TGW-718 Modbus RTU/ASCII to Modbus TCP PoE Device Server

A compact, low-power PoE gateway designed to link Ethernet-based Modbus hosts with serial Modbus RTU/ASCII instruments. Supports Modbus TCP/UDP master and slave and supports Modbus RTU/ASCII master and slave. Max. TCP connections (masters) per serial port: 32. A read-cache is provided to speed Modbus TCP/UDP responses, and a UDP responder (UDP Search) simplifies device discovery on the network. Network configuration can be static IP or DHCP, and firmware can be updated over Ethernet using BOOTP or TFTP. Configuration is also available via a tiny built-in web server (HTTP). Hardware and connectivity include a 32-bit MCU for efficient network handling, 10/100 Base-TX Ethernet with RJ-45 x 1 (Auto-negotiating, auto MDI/MDIX, LED Indicators), and redundant power inputs: PoE (IEEE 802.3af, Class 1) plus a DC jack. The unit features automatic RS-485 direction control, a terminal block connector for straightforward wiring, and a small form-factor with low power consumption. RoHS compliant & no Halogen. A cost-effective Modbus gateway solution. The tGW-715 is a Modbus TCP to RTU/ASCII gateway that enables a Modbus/TCP host to communicate with serial Modbus RTU/ASCII devices over an Ethernet network, removing the cable-length limits of traditional serial links. It can be configured for pair-connection, serial-bridge, or serial-tunnel applications to route TCP/IP traffic between two serial Modbus RTU/ASCII devices—useful for connecting servers, mainframes, or other serial-only equipment to Ethernet networks. For reliability the module includes a dual watchdog: a CPU watchdog that resets the CPU if the embedded firmware behaves abnormally, and a host watchdog that resets the CPU if communication with the host (PC or PLC) is lost for a predefined system timeout period. This dual-watchdog design helps ensure continuous operation even in challenging environments. The tGW-700 series (for i version) also adds 3000 VDC isolation and +/-4 kV ESD protection components that divert potentially damaging charge away from sensitive circuitry, protecting the module and connected equipment from sudden, momentary electrical discharges.