Depending on the runtime, the configuration file is located in the following place: Location of the configuration file

All devices with a particular prefix available

[SysCom]

Linux.Devicefile=/dev/ttyUSB

;with this setting, ttyUSB0 will be available in CODESYS IDE as COM1, ttyUSB1 will be available in CODESYS IDE as COM2 and so on


Alternatively make a selection of devices available

[SysCom]

Linux.Devicefile.1=/dev/ttyUSB0

Linux.Devicefile.2=/dev/ttyAMA1

Linux.Devicefile.4=/dev/serial

;with this setting, ttyUSB0 will be available as COM1, ttyAMA1 as COM2, and /dev/serial as COM4