I did a quick research about the MODBUS Simulator and I found this site: Modbus Poll Quick start. According to it, you can use serial (RS485) or Ethernet to establish a connection with the device. The Edison doesn’t have any of these interfaces. Since you are using the Arduino Expansion Board, my suggestion is to use an Arduino shield to add the Ethernet or RS485 interface. However, I don't know if the MODBUS Simulator works with Edison, you should test it by yourself.