supported
  • Modem-Enable (ME)
  • Synchronous Device Communications protocol (SDC)
    SDC only works with datalogger operating systems created since October 2002 (CR10X 1.18 or higher, CR23X 1.15 or higher, etc.)
  • Concurrent-SDC (CSDC)
    CSDC only works with a PakBus dataloggers and the CR5000.
CS I/O Port Opto-isolated (signal isolation only) from the PC’s USB port to 47 Vac or dc
Operating Temperature Range -25° to +50°C
Cable Description Type-A male to type-B male
Cable Length 1.8 m (6 ft)
Dimensions 7.5 x 4 x 2 cm (3 x 1.6 x 0.8 in.)
Weight 85 g (3 oz)

Current Drain

Drawn from Datalogger
  • < 1 mA (standby)
  • < 20 mA (active)
Drawn from PC
  • < 18 mA (standby)
  • < 85 mA (active)

Communication Rates

Asynchronous 9600 bps to 115 kbps
Synchronous Up to 1 Mbps


USB version

The SC-USB uses USB version 1.1.

PC Operating System

The PC drivers support Windows 2000, XP, Vista, 7, 8, and 10 operating systems.

Datalogger Considerations

Compatible Contemporary Dataloggers

CR200(X) Series CR800/CR850 CR1000 CR3000 CR6 CR9000X

Compatible Retired Dataloggers

CR500 CR510 CR10 CR10X 21X CR23X CR9000 CR5000 CR7X


SC-USB Drivers v.2.10.00 (6.37 MB) 05-21-2014

The SC-USB's Software drivers for use with Windows Operating Systems. View Update History

SC-USB Firmware v.03 (8 KB) 09-25-2009

Current version of the SC-USB firmware. The SC-USB utility is used to update the firmware in the SC-USB.

View Update History

Frequently Asked Questions

Number of FAQs related to SC-USB: 4

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  1. The combination of the USB to serial (17394) and the SC32B is basically the same as the SC-USB. Both options enable communication between a computer and a datalogger with a CS I/O port.

  2. See the table for a detailed comparison:


     USB-serial  cable




     Useful for  Connecting

     PC USB port to  datalogger RS-  232 port

     Datalogger CS  I/O  port to laptop  COM  port

     Datalogger CS  I/O  port to laptop  COM  port

     Datalogger CS  I/O  port to PC  USB  port


     USB A male –  9-pin male

     9-pin male – 9-pin  female

     9-pin male – 9-pin  female

     USB B female –  9-pin male


     6 ft

     3 in.

     6 ft

     1.6 in.

     Power  Consumption


     Active <200 a="" --200--="">

     8 mA continuous

     Active <20 ma="" --20--="">

     Optically  Isolated





     Operating  Temperature


     -25° to +50°C

     -25° to +50°C

     -25° to +50°C

     Maximum Data  Transfer Rate

     1 Mbps USB

     115200 bps

    9600 bps

     1 Mbps USB

  3. Many of our more recent dataloggers have a Micro B USB port. Simply use a Type A to Micro B, male-to-male cable. Although any USB cable, with the correct connectors and drivers, should work, there is a better chance of success using a cable supplied by Campbell Scientific.

    For dataloggers with an RS-232 port, only a serial or USB to RS-232 cable (sometimes called a USB-to-serial-adapter cable) is needed. Although any USB to RS-232 cable should work with the appropriate drivers, there is a better chance of success using the USB to RS-232 cables sold by Campbell Scientific.

    There are several options for dataloggers that don’t have an RS-232 port but have a CSI/O port:

    1. Use the SC-USB connector/interface instead of the SC32B.
    2. Use the SC32B with a 17394, USB-to-9-pin male RS-232 cable.
    3. Use a user-supplied USB interface with the SC32B.

    For dataloggers with a CSI/O and RS-232 or USB port, it is not necessary to use the SC32B unless there is another device connected to the RS-232 port or there are concerns about low-level noise from a permanently connected, ac-powered computer.

  4. Communication through the datalogger’s CS I/O port requires an interface that converts the computer’s RS-232 voltage levels to the CMOS levels of the datalogger. Typically, that interface is an SC32B. The SC32B connects to the datalogger’s CS I/O port via an SC12 or serial cable and connects to a computer’s 9-pin serial port via a serial cable. When the computer does not have a serial port, a 9-pin serial-to-USB cable, such as pn 17394, can be used with the SC32B. Alternatively, instead of the SC32B, use the SC-USB.