Serial to Ethernet serial port wifi RS485 to Ethernet RS232 to Wifi module how to set up
The company's serial port to the Ethernet and serial to Wifi wireless equipment, the actual serial data is used as TCP / IP application layer data, with TCP / IP encapsulation transmission. It can be carried with any serial port, network port and PLC for wireless or wired communication. This paper mainly completes the design of the host computer configuration software of the serial port to Ethernet module. According to the communication protocol between the host computer and the serial port Ethernet module, the UDP broadcast mode is used to complete the parameter configuration of the module, which is convenient for the user to use the module. 1, Siemens S7-200 Smart PLC wireless communication 1.1, ZP-8111, ZP-8621, ZP-8811 series and S7-200Smart PLC wireless communication between: With the ZP-8811 serial port WIFI module can be Siemens S7-200Smart PLC Ethernet port into wireless WiFi communication, as shown in Figure 1-1, only one of the modules set to AP mode, the other modules set to STA and Establish a wireless WiFi connection, you can use the wireless way to replace the original use of Ethernet switches when the wired connection. The IP address of each device (PLC, PC, HMI) is still the IP address of the previous wired connection. The AP interface of the AP module and STA module is transparently transmitted and not translated. To prevent the ZP-8811 from automatically assigning an IP address to the connected device (if the connected device is set to "Obtain an IP address automatically"), the ZP-8811's DHCP server can be disabled. 1.2, computer and S7-200Smart PLC wireless programming monitoring communication: Will be connected to the Siemens S7-200Smart PLC set the ZP-8811 AP, you can use the built-in WiFi built with the laptop wireless connection, such as upload, download procedures, monitoring and other operations.
1 ZP-8111, ZP-8621, ZP-8811 series and serial to Ethernet module Serial to Ethernet is actually the serial communication data into a network packet issued by the network packets will be received in the form of serial communication issued to achieve the serial port and the data between the network port transparent transmission. This article uses USR-TCP232-E45 serial to Ethernet module. The module is equipped with ARM processor, using Cortex-M3 core, the internal integration of the LWIP protocol stack, fast, low power consumption, stable and reliable. The parameters to be configured before using the module include serial interface parameters  (baud rate, data bit, parity bit, stop bit) and network parameters (operating mode, IP address, port number, subnet mask, gateway, etc. ). 2, UDP broadcast principle Broadcast: A node sends a packet, and all nodes in the network can receive it. If the two hosts on the network to communicate with each other, one to know each other's IP; the second to know the program can listen to the port, because the same host on the use of the network through the port number to distinguish. If you want to broadcast data over the entire network, you want to send data packets to 255.255.255.255, which will not be routed, it will only reach all hosts in the physical network, because if the router forwards the broadcast message, Causing the network to be paralyzed. The broadcast needs to indicate the port number of the recipient, since it is not possible for all the ports of the recipient to listen to the broadcast, so the communication must ensure that the destination port number and the local port number are not occupied.