MIKROE-2821

MIKROE-2821 Datasheet

PID MIKROE-2821

Part	Datasheet
MIKROE-2821	MIKROE-2821 (pdf)

PDF Datasheet Preview
RS485 3 click PID MIKROE-2821 Weight 25 g RS485 3 click uses SN65HVD31DR from Texas Instruments, a tri-state differential line driver and differential input line receiver. The click is intended to be used as UART to RS422/RS485 communication interface. It is suited for transmitting smaller blocks of data over long distances, using the four-wire bus, allowing for full-duplex communication. It can be used as a transceiver between UART interface and RS422/RS485 communication bus. RS485 3 click can be used for controlling various building automation systems, light controllers, sensors and many small embedded devices that can all share the same bus, which can stretch up to 254 nodes and up to 1200m in length. How does it work? The main feature of the RS422/RS485 interface is that the signals can be transmitted and received at distances up to 1200m by using the so-called twisted pairs - basically, the signal and its inverted copy are sent via the twisted pair wires. Because of the length of the twisted pair, it will unavoidably be exposed to the influence of the EMI. The interferences will appear in both wires of the twisted pair equally, but thanks to the opposite polarity of the signals the wires are carrying, the interferences will get canceled at the differential inputs of the SN65HVD31. This way, greater signal communication distances can be achieved than with the regular UART. RS422/RS485 only specifies electrical characteristics of the transmitter and the receiver. It does not specify or recommend any communications protocol, only the physical layer. The top layer communication protocol of choice can be used, such as the MODBUS or DMX protocols. To improve the signal stability, RS485 3 click is equipped with the TVS transient voltage suppression diodes used to protect the circuit from the static electricity discharges and other types of dangerous electrical discharges, that might occur. There are four onboard screw terminals RX+, Rx-, Tx+, Tx- for connecting RS422/RS485 twisted pair cable, along with two screw terminals GND for common ground connection. TX and RX pins should be used for connecting MCU UART interface. Two resistors R2 and R5 should be unsoldered if using more than two clicks on the RS422/RS485 bus. Specifications Type RS485 Transceiver between UART interface and RS422/RS485 communication bus. Controlling various building automation systems, light controllers, sensors and small embedded devices that can all share the same bus. modules SN65HVD31DR Driver and Receiver by Texas Instruments Key Features Full duplex serial communication over a distance up to 1200m, low power mode, receiver failsafe detection of the short circuit or disconnection , hot plug capability Interface UART Input Voltage 3.3V Click board size M x mm Pinout diagram This table shows how the pinout on RS485 3 click corresponds to the pinout on the mikroBUS socket the latter shown in the two middle columns . Notes Pin Notes UART transmit data UART receive data NC 5 MISO NC 6 MOSI Power supply 3.3V 7 3.3V Ground GND 8 Ground RS485 3 click electrical specifications Min Typ Max Unit Voltage at any terminal of the RS485 connectors ±5 12 V Differential load resistance 54 60 Onboard settings and indicators Label Name Default PWR Power LED Power LED indicates that the click is powered on Software support

PDF Datasheet Preview

RS485 3 click

PID MIKROE-2821

Weight 25 g

RS485 3 click uses SN65HVD31DR from Texas Instruments, a tri-state differential line driver and differential input line receiver. The click is intended to be used as UART to RS422/RS485 communication interface. It is suited for transmitting smaller blocks of data over long distances, using the four-wire bus, allowing for full-duplex communication.

It can be used as a transceiver between UART interface and RS422/RS485 communication bus. RS485 3 click can be used for controlling various building automation systems, light controllers, sensors and many small embedded devices that can all share the same bus, which can stretch up to 254 nodes and up to 1200m in length.

How does it work? The main feature of the RS422/RS485 interface is that the signals can be transmitted and received at distances up to 1200m by using the so-called twisted pairs - basically, the signal and its inverted copy are sent via the twisted pair wires. Because of the length of the twisted pair, it will unavoidably be exposed to the influence of the EMI. The interferences will appear in both wires of the twisted pair equally, but thanks to the opposite polarity of the signals the wires are carrying, the interferences will get canceled at the differential inputs of the SN65HVD31. This way, greater signal communication distances can be achieved than with the regular UART. RS422/RS485 only specifies electrical characteristics of the transmitter and the receiver. It does not specify or recommend any communications protocol, only the physical layer. The top layer communication protocol of choice can be used, such as the MODBUS or DMX protocols. To improve the signal stability, RS485 3 click is equipped with the TVS transient voltage suppression diodes used to protect the circuit from the static electricity discharges and other types of dangerous electrical discharges, that might occur. There are four onboard screw terminals RX+, Rx-, Tx+, Tx- for connecting RS422/RS485 twisted pair cable, along with two screw terminals GND for common ground connection.

TX and RX pins should be used for connecting MCU UART interface. Two resistors R2 and R5 should be unsoldered if using more than two clicks on the RS422/RS485 bus.

Specifications

Type

RS485

Transceiver between UART interface and RS422/RS485 communication bus. Controlling various building automation systems, light controllers, sensors and small embedded devices that can all share the same bus.
modules

SN65HVD31DR Driver and Receiver by Texas Instruments

Key Features

Full duplex serial communication over a distance up to 1200m, low power mode, receiver failsafe detection of the short circuit or disconnection , hot plug capability

Interface

UART

Input Voltage 3.3V

Click board size

M x mm

Pinout diagram

This table shows how the pinout on RS485 3 click corresponds to the pinout on the mikroBUS socket the latter shown in the two middle columns .

Notes Pin

Notes

UART transmit data

UART receive data

NC 5 MISO

NC 6 MOSI

Power supply 3.3V 7
3.3V

Ground GND 8

Ground

RS485 3 click electrical specifications

Min Typ Max Unit

Voltage at any terminal of the RS485 connectors ±5 12 V

Differential load resistance
54 60

Onboard settings and indicators

Label Name Default

PWR Power LED Power LED indicates that the click is powered on

Software support

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived MIKROE-2821 Datasheet file may be downloaded here without warranties.

Datasheet ID: MIKROE-2821 649446