Transmission speeds of 30-35 Mbps are supported for distances of up to 10 meters. RS485 cable length can be as long as 1.2 km, while RS232 only about 25 meters. Connect RS485 devices with 4 contacts. RS-485 is also used in building automation as the simple bus wiring and long cable length is ideal for joining remote devices. It requires minimal wiring and can share the wiring among several seats, reducing weight. After several frustrating days of trying different combinations of RS485 hats, different wiring connections, with and without termination resistors and ordering a USB RS485 adapter which would also fail to connect, we tried to install the Data logging WiFi adapter. Termination resistors also reduce electrical noise sensitivity due to the lower impedance. The RS485 employs a set of 120 Ohm termination resistors located at each end of the line. The value of each termination resistor should be equal to the cable characteristic impedance (typically, 120 ohms for twisted pairs).

In order to avoid signal reflections, a 120 Ohm termination resistance must be fitted on each end of the main cable. In order to avoid errors when many devices are connected, cables of the same colour should be used for all the connections to the terminals A and cables of the same colour should be used for all the connections to the terminals B of the various devices (e.g. white for A and blue for B). 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. In this implementation, software running on a PC monitors and controls a variety of subsystems. It is made up of hardware products (sensors, data loggers, and gateways, for example), software services (SenseCAP portal, mobile App, open dashboard), and an API for system and data management. An example is the VSAT NMS (Network Management System).

Serial communication also has a deterministic behaviour to avoid collisions of data packets, making it more reliable for a linkage system with many devices. A Modbus RS485 connects a Master device to one or more Slave devices. Most Modbus implementations use RS485 due to the allowance of longer distances, higher speeds and multiple devices on a single network. It is commonly implemented to control video surveillance systems and link security control panels to devices such as access control card readers. The cabling of the industrial communication systems (Modbus RS485) is different in some ways from the cabling used for power cabling and the electrician may experience some difficulties if he is not an expert in Modbus communication networks. Modbus is the world’s most popular automation protocol in the market. RS485 is used as the physical layer for many standards and proprietary automation protocols to implement control systems, most commonly Modbus. Offering you a complete choice of products which include rs-485 modbus cable, profinet cable, profibus cable, rs485 1 pair x 20 awg (0.5 sqmm) modbus armoured cable, rs485 1 pair x 17 awg (1.0 sqmm) modbus armoured cable and rs485 2 pair x 20awg (0.5 sqmm) modbus armoured cable. Control and monitoring systems: A single pair of rs485 signal cable can connect up to 32 devices, with a signal transmission distance of up to 1200m. Therefore, using rs485 cables is an ideal choice for industrial control and monitoring systems, especially those with large-scale and high dispersion.

RTS- signals are all employed as handshake control signals. The distances these signals are carried is greater due to differential signals. Due to this and it being able to transmit data over long distances, the RS485 is used commonly as a protocol for POS, industrial and telecom. The RS485 interface achieves superior transmission over greater distances and better data rate performance than the RS232 protocol. Rs485 cables not only vary in the structure of the core but also in the number of twisted pairs. RS485 at its core with 2 wires allows half-duplex data transmission. This ensures maximum protection for the inner core. The maximum number of devices that can be connected to a main cable is 32, including the Master. RS485 is made for serial communication with high speeds, support for long distances, and support for multiple devices (slaves). However, Arduino and Raspberry Pi hobbyists also use it for some of their projects when multiple peripherals need to be linked to the board. SenseCAP S2100 data logger can collect data from multiple sensors and transfer the data through the LoRaWAN network. These include MUXs, modems, RF up and down converters, and other network components. The recommended arrangement of the wires is as a connected series of point-to-point (multidropped) nodes, i.e. a line or bus, not a star, ring, or multiply connected network.