We will pull the enable pin high to put the MAX485 module in receiver mode. We will pull the enable pin high to put the MAX485 module in transmitter mode. Here again, we start with including the standard library for driving the LCD and declare the D8 pin of the Arduino Nano as an output pin which we will later use to declare the MAX485 Module as a transmitter or Receiver. They are often terminated with 8 pin RJ45 connectors at either end. We start with including the standard library for driving the LCD and declare the D8 pin of the Arduino Nano as an output pin which we will later use to declare the MAX485 Module as a transmitter or Receiver. Electronic data communications between elements will generally fall into two broad categories: single-ended and differential. Without termination resistors, reflections of fast driver edges can cause multiple data edges that can cause data corruption. The value of each termination resistor should be equal to the cable impedance (typically, 120 ohms for twisted pairs). There are many categories of Ethernet cables we can use like CAT-4, CAT-5, CAT-5E, CAT-6, CAT-6A, etc. In our tutorial, we are going to use CAT-6E cable which has 4 twisted pairs of 24AWG wires and can support up to 600MHz. It is terminated at both ends by an RJ45 connector.
Ideally, rs485 cable the two ends of the cable will have a termination resistor connected across the two wires and two powered resistors to bias the lines apart when the lines are not being driven. If you have any questions, leave them in the comment section below or use our forums and I will try my best answering them. At 1200m of transmission speed, you can use only 100kbps of transmission speed. It works on half-duplex communication to implement the function of converting the TTL level into RS-485 level which means it can either transmit or receive at any time, not both, it can achieve a maximum transmission rate of 2.5Mbps. MAX485 transceiver draws a supply current of between 120μA and 500μA under the unloaded or fully loaded conditions when the driver is disabled. This allows for basic error detection, in that if noise on the transmission line causes one bit to be received incorrectly, either received as a '0' when transmitted as a '1' or vice-versa, the error would be detected due to the count of '1' bits in the byte being odd when it is expected to be even, or vice-versa depending on the parity checking settings. An example of how a byte(0x3E) is transferred over the two lines of RS485 Communication.
EIA-485 (formerly RS-485 or RS485) is an OSI Model physical layer electrical specification of a two-wire, half-duplex, multipoint serial connection. Single master systems (many other communications schemes are available) offer a straight forward and simple means of avoiding "data collisions" in a typical 2-wire, half-duplex, multi-drop system. The master and slave could even exchange ascii QED-Forth operating system commands. The master can instruct a single slave to go into transmit mode, and then the master can put itself into receive mode, thereby allowing the master to retrieve data from the slave. The GROUND line serves as a common voltage reference for the master and slave. Chassis and signal grounds are connected together to the digital ground (GND) signal. SC, G or reference, the common signal reference ground used by the receiver to measure the A and B voltages. The USB-RS485-WE cable was designed to be used with Alliance Sensors Group LVDT Signal Conditioners and a laptop/computer.
The main reason behind using these Ethernet Cables over normal wires is that they provide much better protection against noise creeping in and distortion of the signal over high distances. They have Shielding Jacket over the insulation layer to protect against the Electromagnetic Interference and also each pair of wires is twisted together to prevent any current loop formation and thus much better protection against the noise. 5V power supply and the rated current is 300 μA. The flexibility and power of the 68HC11’s serial peripheral interface supports high speed communication between the 68HC11 and other synchronous serial devices. Utilizing a series of dedicated interface devices, it allows PCs and industrial controllers to communicate. The recommended arrangement of the wires is as a connected series of point-to-point nodes, a line or bus. RS485 meets the requirements for a truly multi-point communications network, and the standard specifies up to 32 drivers and 32 receivers on a single (2-wire) bus. In the most common multi-drop RS-485 protocol, one computer is designated as a "master" and the rest of the computers or devices on the serial bus are designated as "slaves". Now in the loop, we write a continuously increasing integer value on the Serial lines which is then transmitted to the other nano.