Serial communication includes physical layer (physical link transmission, serial line), data link layer (framing,Start bit, data bit, check bit and end bit) and application layer (the packaging of application data is made by the serial port programming itself).。
The relationship between serial port and Ethernet: There are two communication modes, and the implementation principles and application scenarios are different.
Serial port to Ethernet port:
Serial to Ethernet is not a simple change of transmission media, but a protocol conversion from serial to TCP/IP.The key technologies include: the working mode of TCP/IP, serial port framing technology, 9-bit technology.
Generally speaking, serial port is UART, which actually only defines the specification of data link layer, that is, start bit, data bit and stop bit.But in different physical layers, it can be divided into TTL serial port, RS232 serial port, RS485 serial port and so on.
Because the serial port protocol itself does not have a network layer and a transport layer, the serial port is converted to an Ethernet port,In fact, the data of serial port is regarded as the application layer data of TCP/IP, which is encapsulated and transmitted by TCP/IP.The application layer data of TCP/IP is the real valid data that TCP/IP wants to transmit.For example, what the user receives and sends through the recv () and send () functions of the socket is actually application layer data.In this way, users can use recv () and send () functions to send and receive serial data through the serial port to TCP/IP.
RS232 to Ethernet converter are typically not part of the network layer, but are physical or data link layer devices.
Serial port is a communication interface used to transmit data serially, which is usually used to connect computers and external devices.Uch as printers, modems, etc. Serial ports transmit data by sending and receiving successive sequences of bits.
The Network layer is the layer in a computer network that is responsible for the transfer of packets from a source host to a destination host.It handles functions such as network addressing, routing, and packet fragmentation.
While the RS232 to Ethernet converter is typically used to connect serial devices to a network, it does not belong to the network layer itself.But convert that serial port interface into a network interface so that the serial port device can communicate through the network.RS232 to Ethernet converter works in the lower physical layer or data link layer, responsible for serial data forwarding and processing.
RS232 to Ethernet converter is a network device.
The RS232 to Ethernet converter is a device that is connected through a network.Used to connect serial devices (such as serial printers, serial terminals, serial sensors, etc.) To a LAN or Wan.It realizes the remote access and management of serial devices by encapsulating serial data into network packets and transmitting them through the network.
The RS232 to Ethernet converter usually has a network interface (such as an Ethernet interface) and a serial interface (such as an RS-232 or RS-485 interface).Through these two interfaces, the connection between the serial device and the network is realized.It can forward serial port data to other devices in the network or to a remote computer,And forward the data received from the network to the serial device.
RS232 to Ethernet converter is widely used in industrial automation, remote monitoring, Internet of things and other fields.It provides a convenient and remote way to manage and access serial devices, and simplifies the maintenance and management process of devices.
Yes, the RS232 to Ethernet converter can usually be used as a gateway.
A gateway is a device that connects two different networks and communicates between them by forwarding packets.The RS232 to Ethernet converter can act as a gateway to connect serial devices to a local or wide area network.So that the serial devices can be remotely accessed and managed through the network.
Usually, the RS232 to Ethernet converter provides a network interface and a serial interface, and encapsulates the serial data into a network data packet,And transmit to the remote equipment through the network, realize the remote access of the serial port equipment.At the same time, it can also parse the data packet received from the network into serial data and send it to the serial device through the serial port.
Therefore, RS232 to Ethernet converter can be regarded as a bridge between serial devices and the network, playing the role of a gateway.So that the serial devices can be easily managed and controlled through the network.
There are some differences between RS232 to Ethernet converter and PLC gateway, although they have similar functions in some aspects.
1. Function positioning: RS232 to Ethernet converter is mainly used to connect serial devices to the network.So that serial devices can be remotely managed and accessed through the network. It encapsulates serial port data into network data packets for transmission.The PLC gateway is more focused on connecting PLCs (programmable logic controllers) of different protocols to the upper system (such as the upper computer or cloud platform).Realize data exchange and communication.
2.Supported device types: RS232 to Ethernet converter usually supports various serial devices, such as serial printer, modem, etc.The PLC gateway is designed to communicate with the PLC and supports a variety of PLC devices and communication protocols, such as Modbus, Profibus, EtherNet/IP, etc.
3. Communication protocol: RS232 to Ethernet converter usually supports common network protocols, such as TCP/IP, HTTP, SSH, etc.O as to remotely manage and access the serial port device.The PLC gateway needs to support specific communication protocols and data formats to exchange data with the PLC.These protocols are usually determined according to the specifications of the PLC manufacturer.
4. Data processing capabilities: PLC gateways usually have more powerful data processing and conversion capabilities.It can analyze, process and convert the data of PLC equipment to meet the needs of the upper system.The RS232 to Ethernet converter is usually only responsible for data transmission and forwarding, and does not process data.
Although the RS232 to Ethernet converter and the PLC gateway overlap in some functions, their design and application scenarios are different.The choice of which equipment to use should be based on the specific needs and type of equipment.
