Connect PLC and Arduino for color sensor

We are working on an automation project for college. We want to use a color sensor to recognise one color and eliminate others. We have Siemens s7-300 PLC and it uses MPI for communication. We haven't purchased a color sensor and Arduino board yet. Is it possible to interface the same or give the output from Arduino to PLC as input? I think this model of PLC does not have an ethernet port. I am not sure. Any help writing code for the same will be helpful as we are completely new to this.