1.The definition of serial device networking server
Serial device networking server is, as the name implies, an interface transformation device that connects a serial port to a network, since the serial port generally includes RS-232/485/422, and the network protocol also refers to the TCP/IP protocol, the serial device networking server can also be called to convert the RS-232/485/422 data format into TCP/IP data format or TCP/IP data format is converted into a communication interface converter in the form of RS-232/485/422 data.
2.The origin of serial device networking server
For serial device networking server, two key words are serial port and network. The network is divided into two types: internal network and external network. At present, the internal network generally refers to Ethernet, and the external network refers to the Internet, which is an effective means for communication on a global scale. Before the network becomes popular, data exchange between the device and the computer is generally implemented through a simple RS232; RS485 (up to 1000 meters) can also be used if long distance transmission is required.
With the development of the network and modern information technology, several requirements for equipment are gradually raised:
Some applications require remote monitoring of devices distributed around the world.
In applications such as computer room monitoring, self-service banking system communication, office building automation control system, etc., it already has complete network wiring, whether it can use these existing network facilities to achieve device communication.
For RS232 interface, a serial port of a PC can only be connected to a serial port device. If multiple devices need to be connected, the original serial port solution will not be easy to expand, but the network does not have this problem.
Due to above reasons, it is necessary to connect the device to the network. However, thousands of original serial devices have already existed, and the large-scale transformation of these devices is obviously not a one-step process, transforming the large number of devices can not be accomplished in an action, therefore, as a temporary solution-the serial port networking server that converts the serial port into a network port has emerged.
3.The application areas of serial port networking server
Serial device networking server is currently used in: access control attendance systems, POS systems, food sales systems, building automation systems, power monitoring, self-service banking systems, telecommunication room monitoring.
4.The usage ways of serial device networking server
When you get a serial device networking server: 1. Wiring: first, connect the serial port of the serial device networking server to the serial port of the device, connect the RJ45 interface of the serial device networking server and the router (or connect directly to the PC, generally it needs to cross the network cable), and then power on the serial device networking server.
Configure serial port parameters: Serial device networking server can modify parameters through configured computer tools or web pages. The main differences between the two methods are: the serial device networking server must be in the same subnet as the computer when parameters need to be modified through the web page.
Configure network parameters: The serial device networking server must have an IP that can be configured to be static or obtained through a DHCP server. The working modes of the serial device networking server include TCP server mode, TCP client mode, and UDP mode. The server mode means that the computer actively searches for a serial device networking server; the client mode means that the serial device networking server actively searches for a computer. The purpose of configuring network parameters is to allow the computer to successfully establish a connection with the networking server.
Enable the virtual serial port: Since the PC software of the general user still opens the serial port to communicate with the device, at this time, due to the use of the network, a serial port must be virtualized on the computer (the serial device networking server having software can virtualize the serial port), and the virtual serial port is responsible for connecting with the serial device networking server and forwards the data to the user program that opens the virtual serial port.
Run the user device communication program and open the virtual serial port. After that, the user application program can communicate with the device.