Rs 485 example communication and how to use our libraries.
Arduino rs485 beispiel. The network has 120 ohm termination resistors at each end. More details about rs 485 modules here. In half duplex mode it has a data transfer rate of 2.
Rs485 is a physical connection standard for serial data transfer. Its possible to use an arduino as slave and with some restrictions also as master in modbus applications but a rs485 interface is needed. The example here shows two arduinos connected with low cost rs485 electronic bricks or breakout boards that use a max485 chip.
Next we will proceed to explain how this example works. Rs485 library for arduino enables sending and receiving data using the rs485 standard with rs485 shields like the mkr 485 shield. See rs485 example of two arduinos communicating over re 485 here.
Check out the detailed tutorial on rs 485 modbus serial communication with arduino as master. There is also a usb to rs485 module top right for use on pc s. How to install simplecomm libraries.
This library supports the maxim integrated max3157 and equivalent chipsets. See on rs 485 communication. Simplecomm libraries installed on your arduino ide.
Connect the other end of the power wire red wire from the arduino mega to the vcc power pin of the rs485 module picture 1 place a jumper between the de and re pins of the rs485 module picture 2 connect the other end of the tx wire green wire from the arduino mega to the di driver input pin of the rs485 module picture 3. See the example rs485 network diagram scroll down. For using rs 485 in arduino a module called 5v max485 ttl to rs485 which is based on maxim max485 ic is needed as it allows serial communication over long distance of 1200 meters and it is bidirectional.
Connect correctly the communication ports of rs 485 between both plcs.