A DL/T645 to Modbus gateway is a device that enables communication between devices using the DL/T645 protocol and devices using the Modbus protocol. Similarly, an IEC 104 to Modbus gateway facilitates communication between devices using the IEC 104 protocol and devices using the Modbus protocol.

DL/T645 is a communication protocol widely used in China for smart metering and energy management systems. It defines the format and rules for data exchange between energy meters and data collection systems. On the other hand, Modbus is a common protocol used for communication between various industrial devices.

BL120DT gateway acts as an intermediary, allowing devices using the Modbus protocol to read data from and write data to devices using the DL/T645 protocol. It performs protocol conversion and data mapping between the two protocols, ensuring seamless communication between the different devices.

BL120DT gateway serves the same purpose but for devices using the IEC 104 protocol and Modbus protocol. The IEC 104 protocol is commonly used in power system automation and SCADA (Supervisory Control and Data Acquisition) applications.