Sentera · Fan controller
ECH-8-DM controller for water heaters / coolers with EC fan Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 1-based
- Byte order
- Big endian
- Word order
- High word first
- Baud rate
- 19200
- Parity
- Even
- Data bits
- 8
- Stop bits
- 1
This device has an RS-485 interface. Reach it through a Modbus RTU-to-TCP gateway, configured with the factory serial settings above.
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 1 | 1 | Operating mode 0 = standby, 1...5 = position 1...5, 6 = auto mode, 7 = remote mode. | UInt16 | - | 1 | R |
| 2 | 1 | Temperature sensor state 0 = connected, 1 = not connected or temperature above the working range, 2 = short circuit or temperature below the working range, 3 = not calibrated. | UInt16 | - | 1 | R |
| 3 | 1 | Temperature setpoint Raw 50...350 = 5.0...35.0 °C. | UInt16 | °C | 0.1 | R |
| 4 | 1 | Actual temperature Raw -100...500 = -10.0...50.0 °C. | Int16 | °C | 0.1 | R |
| 5 | 1 | Relay output state 0 = off / 0 VAC, 1 = on / supply voltage. | UInt16 | - | 1 | R |
| 6 | 1 | Analogue output mode 0 = 0...6 VDC, 1 = 0...10 VDC. | UInt16 | - | 1 | R |
| 7 | 1 | Analogue output value Raw 0...1000 = 0.0...100.0 % output. | UInt16 | % | 0.1 | R |
| 8 | 1 | Control mode 0 = cooling, 1 = heating. | UInt16 | - | 1 | R |
| 9 | 1 | LED indication 0 = overwrite, 1 = blue, 2 = cyan, 3 = green, 4 = yellow, 5 = red, 6 = white. | UInt16 | - | 1 | R |
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Related guides
Notes
Source: Sentera 'ECH-8-DM Controller for water heaters / coolers with EC fan - Modbus register map', MBRM-ECH-8-DM-EN-000 dated 07/06/2024, vendor-hosted PDF at https://www.sentera.eu/en/files/article/document/mbrm/ech-8-dm-modbus-register-map-1266049.pdf (SHA-256 e43e24cc4dd34957b376e103f54c99c1a636fa032e476a61cbf82037e666979a), linked from the 'Modbus register map' entry on the product page at the URL above (opened 7 Nov 2026): page 2 input registers, pages 3-4 holding registers. That page now also serves a newer, unversioned edition (no document code, no date) whose holding map runs to register 34, prints FW 0x0130 = 1.3 and calls the 'Remote mode' of input register 1 and holding register 20 'Overwrite mode'; this seed transcribes only the dated edition it cites. Factory settings from the holding-register table's 'Factory default values' column: slave address 1, baud rate 2 (19200 bps out of 0 = 4800, 1 = 9600, 2 = 19200, 3 = 38400, 4 = 57600, 5 = 115200, 6 = 230400), parity 1 (8E1 out of 0 = 8N1, 1 = 8E1, 2 = 8O1). Addressing: the map numbers its input registers 1...9 and holding registers 1...24 with no wire address or frame example, which is the supplier's 1-based register numbering (Modbus register 1 = address 0x0000), so the seed declares one_based and stores the numbers exactly as printed. Scaling is taken from the document's own raw/engineering pairs: temperature and the proportional range in 0.1 °C steps, analogue output positions and the overwrite value in 0.1 % steps (0...1000 = 0.0...100.0 %). The register numbered 7 in the holding block is documented only as 'Reserved, returns 0' and is left out, which is why the holding block skips from 6 to 8. The device is a general-purpose EC-fan / heater-cooler controller for greenhouse, shed and stable ventilation, and its input registers expose the fan output, setpoint and actual temperature.