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In automobiles, both RS232 and RS485 serial ports are widely used in communication between various devices and systems.
The RS232 interface is mainly used in cars to connect GPS receivers, handheld oscilloscopes and other peripherals. Due to the arbitrary location of the GPS receiver in the car, there is no unified standard for the data communication protocol between the car power system and the GPS receiver. At this time, the RS232 serial port is used to connect various devices to the car internal local area network (CAN-BUS) to achieve data sharing and coordination, which is convenient for the positioning, diagnosis and management of the car.
At the same time, the car will generate a lot of real-time data during operation, such as vehicle mileage, engine speed, fuel consumption, etc., which CAN be transmitted to the on-board computer through CAN-Bus. However, if you need to communicate the on-board computer with external devices, you need to use the RS485 serial port.
In contrast, the RS485 serial port has faster data transmission speed, longer transmission distance, and multi-station communication capability, so it is more suitable for long-distance communication and multi-point communication in the car. For example, in the process of automotive intelligent networking, the vehicle terminal needs to interact with multiple sensors, actuators and other devices for data, then data transmission and communication can be carried out through the RS485 serial port.
RS232 and RS485 are common serial communication interfaces, they have some differences in physical structure, communication distance and anti-interference.
Physical structure: The RS232 interface appears in the form of 9 pins (DB-9) or 25 pins (DB-25), and there are two groups of RS232 interfaces on general personal computers, respectively called COM1 and COM2. The RS485 interface does not have a specific physical shape, and it is an interface used according to the actual situation of the project.
Communication distance: RS232 transmission distance is limited, the maximum transmission distance standard value is 15 meters, and only point-to-point communication, the maximum transmission rate is 20kB/s. The standard value of the maximum transmission distance of the RS485 interface is 4000 feet, in fact, it can reach 3000 meters, and the transmission rate is up to 10Mbps.
Anti-interference and multi-station capability: the maximum data transmission rate of RS-485 is 10Mbps, which uses a combination of balanced drivers and differential receivers, and has enhanced common mode dry resistance, that is, good anti-noise interference. In addition, the RS-485 interface allows the connection of up to 128 transceivers on the bus, while the RS232 interface only allows the connection of 1 transceiver on the bus.
In automobiles, both RS232 and RS485 serial ports are widely used in communication between various devices and systems.
The RS232 interface is mainly used in cars to connect GPS receivers, handheld oscilloscopes and other peripherals. Due to the arbitrary location of the GPS receiver in the car, there is no unified standard for the data communication protocol between the car power system and the GPS receiver. At this time, the RS232 serial port is used to connect various devices to the car internal local area network (CAN-BUS) to achieve data sharing and coordination, which is convenient for the positioning, diagnosis and management of the car.
At the same time, the car will generate a lot of real-time data during operation, such as vehicle mileage, engine speed, fuel consumption, etc., which CAN be transmitted to the on-board computer through CAN-Bus. However, if you need to communicate the on-board computer with external devices, you need to use the RS485 serial port.
In contrast, the RS485 serial port has faster data transmission speed, longer transmission distance, and multi-station communication capability, so it is more suitable for long-distance communication and multi-point communication in the car. For example, in the process of automotive intelligent networking, the vehicle terminal needs to interact with multiple sensors, actuators and other devices for data, then data transmission and communication can be carried out through the RS485 serial port.
RS232 and RS485 are common serial communication interfaces, they have some differences in physical structure, communication distance and anti-interference.
Physical structure: The RS232 interface appears in the form of 9 pins (DB-9) or 25 pins (DB-25), and there are two groups of RS232 interfaces on general personal computers, respectively called COM1 and COM2. The RS485 interface does not have a specific physical shape, and it is an interface used according to the actual situation of the project.
Communication distance: RS232 transmission distance is limited, the maximum transmission distance standard value is 15 meters, and only point-to-point communication, the maximum transmission rate is 20kB/s. The standard value of the maximum transmission distance of the RS485 interface is 4000 feet, in fact, it can reach 3000 meters, and the transmission rate is up to 10Mbps.
Anti-interference and multi-station capability: the maximum data transmission rate of RS-485 is 10Mbps, which uses a combination of balanced drivers and differential receivers, and has enhanced common mode dry resistance, that is, good anti-noise interference. In addition, the RS-485 interface allows the connection of up to 128 transceivers on the bus, while the RS232 interface only allows the connection of 1 transceiver on the bus.
