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These resistors, depicted in the figure below, are common circuits utilized to provide an external hard-wired failsafe for an RS485 network. The RS485 is also common in computers, PLCs, microcontrollers and intelligent sensors in scientific and technical applications. The aforementioned SenseCAP Sensor Hub at its stock has only 4 ports to connect RS485 sensors despite it being able to support up to 32 different RS485 sensors. Being a connector that is frequently used outdoors in severe environments, it is designed to be IP68-rated waterproof and dustproof. Ready-to-deploy Industrial-grade Outdoor Enclosure: IP66 waterproof rate outdoor enclosure with window and waterproof ventilation hole reserved for light and gas sensors, also comes with a customized mounting panel. There is a whole plethora of SenseCAP industrial-grade sensors, and this is just one of the many! Their main difference boils down to one having only support for RS485, while the other one supports RS232 and TTL as well. Similarly, RX refers to received signal lines, while TX refers to transmitted signals represented by triangles orientation. Making effective use of serial devices often involves converting between RS232, RS485, and USB signals. It has anti-ultraviolet and anti-rain features as well, making it suitable for long-term outdoor use.

Its rich features make it suitable for industrial control systems and similar applications. In the central chemical dosing and dispensing system of China's Hingsen Semiconductor, the configuration comprises central chemical storage tanks coupled with dispensing systems at each process point, controlled through valve boxes to regulate the supply of chemical reagents. Devices will be linked together via a bus configuration as shown in the picture above. RS485 is also commonly used for building automation as the simple wiring configuration and lengthy cable length are ideal for joining remote devices. Modbus is the world’s most popular automation protocol in the market. Most Modbus implementations use RS485 due to the allowance of longer distances, higher speeds and multiple devices on a single network. RS485 main advantages as compared to other serial communication are tolerance to electrical noise, lengthy cable runs, multiple slaves in one connection, and fast data transmission speed. RS-485 is designed for multi-point systems, where multiple drivers and receivers are connected and RS-232, on the other hand, is used for connecting only two devices. RS485 is designed for a multi-point system and it can connect up to 32 devices to a single transmitter.

This lowers the overall power demands of the system and extends the life of the solenoids by running them much cooler. In I&I applications, lightning strikes, power source fluctuations, inductive switching, and electrostatic discharge can cause damage to RS-485 transceivers by generating large transient voltages. The MIC5317 can provide up to 150 mA of downstream current which should be more than enough for the RP2040 and its companions. Place the two USB termination resistors (R303 and R304) close to their respective pins on the RP2040. In RS485 standard, data is transmitted via two wires twisted together also referred to as "Twisted Pair Cable". In this setup both the TX and RX share a single pair of wires, therefore it is limited to half-duplex data transmission as the data cannot be transmitted simultaneously to and fro each device. You can easily enjoy the advantages such as low power consumption and long transmission range, without affording the cost of changing the sensors you are using. Grounds between buildings may vary by a small voltage, but with very low impedance and hence the possibility of catastrophic currents - enough to melt signal cables, PCB traces, and transceiver devices.

On the other hand, it only supports USB-supported devices. Supports Third-party Data Loggers and IoT Platforms: Besides SenseCAP Data Logger, developers could connect to other data loggers that support MODBUS RS485 protocol and third-party IoT platforms. Modbus devices communicate using a Master-Slave technique where only one device (the Master) can initiate transactions (AKA queries). The use of high-quality TP cable prevents on the one hand side-to-side crosstalk between the transmitted signals while on the other hand reducing the sensitivity of the transmission device to induced noise signals. The protection network shown in Figure 9 demonstrates how the high breakdown voltage of the LTC2862-LTC2865 is used to advantage in a protection circuit that meets the highest defined IEC protection levels (Level 4) for surge, EFT and ESD, while extending the overvoltage fault tolerance to ±360V. The driver outputs use a progressive foldback current limit design to protect against overvoltage faults while allowing high current output drive. The capacitor values are a balance between current consumption and ESD suppression, with 470 pF being a nice middle ground. R1002 limits in-rush current when the MOSFET is switched so that neither the buffer or the MOSFET is damaged5.