Protocol

This document reflects the current state of knowledge: It may contain errors and misassumptions.

General

Protocol: Half-Duplex USART (TX and RX on a single wire)
Baud-Rate: 9600bit/s
Transfer-Bits: 8
Stop-Bits: 2

Wiring

The heatpumps HMI controller board is based upon a STM32F103RFT6 and provides a 8-pin (2x4 2,54mm) connector.

The original setup needs 4 of those pins, which are connected to the main controller:

VCC 5V (green)
GND (red/brown)
TX/RX, Logical 5V (white)
Unknown/Unused(yellow)

Depending on the heatpump, sometimes there are only three wires.

Overview

The protocol uses an unknown binary frame format, with each message consisting of an unique identifier, payload length, payload and checksum.

Message Format

1 byte message identifier
1 byte payload Length
1-255 bytes payload
2 bytes checksum (CRC-16)

Example Messages:

ID LEN ----------------------------------------------- PAYLOAD ------------------------------------------------------------------ CRC16..
193 37 235 1 121   0 94   0 102   0 0  0   0 0 1 100  65 81  0   0   0 50 62 0 255 255 255 87  9 66 88   2   0  16  14   1 78  23 254 243
194 35  18 2  66 252  0 240  17 240 6 16  56 0 0 255 255  0 30 147  46 11 11 0   0 255   0  9 66  1  1 255 255 255 255 255         74 199
 67 31   0 0   0   0  0   0   0   0 0  0 181 9 0   0  23  0  0   0 181  9  0 0 168 195  18  0  0  0  0   0                         25  82
 74 35   0 0   0   0  0   0   0   0 0  0   0 0 0   0   0  0  0   0   0  0  0 0   0   0   0  0  0  0  0   0   0   0   0   0         18 176

Identifier

There are currently no insights, why they've chosen 193, 194, 67 and 74 and if there is an additional but yet unknown meaning in these identifiers

Checksum

The two byte checksum value is created using standard CRC-16/CCITT-FALSE. The checksum is created for payload length and the actual payload itself:

Example Message 67 in decimal and hexadecimal representation:

DEC: 31  0  0  0  0  0  0  0  0  0  0 181  9  0  0 23  0  0  0 181  9  0  0 168 195 18  0  0  0  0  0 25 82
HEX: 1F 00 00 00 00 00 00 00 00 00 00  B5 09 00 00 17 00 00 00  B5 09 00 00  A8  C3 12 00 00 00 00 00 19 52

In this message we expect an CRC of 0x1952 (last two bytes). Using the CRC-16/CCITT-FALSE algorithm we are able to successfully recreate the CRC values: See online crc result using crccalc.com

Messages

Messages are either send from the main or the hmi controller. The main controller is the master of the communication and is repeating a pattern of message identifiers. The message sequence during normal operation is:

194 (HMI)
56ms idle
67 (MAIN)
60ms idle
193 (MAIN)
150ms idle
(repeated)

If an error message is requested by the HMI controller, the sequence contains another message with identifier 74.

194 (HMI)
56ms idle
67 (MAIN)
60ms idle
193 (MAIN)
54ms idle
74 (MAIN)
56ms idle

In case we disconnect the HMI controller during operation, we will notice that the 194 frame is no longer complete:

Therefore, message 194 is completed by the HMI controller, whereas 193 and 67 are emitted by the main controller.

Send from the HMI controller

The main controller gives the HMI controller permission to send by emitting the 194 message type on the wire. The HMI controller completes the packet on the one-wire bus.

