GT-531 is an intelligent Modbus RTU SMS and voice alarm device. Control hosts such as PC, PLC, HMI, and PAC can send SMS or make phone calls and send pre-recorded voice messages to designated phone numbers using the Modbus RTU commands via RS-232 or RS-485 interface. The communication method of Modbus RTU allows control hosts to achieve fast and easy transmission of SMS alarms or voice alarms, making it suitable for M2M applications.
The GT-531 is an industrial data acquisition and control unit featuring a 32‑bit CPU, 64 KB SRAM, and 512 KB flash memory. It supports multiple communication interfaces, including RS‑232, RS‑485, Modbus RTU, and a GSM module for remote monitoring.
The manual details hardware specifications such as power requirements (+10 VDC ~ +30 VDC), DIN‑rail mounting, environmental limits (‑25 °C ~ +75 °C operating, ‑40 °C ~ +80 °C storage), and configuration registers for Modbus communication. It also includes instructions for SMS alerts, PIN/PUK handling, and wiring diagrams.
| CPU | 32‑bit |
|---|---|
| SRAM | 64 KB |
| Flash Memory | 512 KB |
| Supply Voltage | +10 VDC ~ +30 VDC |
| Dimensions (W×H×D) | 91 mm × 131 mm × 52 mm |
| Operating Temperature | -25 °C ~ +75 °C |
| Storage Temperature | -40 °C ~ +80 °C |
| Humidity | 5 % ~ 95 % RH (non‑condensing) |
The unit operates from a DC supply of +10 V to +30 V.
The device measures 91 mm wide, 131 mm high, and 52 mm deep.
It can operate from –25 °C up to +75 °C.