what is the role of ic4n35 in pcb mastermodule used in serial communication?

Question

we want to develop modbus master module so we need to integrate each and every ic.as there are eleven ics.ic4n35 is one of them

Answer 1

the 4n35 is an optocoupler used to isolate the outside world from the device (in this case the serial port). below is a link to the data sheet.