Dometic LIN Protocol
Overview
Dometic devices use LIN protocol for communication across their range of motorhome and RV equipment. Each device type uses specific frame IDs for control and status reporting.
Device Types
The following table shows the LIN identification parameters and frame IDs for Dometic devices (Supplier ID: 0x1234):
| Device | NAD | Function ID | Variant ID | Control Frame ID | Info Frame ID |
|---|---|---|---|---|---|
| Absorber Refrigerator | 0x0B | 0x0000 | 0x00 | 0x0B | 0x0C |
| Compressor Refrigerator | 0x02 | 0x0C01 | 0x00 | 0x0B | 0x0C |
| Inverter | – | – | – | 0x1C | 0x1D |
| Air Conditioning | – | – | – | 0x08 | 0x17 |
| Roof Vent | 0x20 | 0x0010 | 0x00 | – | – |
| Freshjet | 0x18 | 0x0004 | 0x06 | – | – |
| Freshjet Inverter | 0x18 | 0x0004 | 0x07 | – | – |
| Solar Charger | 0x01 | 0x0000 | 0x01-0x06 | – | 0x20 |
| Battery Charger | – | – | – | 0x15/0x18 | 0x16/0x19 |
Common Protocol Elements
Frame Structure
All Dometic devices follow the standard LIN frame structure:
- Control Frames: Commands sent to devices (master → slave)
- Info Frames: Status responses from devices (slave → master)
BCD Encoding
Some Dometic devices (notably refrigerators) use Binary Coded Decimal (BCD) encoding for time values:
- Each decimal digit is stored in 4 bits (nibble)
- Example: 0x14 =
0001 0100= 1×10 + 4×1 = 14
Reserved Bytes
Most frames include reserved bytes (typically 0xFF) for future protocol expansion.
Protocol References
- Dometic devices typically operate at 19,200 bps baud rate
- Frame length is 8 bytes for data payload
- Communication follows master-slave pattern with LIN master initiating all transactions