EMS-ESP32/docs/SM100.md

General

The SM100 (and SM200) is a device to enhance Buderus heatings with the ability to earn solar energy using solar collectors and spend these energy into a water reservoir. There are different scenarios available to add these module into a heating.

Protocol: The SM100 device communicates using the EMS+ protocol. That means it sends and interprets EMS and also EMS+ messages.

External Link to the german product page of SM100: https://www.buderus.de/de/produkte/catalogue/alle-produkte/7607_solarmodul-logamatic-sm100

The following reverse protocol engineering based on a Buderus GB172 heating combined with a water reservoir in one heating circuit. Other combinations, configurations and protocol types are not covered.

Also refer to https://github.com/proddy/EMS-ESP/issues/267 for the SM200

Decoded EMS+ Messages

How to interpret the tables below. Take an example telegram:

       EMS+ telegram type
          ->|   |<-
30 00 FF 00 02 62 01 FB 01 9E 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 2B
   data block --> 00 01 02 03 04 06 07 08 09 0A...
                  ^
                  | 
             start of data

The data starts at the 7th byte straight after the typeID - here x0262. Position 0 is the first byte of the data block.

Telegram overview

EMS+ telegram type	description	schedule	number of data bytes in decimal
x0262	Temperatures	every minute	26 (max. 24 in one telegram)
x0263	unknown	every minute	12
x0264	Solar pump modulation	every minute	17
x0266	unknown	every minute	04
x0268	unknown	every minute	02
x026A	Solar pump on/off	every minute	12
x028E	Solar energy earnings	every hour	15

Telegram details

Telegram type	data position (0..n) in decimal	description	format
x0262	0+1	T1 - Temperature of solar collector [°C]	2 bytes
x0262	2+3	T2 - Temperature of bottom water reservoir 1 [°C]	2 bytes
x0262	16+17	T5 - Temperature of bottom water reservoir 2 [°C]	2 bytes
x0264	9	Solar pump modulation [%]	1 byte
x026A	10	PS1 - Solar pump: on=04 and off=03	1 byte
x026A	4	VS2 - Cylinder select value: cyl#2=04 and cyl#1=03	1 byte
x028E	2+3	Solar energy earning last hour /10 [Wh]	2 byte
x028E	6+7	Solar energy earning today [Wh]	2 byte
x028E	10+11	Solar energy earning total /10 [kWh]	2 byte

Examples

Solar pump status and changes:

1.Status solar pump is currently off: see x026A data byte 0A "03" and x0264 data byte 9 "00"

 SM -> all, type 0x026A telegram: 30 00 FF 00 02 6A 03 03 03 00 03 03 03 03 03 00 03 03 (CRC=E5), #data=11
 SM -> all, type 0x0264 telegram: 30 00 FF 00 02 64 00 00 00 04 00 00 FF 00 00 00 0C 0A 64 00 00 00 00 (CRC=53), #data=16

2.Status pump is currently on: see x026A data byte 0A "04" and x0264 data byte 9 "1E"

 SM -> all, type 0x026A telegram: 30 00 FF 00 02 6A 03 03 03 00 03 03 03 03 03 00 04 03 (CRC=EB), #data=11
 SM -> all, type 0x0264 telegram: 30 00 FF 00 02 64 00 00 00 04 00 00 FF 00 00 1E 09 08 64 00 00 00 00 (CRC=CD), #data=16

3.Solar pump changes from off --> on: see x0264 data byte 9 set at first to "64" and x026A byte 0A is set to "04"

 SM -> all, type 0x0264 telegram: 30 00 FF 09 02 64 64 (CRC=37)
 SM -> all, type 0x026A telegram: 30 00 FF 0A 02 6A 04 (CRC=53)

Less then 10 seconds later the pump is throttled to `30%` 0x1E

 SM -> all, type 0x0264 telegram: 30 00 FF 09 02 64 1E (CRC=4D)

4.Solar pump changes from on --> off: see x0264 data byte 9 set to "00" and x026a byte 0A is set to "03"

 SM -> all, type 0x0264 telegram: 30 00 FF 09 02 64 00 (CRC=53)
 SM -> all, type 0x026A telegram: 30 00 FF 0A 02 6A 03 (CRC=54)

Solar energy earnings:

 SM -> all, type 0x028E telegram: 30 00 FF 00 02 8E 00 00 0C F3 00 00 06 02 00 00 76 33 (CRC=8A), #data=11

MQTT message format

Example of MQTT message:

{"collectortemp":54.8,"bottomtemp":38.8,"pumpmodulation":30,"pump":"on","energylasthour":136.5,"energytoday":447,"energytotal":3029.4}

Please note that not all json elements are available after a restart of the ESP! It takes several minutes (up to 1 h) to collect all necessary values

Home Assistant integration

Example to integrate values into Home Assistant

binary_sensors.yaml:

- platform: mqtt
  name: 'Solar Pump'
  state_topic: 'home/ems-esp/sm_data'
  value_template: '{{ value_json.pump }}'
  payload_on: "on"
  payload_off: "off"
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"

sensors.yaml:

- platform: mqtt
  state_topic: 'home/ems-esp/sm_data'
  name: 'Collector Temperature'
  unit_of_measurement: '°C'
  value_template: '{{ value_json.collectortemp }}'
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"

- platform: mqtt
  state_topic: 'home/ems-esp/sm_data'
  name: 'Bottom Temperature'
  unit_of_measurement: '°C'
  value_template: '{{ value_json.bottomtemp }}'
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"

- platform: mqtt
  state_topic: 'home/ems-esp/sm_data'
  name: 'Solar Pump modulation'
  unit_of_measurement: '%'
  value_template: '{{ value_json.pumpmodulation }}'
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"

- platform: mqtt
  state_topic: 'home/ems-esp/sm_data'
  name: 'Solar Energy Last Hour'
  unit_of_measurement: 'Wh'
  value_template: '{{ value_json.energylasthour }}'
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"

- platform: mqtt
  state_topic: 'home/ems-esp/sm_data'
  name: 'Solar Energy Today'
  unit_of_measurement: 'Wh'
  value_template: '{{ value_json.energytoday }}'
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"

- platform: mqtt
  state_topic: 'home/ems-esp/sm_data'
  name: 'Solar Energy Total'
  unit_of_measurement: 'kWh'
  value_template: '{{ value_json.energytotal }}'
  qos: 1
  payload_available: "online"
  payload_not_available: "offline"