194

Byte Number	Example	Purpose/Function	Other Information
0	35	Length Field	-
1 - 2	18 2	Target Temp.	See Temperature Table, 53°C
3	66	OperationMode	See Operation Mode Table
4	252	Command: Change PWM, Command: Change Anti-Dry-Heating	See Commands
5	0	Anti-Legionella Mode / AirDuct Mode	0 == Off, 1 == 1perMonth, 2 == 2perMonth, 3 == 3perMonth, 4 == 4/perMonth, // 0 == AirDuct INT/INT, 16 == AirDuct EXT/INT, 32 == AirDuct EXT/EXT
6	240	Emergency-Mode, Command: Change Connectivity	"Emergency Mode Off == 240, Emergency Mode On == 241", "Disabled Connectivity: No == 240, Disabled Connectivity: Yes == 16"
7	17	InstallationConfig	WP-Only == 0, WP+ExtBoiler-Prio-WP == 1, Wp+ExtBoiler-Opt-WP == 17, Wp+ExtBoiler-Opt-ExtBoiler == 33 , Wp+ExtBoiler-Prio-ExtBoiler == 49 , WP + Solar == 50
8	240	ExhaustFanConfig, Command: Change Heat-Exchanger	Exhaust Fan Stop == 240, Low Speed == 241, High Speed == 242. See Commands
9	4	Heating-Element / SetupState / PV allowed	Heating-Element Automatic-Mode == 4, Heating-Element Disabled == 0, Setup Factory Settings == 164, Setup Airduct Set == 36, Setup Finished == 4 ... and PV allowed but not enabled = 4, PV allowed and enabled = 6
10	16	Timer Mode: Window 1 Start	16 = 04:00h, 12 = 03:00h
11	56	Timer Mode: Window 1 Length	52 = 13h runtime, 56 = 14h runtime
12	0	Timer Mode: Window 2 Start	e.g. 52 = 13:00h - Value 0x00 0x00 is supported if Timer 2 is not set.
13	0	Timer Mode: Window 2 Length	e.g. 16 = 04h runtime. Max allowed length of both timers in sum is 14h runtime
14	255	Command: Change PV-Input, Change Circulation	-
15	255	Command: Change Min Target Temperature	Note: Range 40-50°C
16	0	Command: Clear Alarm (Error Beeps)	0 == Noop, 4 == Clear Alarm / Errors
17	25	Current Time Seconds	-
18	151	Current Day, Current Month in Half-Year	See Formula below
19	46	Current Year, Half-Year	See Formula below
20	11	Current Time Minutes	-
21	13	Current Time Hour	-
22	0	TestMode Status	HMI Left TestMode == 0, HMI Entered TestMode == 1, Heatpump TestMode == 2, Heating-Element TestMode == 3, Fan-Slow TestMode == 4 , Fan-Fast TestMode == 5 , Defrost TestMode == 6, Heatpump + EXT Boiler TestMode == 8
23	0	?	-
24	255	Command: Change PWM Value, Contains PWM Setpoint	-
25	0	?	-
26	9	?	-
27	66	?	-
28	0	Command: Request Error Message / Error Number	Error Number (1..x)
29	0	Command: Request Error Message / Request Id	Upcounting (1..255
30	255	Command: Change Anti-Legionalla Temperature Target	See Commands. Note: Valid Range 62-70°C
31	255	Command: Change Installed Wattage Heat Element	See Commands. Note: Valid Range 10-30 (1000 - 3000W)
32	255	Command: Change Brand of Heat-Pump	See Commands.
33 - 34	255 255	Command: Change Boiler Capacity	See Commands.

Byte No. 3: Operation Mode

Findings...

2dec  | 0000 0010:  AlwaysOn + ECO Inactive
3dec  | 0000 0011:  AlwaysOn + Boost
64dec | 0100 0000:  TimerMode + Absence 
65dec | 0100 0001:  TimerMode + ECO Active
66dec | 0100 0010:  TimerMode + ECO Inactive
67dec | 0100 0011:  TimerMode + Boost
68dec | 0100 0100:  TimerMode + AUTO

Bit Number	Purpose/Function	Other Information
0 - 3	Operation Mode	Interpreted as integer, 0 == Absence, 1 == Eco Active, 2 == Eco Inoactive, 3 == Boost, 4 == Auto
4	?
5	?
6	TimerMode enabled
7	?

Temperature Values

Temperature values have an accuracy of a single decimal place. The two bytes are interpreted as an uint16 value and divided by 10:

float temperature = (float) (((int16_t) message[2] << 8) | message[1]) / 10.0;

Example Table:

184 1 = 44,0°C
194 1 = 45,0°C
204 1 = 46,0°C
214 1 = 47,0°C
224 1 = 48,0°C
234 1 = 49,0°C
244 1 = 50,0°C
254 1 = 51,0°C
8 2   = 52,0°C
18 2  = 53,0°C
28 2  = 54,0°C
38 2  = 55,0°C
48 2  = 56,0°C
58 2  = 57,0°C
68 2  = 58,0°C
78 2  = 59,0°C
88 2  = 60,0°C
98 2  = 61,0°C
108 2 = 62,0°C

Date Formula

    uint16_t year  = 2000 + (payload[19] / 2);
    uint8_t  month = (payload[18] >> 5) + ((payload[19] % 2) * 8);
    uint8_t  day   = payload[18] & 0x1F;

Example Table (Byte 19):

42dec = 2021 (First Half)	
43dec	= 2021	(Second Half)
44dec	= 2022	(First Half)
45dec	= 2022	(Second Half)
46dec	= 2023	(First Half)
47dec	= 2023	(Second Half)

Commands

Commands are executed by the HMI as soon as placeholder fields/values are replaced by command values. The HMI Controller awaits the change of the Main controller and then resets the placeholder fields to the previous placeholder value.

