Thermia (Danfoss) · Heat pump
Mega / Genesis platform heat pumps Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 0-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 |
|---|---|---|---|---|---|---|
| 3 | 1 | Reset all alarms Reference address 3, de facto 4, scale 1. | UInt16 | - | 1 | RW |
| 5 | 1 | Enable external additional heater Reference address 5, de facto 6, scale 1. | UInt16 | - | 1 | RW |
| 7 | 1 | Enable flow switch/pressure switch Reference address 7, de facto 8, scale 1. | UInt16 | - | 1 | RW |
| 8 | 1 | Enable tap water Reference address 8, de facto 9, scale 1. | UInt16 | - | 1 | RW |
| 9 | 1 | Enable heat Reference address 9, de facto 10, scale 1. | UInt16 | - | 1 | RW |
| 10 | 1 | Enable active cooling Reference address 10, de facto 11, scale 1. | UInt16 | - | 1 | RW |
| 11 | 1 | Enable mix valve 1 Reference address 11, de facto 12, scale 1. | UInt16 | - | 1 | RW |
| 12 | 1 | Enable TWC Reference address 12, de facto 13, scale 1. | UInt16 | - | 1 | RW |
| 13 | 1 | Enable WCS Reference address 13, de facto 14, scale 1. | UInt16 | - | 1 | RW |
| 14 | 1 | Enable hot gas pump Reference address 14, de facto 15, scale 1. | UInt16 | - | 1 | RW |
| 16 | 1 | Enable mix valve 2 (EM) Reference address 16, de facto 17, scale 1. | UInt16 | - | 1 | RW |
| 17 | 1 | Enable mix valve 3 (EM) Reference address 17, de facto 18, scale 1. | UInt16 | - | 1 | RW |
| 18 | 1 | Enable mix valve 4 (EM) Reference address 18, de facto 19, scale 1. | UInt16 | - | 1 | RW |
| 19 | 1 | Enable mix valve 5 (EM) Reference address 19, de facto 20, scale 1. | UInt16 | - | 1 | RW |
| 20 | 1 | Enable brine out monitoring Reference address 20, de facto 21, scale 1. | UInt16 | - | 1 | RW |
| 21 | 1 | Enable brine pump continuous operation Reference address 21, de facto 22, scale 1. | UInt16 | - | 1 | RW |
| 22 | 1 | Enable system circulation pump Reference address 22, de facto 23, scale 1. | UInt16 | - | 1 | RW |
| 23 | 1 | Enable dew point calculation Reference address 23, de facto 24, scale 1. | UInt16 | - | 1 | RW |
| 25 | 1 | Enable additional heater only (No compressor). Requires Operation mode: Standby Reference address 25, de facto 26, scale 1. | UInt16 | - | 1 | RW |
| 26 | 1 | Enable current limitation Reference address 26, de facto 27, scale 1. | UInt16 | - | 1 | RW |
| 28 | 1 | Enable pool (EM) Reference address 28, de facto 29, scale 1. | UInt16 | - | 1 | RW |
| 29 | 1 | Enable surplus heat, chiller (no borehole) Reference address 29, de facto 30, scale 1. | UInt16 | - | 1 | RW |
| 30 | 1 | Enable surplus heat, borehole (no chiller) Reference address 30, de facto 31, scale 1. | UInt16 | - | 1 | RW |
| 31 | 1 | Enable external additional heater for pool (EM) Reference address 31, de facto 32, scale 1. | UInt16 | - | 1 | RW |
| 33 | 1 | Enable passive cooling (EM) Reference address 33, de facto 34, scale 1. | UInt16 | - | 1 | RW |
| 34 | 1 | Enable variable speed mode for condenser pump Reference address 34, de facto 35, scale 1. | UInt16 | - | 1 | RW |
| 35 | 1 | Enable variable speed mode for brine pump Reference address 35, de facto 36, scale 1. | UInt16 | - | 1 | RW |
| 37 | 1 | Enable outdoor temp dependent for cooling with mixing valve 1 Reference address 37, de facto 38, scale 1. | UInt16 | - | 1 | RW |
| 38 | 1 | Enable internal brine pump to start when cooling is active for mixing valve 1 Reference address 38, de facto 39, scale 1. | UInt16 | - | 1 | RW |
| 39 | 1 | Enable outdoor temp dependent for external heater Reference address 39, de facto 40, scale 1. | UInt16 | - | 1 | RW |
| 40 | 1 | Enable brine in monitoring Reference address 40, de facto 41, scale 1. | UInt16 | - | 1 | RW |
| 41 | 1 | Enable fixed system supply set point, allows defacto address 40117 Reference address 41, de facto 42, scale 1. | UInt16 | - | 1 | RW |
| 42 | 1 | Enable evaporator freeze protection Reference address 42, de facto 43, scale 1. | UInt16 | - | 1 | RW |
| 43 | 1 | Enable outdoor temp dependent for cooling with mixing valve 2 (EM3 only)*5 Reference address 43, de facto 44, scale 1. | UInt16 | - | 1 | RW |
| 44 | 1 | Enable dew point calculation on mixing valve 2, requires room sensor for mixing valve 2 (EM3 only) Reference address 44, de facto 45, scale 1. | UInt16 | - | 1 | RW |
