Everything You Need to Know Serial to Ethernet Converters Content Summary:
Serial to Ethernet converters provide the function of serial port to network, which can convert RS-232/485/422 serial port into TCP/IP network interface, and realize the bidirectional transparent data transmission between RS-232/485/422 serial ports and TCP/IP network interfaces. It enables the serial port devices to have the function of TCP/IP network interface immediately, connect the network for data communication, and greatly extend the communication distance of the serial port devices.
1. Principles of serial to Ethernet converters
Serial to Ethernet converters will connect a number of serial port devices, select and process serial data stream, and convert the existing RS232 interface data into the IP port data. The purpose is to send the traditional serial data to the popular IP channel, improve the utilization of existing devices, save the investment, and simplify wiring.
In terms of data processing, the serial to Ethernet converters complete the storage control of communication data between RS232 link and Ethernet. The system processes the serial port data streams from the serial port device and converts them into data frames that can be transmitted in Ethernet. The data frames from Ethernet are judged and converted into serial data sent to the responding serial port devices.
In terms of practical applications, the serial to Ethernet converters map the Ethernet interface of TCP/IP protocol to a standard serial port under the Windows operating system, and applications can send, receive, and control it just as it is a normal serial port. For example, a common computer has two serial ports, COM1 and COM2, through the serial to Ethernet converters, the serial ports above can be mapped to COM3, COM4, COM5 and so on.
2. Common technologies of serial to Ethernet converters
TCP Server & TCP Client
TCP Server Mode: The serial port device is equivalent to the TCP server, and other devices can be connected to serial to Ethernet converters as TCP clients and send the request to the serial port device through the serial to Ethernet converters.
TCP Client Mode:
A serial port device is also equivalent to a TCP client, which can be connected to a TCP server through serial to Ethernet converters.
It can be subdivided into UDP Server and UDP Client. The functions are analogous to TCP Server and TCP Client. Many serial to Ethernet converters will provide supporting parameter configuration software, which can generally find their own serial to Ethernet converters through the UDP protocol.
Http server & http client
Some serial to Ethernet converters provide web searching, parameter modification, or firmware updates by using the functionality of the http server. As an http client, a serial port device can connect to an http server through a serial to Ethernet converter.
The serial to Ethernet converter integrates DNS server, so it can get IP address dynamically. If the serial to Ethernet converter is connected to the server of the external network, such as Baidu, its IP address can be resolved through baidu.com. Generally, the outgoing DNS server should be set here.
Custom MAC Address
In the LAN, in order to remember the MAC address conveniently, some serial to Ethernet converters provide the function of customizing MAC address.
Modbus protocol conversion
Modbus protocol conversion is provided by serial to Ethernet converters. Generally, the following protocol interconversion can be provided:
ModbusTCP/IP and ModbusRTU；ModbusTCP/IP and ModbusASCII
ModbusUDP/IP and ModbusRTU；ModbusUDP/IP and ModbusASCII
ModbusRTUOverTCP/IP and Modbus RTU
ModbusRTUOverTCP/IP and ModbusASCII
ModbusASCIIOverTCP/IP and ModbusRTU
ModbusASCIIOverTCP/IP and ModbusASCII
In addition, watch dog, IO function, AT command, ADC sampling and other functions of serial to Ethernet converters are not described in detail.
3. Firmware updates of serial to Ethernet converters
Serial to Ethernet converters generally provide firmware updates in the following ways:
（1）Firmware updates through serial ports with supporting upper computer software generally.
（2） Firmware updates through TCP, UDP, FTP or TFTP protocols with supporting upper computer software generally.
（3）Firmware updates through http server. Common routers make firmware updates in this way.
4. Typical applications of serial to Ethernet converters
Serial to Ethernet converters (RS-232/485/422 standard) have the functions of virtual serial port driver access and automatically restore the connection after network interruption. Without adjusting devices and changing the configuration, users can make serial port devices connected to the Internet quickly, and manage the scattered serial devices and hosts centrally through the network. Serial to Ethernet converters are applicable to many modern automatic control systems and widely used in the field of intelligent transportation, intelligent manufacturing, environmental monitoring and petrochemical industry, etc.
Typical application: data center - out-of-band network management
What is "data center - out-of-band network management"?
The out-of-band network management system of data center consists of "console server, KVM server, intelligent power manager, out-of-band network management ", etc. The system has "emergency access channel, centralized access control, hierarchical authorization management" and other functions.
What kind of IT environment requires an out-of-band network management?
When the operation and maintenance personnel and IT equipment are not in the same physical location (this type of network environment includes telecom operators, BAT, cloud service enterprises, managed data centers, banks and their branches, etc.), the equipment failure cannot be solved through the network, and the operation and maintenance personnel can only go to the site.