Change Capacity

Affected Byte Positions: 33, 34

Examples:

Noop: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
270l: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255  14   1
200l: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 200   0

Change PWM

Affected Byte Positions: 4, 24
Allowed Range 50-100%

Examples:

Noop:         35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
PWM 1 to 50:  35 18 2 65  60 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0  50 0 9 66 1 1 255 255 255 255 255
PWM 1 to 65:  35 18 2 65  60 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0  65 0 9 66 1 1 255 255 255 255 255
PWM 2 to 81:  35 18 2 65 124 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0  81 0 9 66 1 1 255 255 255 255 255
PWM 2 to 60:  35 18 2 65 124 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0  60 0 9 66 1 1 255 255 255 255 255
PWM 3 to 100: 35 18 2 65 188 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 100 0 9 66 1 1 255 255 255 255 255
PWM 3 to 66:  35 18 2 65 188 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0  66 0 9 66 1 1 255 255 255 255 255

Change Brand

Affected Byte Positions: 32
65dec = Atlantic
78dec = NoName
83dec = Sauter
84dec = Thermor

Noop:     35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Atlantic: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255  65 255 255
NoName:   35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255  78 255 255
Sauter:   35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255  83 255 255
Thermor:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255  84 255 255

Enable/Disable Heat-Exchanger

Affected Byte Positions: 8

Noop: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Yes:  35 18 2 65 252 0 240 32  16 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
No:   35 18 2 65 252 0 240 32   0 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255

Enable/Disable Communication

Affected Byte Positions: 6

Noop:         35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Not Disabled: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Disabled:     35 18 2 65 252 0 16  32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255

Enable/Disable Circulation

Affected Byte Positions: 14

Noop: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
No:   35 18 2 65 252 0 240 32 240 4 60 16 16 24 240 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Yes:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 241 255 0 x x x x x  0 0 255 0 9 66 1 1 255 255 255 255 255

Enable/Disable PV-Input

Affected Byte Positions: 14

Noop: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
No:   35 18 2 65 252 0 240 32 240 4 60 16 16 24  16 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Yes:  35 18 2 65 252 0 240 32 240 4 60 16 16 24  17 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255

Change Min Target Temperature

Affected Byte Positions: 16
Allowed Range 40-50°C

Noop:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
44°C:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 255  44 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
40°C:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 255  40 0 x x x x x  0 0 255 0 9 66 1 1 255 255 255 255 255

Enable/Disable Anti-Dry-Heating

Affected Byte Positions: 4

Noop:     35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Enabled:  35 18 2 65 128 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Disabled: 35 18 2 65 132 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255

Change Anti-Legionalle Target Temperature

Affected Byte Positions: 30
Range: 62-70°C

Examples:

Noop: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
62°C: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1  62 255 255 255 255
70°C: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1  70 255 255 255 255

Change Wattage of installed heat-element

Affected Byte Positions: 31
Range 1000 - 3000W
Value divided by 100

Noop:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
1000W: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255  10 255 255 255
1600W: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255  16 255 255 255
1700W: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255  17 255 255 255
3000W: 35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255  30 255 255 255

Clear Alarm / Clear Error

If an error occurred which is recoverable, the hmi offers the functionality to "stop the alarm". This will resume the operation of the heatpump and clears the error.

Affected Byte Position: 16

Noop:         35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 0  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255
Clear Alarm:  35 18 2 65 252 0 240 32 240 4 60 16 16 24 255 255 4  x x x x x 0 0 255 0 9 66 1 1 255 255 255 255 255

Request Error Message

Affected Byte Positions: 27 - 28
Triggers the main controller to emit a single message 74 (error message)
RequestId is incremented for each request, starting from zero, most likely with wrap around.
The error number addresses the list of errors, the most recent error is id==1
If an error number is addressed which is not existent, the main controller will respond with an empty error message ( zeroed)

