For a long time, serial communication methods have been widely used in many fields such as data collection, data monitoring, security, and medical care. However, with the development of the Internet and the improvement of application requirements, its limitations have become increasingly prominent : short communication distance, low speed, network Characteristics are poor. At the same time, the rapid development of the Internet of Things has made the need for embedded device networking more and more urgent to eliminate existing serial port equipment. The development of new products that can be connected to the Internet requires a lot of time, manpower and material resources. In contrast, using serial port to Ethernet With this technology, you only need to add a serial port to Ethernet module without eliminating the original serial port equipment. This not only improves equipment utilization, but also reduces development costs, shortens the development cycle, and easily enables serial port device networking.
Serial port to Ethernet actually uses serial port data as TCP/IP application layer data and uses TCP/IP encapsulation for transmission 12-31. This article mainly completes the design of the host computer configuration software for the serial port to Ethernet module. According to the communication protocol between the host computer and the serial port to Ethernet module, UDP broadcast method is used to complete the parameter configuration of the module to facilitate users to use the module.
ZHC1931 is a network IO product that supports 2 channels of dry (wet) node detection, 1 channel of relay (COM, NO) output, 1 channel of analog quantity (current 4~20mA) detection, and 2 channels of serial port transparent transmission . It is compatible with Modbus RTU/ TCP protocol. With “remote control” as the core function and high ease of use, users can easily and quickly integrate it into their own systems to achieve remote and local control based on Ethernet, RS485, and RS232.
Serial to Ethernet module function
√ 1 relay output
√ 2 DI (dry/wet node) inputs
√ 1 analog (current) input
√ TCP_Client/ MQTT_Client/ TCP_Server
√ Modbus RTU/TCP
√ Host and slave modes, the host mode supports RS485 cascading of multiple devices
√ Cloud forwarding, cloud networking
√ Local logic, inter-device logic
√ Network registration package, heartbeat package
√ Hardware watchdog
√ Remote configuration and remote upgrade
√ Host computer, web page
√ Data triggering and regular reporting
To configure the parameters of the serial port to Ethernet module, the host computer needs to send corresponding commands (data messages) to the module according to a certain communication protocol. The communication protocol consists of message header, message length, and message content. message sent by the host computer also has a 1 B check code at the end. The response of the module to the host computer does not have a check, as shown in Table 1. Show. Adding verification to the communication protocol can well solve the problem of transmission errors; the receiver verifies the received data. If the verification value is incorrect, the packet of data is discarded and the sender is notified.