Eztronics Corp 5 PCS UART to RS485 Converter RS485 to TTL Module Precise Module The module is fully considered mine design, long-distance transmission signal 485 in the wild, the module "Connected to the ground" terminal is connected to the earth, can play a very good anti-jamming and anti-lightning effect, more secure; it can not connect with the ground when the indoor short-distance transmission. Using the standard 2.54 pitch design, easy secondary development. Has a 120 ohm termination resistors, shorted R0to enable the termination resistor. Support multi-machine communication, allowing access at up to 128 devices on the bus The module can be hot swapped, the signal does not appear dead phenomenon. A large area of copper to prevent interference.