Noop:                                     35 18 2 65 252 0 240 32 240 6 60 16 16 24 255 255 0 x x x x x 0 0 255 0 9 66 0  0 255 255 255 255 255
Request Error No 1 with Request Id: 76    35 18 2 65 252 0 240 32 240 6 60 16 16 24 255 255 0 x x x x x 0 0 255 0 9 66 1 76 255 255 255 255 255
Request Error No 2 with Request Id: 77    35 18 2 65 252 0 240 32 240 6 60 16 16 24 255 255 0 x x x x x 0 0 255 0 9 66 2 77 255 255 255 255 255

Send by the main controller

193

Byte Number	Example	Purpose/Function	Other Information
0	37	Length Field	-
1 - 2	235 1	Hot Water Temp.	Note: Range Allowed 18 - 62°C
3 - 4	121 0	Input Air Temp	Note: Range Allowed 10 - 27°C
5 - 6	94 0	Lower Evaporator Temp	Note: Range Allowed -2 - 41°C
7 - 8	102 0	Upper Evaporator Temp	Note: Range Allowed -3 - 39°C
9	0	?	-
10	0	?	-
11	0	?	-
12	0	?	-
13	1	?	-
14	100	Setting: PWM Level 3	Note: Range Allowed in HMI 50-100%, Adjustable from HMI controller
15	65	Setting: PWM Level 1	Note: Range Allowed in HMI 50-100%, Adjustable from HMI controller
16	81	Setting: PWM Level 2	Note: Range Allowed in HMI 50-100%, Adjustable from HMI controller
17	8 or 0	Picture Bitmask	See table below
18 - 19	0 0	Fan-Speed	Either 0 (off) or 650 (lowspeed) or 810 (highspeed) Maybe rpm? Does this reflect the PWM settings?
20	44	Setting: Min T Target	Adjustable from HMI controller
21	62	Setting: Anti-Legionella T Target	Adjustable from HMI controller
22	0	State: PV and Solar Input	16 == PV Enabled and Active, 32 == Solar Input Triggered
23	255	Error-Code	In Error State this contains Error Code, eg. 7
24	255	Error-Code	In Error State this contains 0
25	255	Error-Code	In Error State this contains 0
26	87	?	-
27	9	?	-
28	66	?	-
29	88	?	-
30	2	?	-
31	0	?	-
32	16	Setting: Wattage Heat-Element	Note: Multiplied by 100 -> 1600W, Adjustable from HMI controller
33 - 34	14 1	Setting: Boiler Capacity (l)	'14 1' == 270l, '200 0' == 200l, Adjustable from HMI controller
35	78	Setting: Brand	65 == Atlantic, 78 == NoName, 83 == Sauter, 84 == Thermor, Adjustable from HMI controller
36	21	Setting: Bitflags	See Table below, Adjustable from HMI controller

Byte No 17: Picture Bitmask

Findings...

0dec   | 0000 0000: Nothing Shown on HMI
8dec   | 0000 1000: Fan is turned on (observed via testmode)
9dec   | 0000 1001: Heating Element
10dec  | 0000 1010: Heatpump
11dec  | 0000 1011: Heatpump + Heating Element
14dec  | 0000 1110: Heatpump + Boiler Backup
15dec  | 0000 1111: Heatpump + Heating Element + Boiler Backup
32dec  | 0010 0000: Defrost
34dec  | 0010 0010: Defrost + Heatpump
40dec  | 0010 1000: Defrost + Fan
41dec  | 0010 1001: Defrost + Fan + Heating Element
64dec  | 0100 0000: Unknown, Observed while triggering Error 7
192dec | 1100 0000: Unknown, Observed while triggering Error 7

Bit Number	Purpose/Function	Other Information
0	Heating Element On/Off
1	Heatpump On/Off
2	Boiler Backup On/Off
3	Fan On/Off.
4	?
5	Defrost On/Off
6	?
7	?

Byte No 36: Settings Bitmask

Findings...

5dec  | 0000 0101: Communication Enabled, PV enabled, No Circulation, Anti-Dry-Heating
17dec | 0001 0001: Communication Enabled, PV disabled, Heat-Exchanger available, No Circulation, No Anti-Dry-Heating
20dec | 0001 0100: Communication Enabled, PV enabled, Heat Exchanger not available, No Circulation, No Anti-Dry-Heating
21dec | 0001 0101: Communication Enabled, PV enabled, No Circulation, No Anti-Dry-Heating
23dec | 0001 0111: Communication Enabled, PV enabled, With Circulation Enabled, No Anti-Dry-Heating
29dec | 0001 1101: Communication Disabled, PV enabled, Heat-Exchanger available, No Circulation, No Anti-Dry-Heating

