I want to analyze the efficiency of my data communication between slaves and master in the presence of interference. The protocol what I am using is modbus, with baud rate of 9600 , I am using 1000 ft cable. What I am struggling to do is, how to couple the noise into the cable in a way it is coupling in real time industrial environments. Also I dont know the voltage levels and frequencies of interference coming from motor and compressor and all which are common in industries. Any body knows the EMI level and frequencies of the interference common in industrial environments ?