The Easiest Way to Bring DNP3 Serial Devices to Ethernet Based Networks
With device servers, raw socket mode allows the physical conversion from a serial interface to an Ethernet interface for serial protocols. The Ethernet-based DNP3 protocol includes the standard TCP/IP header and DNP3 serial frame, which is also referred to as DNP3 over TCP/IP. Coincidentally, by using serial tunneling technology, device servers can add serial-based protocol frames into standard TCP/IP packets to handle protocol conversion between DNP3-serial packets and DNP3-over TCP/IP packets. However, data that passes through device servers cannot be monitored, making it very difficult to identify the root cause of an abnormality during data transmissions.
Monitoring Protocol Conversion
Users who are looking for a more accurate means of monitoring protocol data transmissions to identify disruptions and abnormalities can use a protocol gateway. Protocol gateways not only convert serial-based DNP3 data packets into Ethernet-based packets, they also monitor and record these data packets through a tool built into the web console. The tool also supports debugging and maintenance functions. In addition, users can view the raw data and its routing direction, considerably reducing the commissioning time and debugging process when the system is in operation.
When Cross Conversion is Needed
Two methods can be used to integrate different communication protocols. The first method employs embedded computers, enabling engineers to write and compile software for specific purposes to fulfill customization demands. Such solutions, though, require a comprehensive knowledge of protocols. The second method relies on protocol gateways, featuring plug-and-play integration of configured interfaces for Modbus and DNP3 protocols. With a protocol gateway, users only need to set up the corresponding Modbus commands, DNP3 commands, and the memory exchange configuration; data exchange between the different protocols can be easily implemented once the system is configured. The only drawback is that the protocol gateway solution is pre-configured, meaning it lacks flexibility when new functions need to be added.
Embedded computers can easily play the role of data concentrator. Provided users have the programming ability, embedded computers can be used not only to collect, but also to analyze and filter data, allowing only processed data to be sent to the SCADA system.
Embedded computers, however, are not the best option when the requisite programming skill is lacking, or for systems that need to be implemented in a hurry. In these types of scenarios, a better option is to use protocol gateways that support agent mode, which actively and continuously retrieves data from connected devices. The updated data is stored in the gateway’s internal memory, and the SCADA system can retrieve this data directly from the gateway’s memory.