Bit Number	Purpose/Function	Other Information
0	Heat-Exchanger Available
1	Circulation Enabled
2	PV Input Enabled	If flag is set, pv input is enabled
3	Communication Disabled	If flag is set, io-homecontrol/cozytouch is disabled
4	Anti-Dry-Heating Disabled	If flag is set, there is no Anti-Dry-Heating
5	? / Unused
6	? / Unused
7	? / Unused

67

Byte Number	Example	Purpose/Function	Other Information
0	31	Length Field	-
1 - 2	221 1	Power Consumption Heatpump	-
3 - 4	0 0	Power Consumption Heating Element	-
5	0	?	-
6	0	?	-
7 - 8	221 1	Power Consumption Total (Both)	-
9 - 10	54 215	Total Water Production (l)	Ticket
11 - 14	231 9 0 0	Total Operation Hours (Heatpump)	-
15 - 18	24 0 0 0	Total Operation Hours (Heating Element)	-
19 - 22	231 9 0 0	Total Operation Hours (Both)	-
23 - 30	127 37 19 0 0 0 0 0	Total Energy Counter (Wh)	-

74 Error Message

Error messages are emitted by the main controller if the HMI is requesting error messages.

Any change to byte 27 and byte 28 of the HMI (194) message will trigger a new error message.
The main controller is emitting empty error messages if HMI is requesting placeholder values (errorNumber==0, requestId==0) or if an invalid errorNumber has been requested.
Entering Secret Diagnosis Menu: HMI will fetch all existing errors
The HMI controller will request an error message if the error bitflag (within main message, byte 17) has been set.
The MAIN controller will never emit an error message, without an HMI controller asking for it.
ErrorID == 0 is reserved and always contains an empty error message if requested.

Byte Number	Example	Purpose/Function	Other Information
0	35	Length Field	-
1	3	Request-Id	Matches original request from HMI
2	7	Error-Code	-
3	0	?	-
4 - 5	62 2	Water-Temperature	-
6 - 7	213 0	Air-Temperature	-
8 - 9	212 0	Upper Evaporator	-
10 - 11	206 0	Lower Evaporator	-
12	0	?	-
13	0	?	-
14	0	?	-
15	0	?	-
16	0	State Flags	6 == HeatPump Active + Fan (?)
17	0	?	-
18	0	?	-
19	0	?	-
20	0	?	-
21	0	Fan-Speed PWM	-
22	0	?	-
23	0	?	-
24	0	?	-
25	252	Runtime Heat-Element	-
26	0	Runtime Heat-Element	-
27	146	Runtime Heat-Pump	-
28	19	Runtime Heat-Pump	-
29	185	Date	-
30	48	Date	-
31	29	Time: Minutes	-
32	21	Time: Hours	-
33	1	Operation Mode	0 == Absence, 1 == Eco/Manuell EC ...
34	4	?	-

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PROTOCOL.md

PROTOCOL.md

Protocol

General

Wiring

Overview

Message Format

Identifier

Checksum

Messages

Send from the HMI controller

194

Byte No. 3: Operation Mode

Temperature Values

Date Formula

Commands

Change Capacity

Change PWM

Change Brand

Enable/Disable Heat-Exchanger

Enable/Disable Communication

Enable/Disable Circulation

Enable/Disable PV-Input

Change Min Target Temperature

Enable/Disable Anti-Dry-Heating

Change Anti-Legionalle Target Temperature

Change Wattage of installed heat-element

Clear Alarm / Clear Error

Request Error Message

Send by the main controller

193

Byte No 17: Picture Bitmask

Byte No 36: Settings Bitmask

67

74 Error Message

Files

PROTOCOL.md

Latest commit

History

PROTOCOL.md

File metadata and controls

Protocol

General

Wiring

Overview

Message Format

Identifier

Checksum

Messages

Send from the HMI controller

194

Byte No. 3: Operation Mode

Temperature Values

Date Formula

Commands

Change Capacity

Change PWM

Change Brand

Enable/Disable Heat-Exchanger

Enable/Disable Communication

Enable/Disable Circulation

Enable/Disable PV-Input

Change Min Target Temperature

Enable/Disable Anti-Dry-Heating

Change Anti-Legionalle Target Temperature

Change Wattage of installed heat-element

Clear Alarm / Clear Error

Request Error Message

Send by the main controller

193

Byte No 17: Picture Bitmask

Byte No 36: Settings Bitmask

67

74 Error Message