The MODBUS RTU/ASCII protocols are communicated over a RS485 connection. This is usually connects via a serial RS485-to-USB converter to the computer.

You need to install the corresponding serial driver for the chipset of this converter on your PC, otherwise no serial port for the device is created by your operating system on connecting the machine. Most common drivers are

Watch out! The FTDI driver is preinstalled on virtually all Linux distributions as well as all OS X versions supported by Artisan. Installing an additional FTDI driver on those operating system might lead to instabilities!

Serial Driver Cheat Sheet

.. table to be extended and corrected as we receive new information from you ..

Machine Driver Remarks
Ambex FTDI  
Arc CP210x CH34x on newer Models
Besca FTDI CH34x on some older machines
BellaTW PL2303 CH34x on some machines
Bideli CH34x  
BlueKing CP210x on some older machines FTDI, on others CH34x
BC Roasters CP210x on some older machines FTDI, on others CH34x
Coffeed CH34x  
Coffee Tech FTDI  
Coffee Machines Sale CH34x  
Dätgen CH34x  
Dongyi CP210x FTDI on some older machines
Easyster FTDI  
Garanti CP210x  
Golden Roasters CH34x  
Has Garanti FTDI  
HB CP210x  
Kaleido CH34x  
KapoK CH34x  
NOR FTDI CH34x (on N Series V.4 old machines)
Nordic PL2303  
Plugin Roast CH34x  
Phoenix CH34x  
Proaster FTDI  
Roastmax FTDI  
Rolltech CH34x  
San Franciscan FTDI  
Santoker CP210x FTDI on some machines
Sedona CP210x  
Toper CP210x CH34x on some machines
Yoshan CP210x