--- title: "GTD Therm" description: "GTD Therm wall-mount thermostat panel connected to TapHome via Modbus TCP. Temperature control, fan speed, LCD display and touch buttons." url: "https://taphome.com/en/compatibility/gtdtherm/" language: en lastmod: 2026-03-30 generator: hugo ai: topics: ["modbus-tcp","thermostat","hvac","ethernet","temperature-control","fan-speed"] questions: ["How to integrate GTD Therm thermostat with TapHome?","What does the GTD Therm TapHome template control?","How to connect GTD Therm via Modbus TCP to TapHome?","How to change fan speed on GTD Therm via TapHome?","What are the impulse buttons on the GTD Therm panel?","How does the LCD display selector work on GTD Therm?"] --- # GTD Therm Communication: Modbus TCP - [GTD IOT Product Page (same manufacturer)](https://gtdiot.en.made-in-china.com/product/eniRXBoGOfWx/China-OEM-LED-Bedside-Control-8-Buttons-Panel-Touch-Light-Dimmer-Control-Smart-Wall-Switches-with-12-24V-RS-485-Modbus.html) > Network address > > TapHome reaches this device at the address entered on import. Give the device a fixed address — an IP reservation in the router, or its mDNS name if it supports one — otherwise the integration stops working when the router changes the address. > > [Network Preparation](https://taphome.com/en/docs/setup/network-preparation/) ## Integration guide The GTD Therm is a wall-mount HVAC thermostat panel from GTD IOT that communicates via Modbus TCP over Ethernet. It provides temperature control with current and desired temperature reading/writing, a 10-level fan speed selector, LCD display content selection, panel backlight control, and impulse touch buttons for power, fan min/max and mode cycling. TapHome connects directly to the panel over the local network — no additional gateway is required. The template uses the MODBUSWNE (write-no-echo) pattern for all write operations and polls the device at 2500 ms intervals. ## Network connection Connect the GTD Therm panel to the same local network as TapHome Core using a standard Ethernet cable. - **Protocol:** Modbus TCP - **Port:** 502 - **Default Slave ID:** 1 ## Configuration No special configuration is needed on the GTD Therm panel. The Modbus TCP interface is active by default on port 502. When importing the template in TapHome, provide: - **IP Address** — the panel's IP on the local network (default: 192.168.0.1) - **Slave ID** — Modbus slave address (default: 1) ## Device capabilities The template exposes 9 devices: a thermostat, fan speed selector, LCD display parameter, panel backlight, 4 impulse buttons and a run mode switch. ### Thermostat The thermostat device provides temperature control with two registers: - **Current temperature** — read from H:30 (Int16 / 10), displays the measured room temperature in °C - **Desired temperature** — read from H:31 (Int16 / 10) and writable via MODBUSWNE. The value is multiplied by 10 before writing (e.g. 22.5 °C is written as 225) ### Fan speed A multi-value switch on register H:32 with 10 selectable levels: | Value | Name | |-------|------| | 0 | OFF | | 1 | MIN | | 2 | NORMAL | | 3 | MAX | | 4–9 | Extended speed levels | ### LCD display parameter A multi-value switch on register H:45 that controls what the panel's LCD screen displays: | Value | Display content | |-------|----------------| | 0 | Setpoint temperature | | 1 | Current temperature | | 2 | Fan speed | | 3 | Display value | | 4–9 | Extended display options | ### Panel backlight On/off switch on register H:24 (Bool) to control the thermostat panel backlight. ### Impulse touch buttons Four impulse-type switches that emulate physical button presses on the panel. Each sends a momentary on/off signal via MODBUSWNE: | Button | Register | Function | |--------|----------|----------| | ON/OFF | H:2 | Power on/off toggle | | Fan Speed Min | H:3 | Set fan to minimum speed | | Fan Speed Max | H:4 | Set fan to maximum speed | | Mode | H:5 | Cycle through operating modes | These impulse buttons mirror the physical touch buttons on the panel and allow triggering the same actions remotely from TapHome or via Smart Rules. ### Run mode On/off switch on register H:33 (Bool) indicating whether the thermostat is actively running (heating/cooling active). ## Register summary | Device | Register | Data type | Read/Write | Poll interval | |--------|----------|-----------|------------|---------------| | Thermostat (current temp) | H:30 | Int16 (÷10) | Read | 2500 ms | | Thermostat (desired temp) | H:31 | Int16 (÷10) | Read/Write | 2500 ms | | Fan Speed | H:32 | Int16 | Read/Write | 2500 ms | | Run Mode | H:33 | Bool | Read/Write | 2500 ms | | Panel Backlight | H:24 | Bool | Read/Write | 2500 ms | | ON/OFF Button | H:2 | Bool | Read/Write | 2500 ms | | Fan Min Button | H:3 | Bool | Read/Write | 2500 ms | | Fan Max Button | H:4 | Bool | Read/Write | 2500 ms | | Mode Button | H:5 | Bool | Read/Write | 2500 ms | | LCD Display Parameter | H:45 | Int16 | Read/Write | 2500 ms | ## Troubleshooting ### No Modbus communication 1. Verify the Ethernet cable is connected and the panel is powered 2. Confirm the panel's IP address — check the router's DHCP lease table 3. Ensure TapHome Core and the GTD Therm are on the same network/subnet 4. Check that no firewall is blocking port 502 ### Temperature reads as 0 or incorrect value The thermostat uses Int16 with a ÷10 conversion. A raw register value of 225 means 22.5 °C. If readings appear 10x too high or too low, verify the template is using the correct conversion factor. ## Available devices 9 These devices appear in TapHome after import. GTDTherm Module Thermostat Thermostat Read and write Temperature control — reads current temperature from H:30, reads/writes desired temperature on H:31 (Int16 ÷10, °C) Register: H:30, H:31 → H:31 Int16 Unit: °C numeric Read temperature ```taphome MODBUSR(H, 30, Int16) / 10 ``` Read desired temperature ```taphome MODBUSR(H, 31, Int16) / 10 ``` Write desired temperature ```taphome MODBUSWNE(H, 31, Int16, Se * 10) ``` Fan Speed Multi-value Switch Read and write Fan speed selector with 10 levels — 0=OFF, 1=MIN, 2=NORMAL, 3=MAX, 4–9 extended speeds Register: H:32 Int16 numeric Values / States: OFF · MIN · NORMAL · MAX Read switch state ```taphome MODBUSR(H, 32, Int16) ``` Write switch state ```taphome MODBUSWNE(H, 32, Int16, Mu) ``` LCD Display Parameter Multi-value Switch Read and write LCD screen content selector — 0=Setpoint, 1=Current Temperature, 2=Fan Speed, 3=Display value, 4–9 extended Register: H:45 Int16 numeric Values / States: Setpoint · Current Temperature · Fan Speed Read switch state ```taphome MODBUSR(H, 45, Int16) ``` Write switch state ```taphome MODBUSWNE(H, 45, Int16, Mu) ``` Panel Backlight Switch Read and write On/off control for the thermostat panel backlight — reads/writes H:24 Register: H:24 Bool Values / States: ON · OFF Read switch state ```taphome MODBUSR(H, 24, Bool) ``` Write switch state ```taphome MODBUSWNE(H, 24, Bool, St) ``` ON/OFF Button Switch Read and write Impulse touch button for thermostat power on/off — reads/writes H:2 Register: H:2 Bool Values / States: ON · OFF Read switch state ```taphome MODBUSR(H, 2, Bool) ``` Write switch state ```taphome MODBUSWNE(H, 2, Bool, St) ``` Fan Speed Min Button Switch Read and write Impulse touch button to set fan speed to minimum — reads/writes H:3 Register: H:3 Bool Values / States: ON · OFF Read switch state ```taphome MODBUSR(H, 3, Bool) ``` Write switch state ```taphome MODBUSWNE(H, 3, Bool, St) ``` Fan Speed Max Button Switch Read and write Impulse touch button to set fan speed to maximum — reads/writes H:4 Register: H:4 Bool Values / States: ON · OFF Read switch state ```taphome MODBUSR(H, 4, Bool) ``` Write switch state ```taphome MODBUSWNE(H, 4, Bool, St) ``` Mode Button Switch Read and write Impulse touch button to cycle through operating modes — reads/writes H:5 Register: H:5 Bool Values / States: ON · OFF Read switch state ```taphome MODBUSR(H, 5, Bool) ``` Write switch state ```taphome MODBUSWNE(H, 5, Bool, St) ``` Run Mode Switch Read and write On/off switch for thermostat run mode (heating/cooling active) — reads/writes H:33 Register: H:33 Bool Values / States: ON · OFF Read switch state ```taphome MODBUSR(H, 33, Bool) ``` Write switch state ```taphome MODBUSWNE(H, 33, Bool, St) ``` **Connection:** Modbus TCP • Slave ID: $\[SlaveId] ## Import parameters Enter these values when you import the XML. | Asked in the app | Default | |------------------|---------------| | Slave ID | `1` | | IP address | `192.168.0.1` | ## Sources - GTD IOT Product Page (same manufacturer) [gtdiot.en.made-in-china.com](https://gtdiot.en.made-in-china.com/product/eniRXBoGOfWx/China-OEM-LED-Bedside-Control-8-Buttons-Panel-Touch-Light-Dimmer-Control-Smart-Wall-Switches-with-12-24V-RS-485-Modbus.html) 2026-03-30 ## Related Documentation - [Modbus Integration](https://taphome.com/en/compatibility/modbus-guide/) - [Modbus](https://taphome.com/en/docs/integration/modbus/) - [Simple configuration using templates](https://taphome.com/en/docs/integration/modbus/templates/) - [Modbus scripts and prefetch](https://taphome.com/en/docs/script/modbus-scripts/) - [Modbus functions](https://taphome.com/en/docs/script/modbus/) - [Modbus data types](https://taphome.com/en/docs/script/modbus-data-types/)