A DTU and an industrial gateway both connect field equipment, but they solve different problems. A DTU is simpler and more economical when one or a few serial devices only need raw data transport. A gateway is more suitable for register parsing, normalized tags, protocol conversion, local buffering or multiple platforms. Tespro TD-DTU Series devices fit passthrough, while TG gateways such as TG-324 and TG-325 fit multi-protocol and edge-processing projects.
When to choose a DTU
Use a DTU when the protocol is known, the server parses it, and the field only needs a TCP, UDP or MQTT path.
When a gateway is required
Use a gateway for multiple protocols, serial ports, many points, polling, scaling, alarms, buffering or MQTT/OPC UA publishing.
Combining Tespro Gateways and DTUs
Use TD-DTU-SE, TD-DTU-PRO or TD-DTU-PLUS at distributed sites with simple protocols, and TG-324 or TG-325 at multi-protocol, multi-serial or data-modeling sites. Larger systems can use distributed DTUs with TG gateway or platform aggregation in a layered architecture.
Selection and RFQ checklist
✓ Passthrough or parsing
✓ Device and serial-port count
✓ Local logic and alarms
✓ Buffering and replay
✓ Number of platforms
✓ Budget and expansion
Frequently asked questions
Q: Should a project use a Tespro TG gateway or a TD-DTU?
A: Choose a TD-DTU Series device when the main task is reliable serial-data transport. Choose a TG Series gateway, such as TG-324 or TG-325, when the project requires register parsing, Modbus-to-MQTT or OPC UA conversion, multi-device aggregation, buffering, or edge processing.
Q: Can a DTU convert Modbus to MQTT?
A: Distinguish between carrying Modbus frames through an MQTT channel and parsing registers into MQTT topics or JSON data. Some DTU solutions may support the first workflow, while the second normally requires gateway functions. Do not assume every DTU provides full conversion.
Q: Is an industrial gateway always more reliable than a DTU?
A: No. Reliability depends on hardware, power, network design, software recovery, installation, and configuration. The correct choice is the device whose functions and processing load match the project.
Q: Can gateways and DTUs be used in the same project?
A: Yes. TD-DTU devices can provide economical access for simple distributed equipment, while TG Series gateways can handle multi-protocol sites or aggregation layers before sending normalized data to the platform.
