#Modbus 2 Wire Wiring Details Full Duplex Mode
#Modbus 2 Wire Wiring Details Software Running On

Suggested communications wire is 18-22 AWG 2 core shielded cable. Connection is by means of a pluggable 3 way screw terminal. 2 Wire RS-485 Communications The RS-485 port communicates using the Modbus RTU or BACnet MSTP protocol.

RS485 is primarily used in multi-drop configurations that make use of its balanced differential interface. Data rates of 100Kbps can be achieved over distances of up to 1200 meters. Transmission speeds of 30-35 Mbps are supported for distances of up to 10 meters. The distances these signals are carried is greater due to differential signals.The RS485 interface achieves superior transmission over greater distances and better data rate performance than the RS232 protocol.

Modbus 2 Wire Wiring Details Software Running On

In order for this type of implementation to work correctly, properly wired RS485 connectors are required on the PC running the NMS application as well as all of the connected subsystems. These include MUXs, modems, RF up and down converters, and other network components. In this implementation, software running on a PC monitors and controls a variety of subsystems. An example is the VSAT NMS (Network Management System).

Modbus 2 Wire Wiring Details Full Duplex Mode

You will be able to determine the actual configuration based on the documentation that accompanied the device.The RS485 employs a set of 120 Ohm termination resistors located at each end of the line. In half-duplex mode, you can only transmit or receive data at any given time.The voltage range on the lines varies from -7 V to +12 V.There is no specific type of connector used to implement the RS485 protocol but in most scenarios, a DB9 connector or terminal block are employed.Specific RS485 connectors may have different pinouts. RS485 in full duplex mode 4 contacts are employed.Full-duplex mode is used when you need to be able to transmit and receive data at the same time. RS485 in half-duplex mode with 2 contacts The RS422 protocol has similarities with RS485 in that both conduct data transmission using differential signals.

RS485 Technical SpecificationsA description of the RS485 technical specifications is provided in the following table.