Campbell Scientific SC-USB USB to CS I/O Optically Isolated Interface - Manual (Page 29)

SC-USB USB to CS I/O Opto-isolated Interface
As shown below the com port number is shown at the end of the description.
In some cases a PC program may not offer the SC-USB COM port in its
selection list of available COM ports. Recent versions of Campbell Scientific
packages allow you to manually type the COM port into the selection window
to overcome this.
Older software may also limit you only up to COM4. In that case you would
need to free lower com port numbers (by deinstalling an unused COM port)
and move the assignment of the SC-USB. To do this right click on the
SC-USB in the device manager screen (as shown above) and select properties.
Then select Port Settings and then the Advanced button. In the next screen you
have the option to change the COM port number to another free number. ‘OK’
any change you make and close the Device Manager screen before reopening it
to confirm the change (it does not automatically refresh this change).
The Baud rate settings in the driver/properties setting have no
influence on the operation of the SC-USB. The speed of
communication to the datalogger is normally determined
automatically by the SC-USB, although it can be set in other
ways. See the sections below. NOTE
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