The module is fully consider the 485 mine design and anti-jamming design, in the field for long distance transmission, it will block the "earthed" side to earth, can play the role of a good anti-jamming and lightning protection, make 485 more secure; you can not connect with the earth indoor short-distance transmission. Using a standard 2.54 pitch design for easy secondary development. Having a 120 ohm termination resistors that shorted R0 to enable matching resistor, when long-distance transmission is recommended shorting. Support multi-machine communication, allowing access at up to 128 devices on the bus. The module can be hot-swappable, hot-swap does not appears dead bolt phenomenon that occur to other 485 chips. A large area of copper to prevent signal interference.