How to use CodeSys Modbus TCP slave and reach other connected Modbus RTU devices

Codesys makes programming simple and Straightforward.
But sometimes some application details takes awhile to find.
TLDR - 2 things to note:
1) To poll the TCP slave, use ID255 instead of 1
2) Connected RTU slave must be using 'Even' parity and '1 stop bit'

[@SaadShabbir1]

I cant call the function in my ladder. Is the license required to even use the functions?

[@demosthenes4276]

Thanks for your tutorial. Where do you set the slave address on 255?

[@chlow1627]

Hello, you don't have to set it. the codesys master is pre-configured to have 255 as the address. If you use anything else, it will not work

[@user-gf9di2uj9m]

do you have tutorial for modbus RTU as slave while controlled by the TCP master using converter?

[@chlow1627]

If you wish to use a USB-to-RS485 converter to make your PC into a slave, the only difference should be to choosing the respective COM-PORT.
Just open the windows device manager and then plug your device in. See which new com port appears
superuser.com/questions/1059447/how-to-check-com-ports-in-windows-10