| 45 | 1 | Enable outdoor temp dependent for heating with mixing valve 2 (EM3 only)*5 Reference address 45, de facto 46, scale 1. | UInt16 | - | 1 | RW |
| 46 | 1 | Enable outdoor temp dependent for cooling with mixing valve 3 (EM3 only)*5 Reference address 46, de facto 47, scale 1. | UInt16 | - | 1 | RW |
| 47 | 1 | Enable dew point calculation on mixing valve 3, requires room sensor for mixing valve 3 (EM3 only) Reference address 47, de facto 48, scale 1. | UInt16 | - | 1 | RW |
| 48 | 1 | Enable outdoor temp dependent for heating with mixing valve 3 (EM3 only)*5 Reference address 48, de facto 49, scale 1. | UInt16 | - | 1 | RW |
| 49 | 1 | Enable outdoor temp dependent for cooling with mixing valve 4 (EM3 only)*5 Reference address 49, de facto 50, scale 1. | UInt16 | - | 1 | RW |
| 50 | 1 | Enable dew point calculation on mixing valve 4, requires room sensor for mixing valve 4 (EM3 only) Reference address 50, de facto 51, scale 1. | UInt16 | - | 1 | RW |
| 51 | 1 | Enable outdoor temp dependent for heating with mixing valve 4 (EM3 only)*5 Reference address 51, de facto 52, scale 1. | UInt16 | - | 1 | RW |
| 52 | 1 | Enable outdoor temp dependent for cooling with mixing valve 5 (EM3 only)*5 Reference address 52, de facto 53, scale 1. | UInt16 | - | 1 | RW |
| 53 | 1 | Enable dew point calculation on mixing valve 5, requires room sensor for mixing valve 5 (EM3 only) Reference address 53, de facto 54, scale 1. | UInt16 | - | 1 | RW |
| 54 | 1 | Enable outdoor temp dependent for heating with mixing valve 5 (EM3 only)*5 Reference address 54, de facto 55, scale 1. | UInt16 | - | 1 | RW |
| 55 | 1 | Enable internal brine pump to start when cooling is active for mixing valve 2 (EM3 only) Reference address 55, de facto 56, scale 1. | UInt16 | - | 1 | RW |
| 56 | 1 | Enable internal brine pump to start when cooling is active for mixing valve 3 (EM3 only) Reference address 56, de facto 57, scale 1. | UInt16 | - | 1 | RW |
| 57 | 1 | Enable internal brine pump to start when cooling is active for mixing valve 4 (EM3 only) Reference address 57, de facto 58, scale 1. | UInt16 | - | 1 | RW |
| 58 | 1 | Enable internal brine pump to start when cooling is active for mixing valve 5 (EM3 only) Reference address 58, de facto 59, scale 1. | UInt16 | - | 1 | RW |
| 59 | 1 | Enable continuous operation mode for condenser pump. Reference address 59, de facto 60, scale 1. | UInt16 | - | 1 | RW |
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Related guides
Notes
Source: Thermia AB “User Guide – Modbus protocol for Mega, Genesis platform”, document ACME01UG0502, version 12.00, vendor-hosted at https://www.thermia.fi/media/70526/protocol_doc-00079973.pdf (thermia.com). §2.3 Factory default: 19200 bps, even parity, address 1, 1 stop bit, 8 data bits, port 502, Modbus mode RTU (the same map is served over Modbus TCP). §2.2 documents both the de-facto 4xxxx/1xxxx/0xxxx numbering and the reference address to 0; this seed stores the reference address (the wire address) and declares zero_based. Values are 16-bit; §2.1 documents that negative values use the upper half of the register, so temperatures, pressures, currents, powers, percentages and season integrals are Int16 while hour counters, versions, gears, enums and bit fields are UInt16. Scale is the document's factor: scale 100 means multiply the raw value by 0.01, scale 10 by 0.1. The read-only block is read with function code 4, the writable block with 3/6/16 and the digital block with 1/5/15. Two coil rows in the document (addresses 62 and 63, de facto 61 and 62) contradict the document's own +1 rule and are left out. The asterisks the document prints in some row names (*1 to *7) have no legend in its section 2.4 table key, so they are carried over verbatim. Rows marked (EM) need the expansion module and (EM3) the EM3 card; they are listed because the address map is fixed, but they answer only on units that have the module. Compressor and tap-water operating hours are published as MSB/LSB 16-bit halves and are kept as two separate registers because the app has no 64-bit type.