In the field of Industrial Internet of Things, RS485 to Ethernet Converters play a crucial role as a bridge connecting serial devices to the network. However, in practical applications, we sometimes encounter situations where the RS485 to Ethernet Converter fails to recognize TCP packets, often due to the mode settings of the RS485 to Ethernet Converter. From the perspective of a senior engineer, this article aims to explain this phenomenon and its underlying reasons to traditional industries.
Firstly, it's essential to understand the operating modes of a RS485 to Ethernet Converter. RS485 to Ethernet Converters typically offer various operating modes, with transparent transmission mode being the most common and straightforward. In transparent transmission mode, the RS485 to Ethernet Converter directly converts serial data into network data (such as TCP packets) for transmission and vice versa. This seamless integration between serial devices and network devices eliminates the need for complex protocol conversions.
However, if the RS485 to Ethernet Converter is set to a mode other than transparent transmission, such as AT command mode or MODBUS TCP mode, it will not directly recognize TCP packets. This is because these modes often have specific data formats and communication protocols that require processing and conversion according to defined rules. For instance, in AT command mode, the RS485 to Ethernet Converter controls and manages network connections and data transmission through specific AT commands. Similarly, in MODBUS TCP mode, the RS485 to Ethernet Converter parses and encapsulates data according to the MODBUS protocol specifications.
Therefore, when a RS485 to Ethernet Converter is not set to transparent transmission mode, it cannot directly recognize TCP packets. This is because TCP packets are based on the network layer protocol, while the RS485 to Ethernet Converter in non-transparent modes may operate at the application layer or other levels, using different protocols and rules for data processing. In such cases, attempting to send TCP packets to the RS485 to Ethernet Converter may result in malfunction due to its inability to parse these packets.
To address this issue, we need to choose the appropriate operating mode for the RS485 to Ethernet Converter based on the actual application scenario and requirements. If direct communication between serial devices and network devices is desired, transparent transmission mode is usually the most suitable choice. However, for more complex network control or data processing, other modes may be necessary, and corresponding programs may need to be written to adapt to the communication protocols and data formats of these modes.
It's also worth noting that the configuration and settings of the RS485 to Ethernet Converter are crucial factors affecting its ability to recognize TCP packets. When using a RS485 to Ethernet Converter, it's essential to carefully read its manual or instructions, understand the meaning and setting methods of various configuration parameters, and ensure that the RS485 to Ethernet Converter's parameters and operating mode are correctly configured.
When a RS485 to Ethernet Converter is not set to transparent transmission mode, it cannot recognize TCP packets because it processes and converts data according to specific operating modes and protocol rules, unable to directly parse TCP packets at the network layer. Therefore, when using a RS485 to Ethernet Converter, we need to select the appropriate operating mode based on actual needs and configure relevant parameters correctly to ensure its normal operation and satisfaction of application requirements.
