DomBus32 is a DIN-RAIL module, 54mm wide, with 3 relay outputs, 3 AC inputs and 5 low-voltage I/Os.
AVAILABLE IN TWO VERSIONS: DomBus protocol and Modbus protocol!

The English language page contains the updated information

To simplify wiring, the terminal block has 3 terminals for relays, 3 for AC inputs, and 1 common terminal (to be connected to Neutral or Line): in this way it's easier and faster to connect the module to electrical loads sharing the same circuit breaker (e.g. light system, heating system valves, ...). Please take care to connect only loads that are protected by the same RCCB (circuit breaker).  Of course it's possible to use relays to switch low voltage loads or select the working mode of a machine (heat pump, for example), connecting the common line to GND or DC supply voltage: in this case the 3 AC inputs are useless.

As other DomBus modules, all ports can be configured in many different ways, and also this module supports DCMD, commands sent to the same or other DomBus modules to perform simple actions, that permit to achieve high reliability (DCMD commands work even if domotic controller is not operational) and easy programming (don't need to create automations in the home automation controller: just configure DomBus ports to perform actions on events). DCMD also permits to activate a Domoticz group or scene when an event occurr, for example a pushbutton switch has been pushed (pulse 500ms, pulse 1s, pulse 2s, pulse 4s), a sensor reached a value, ...

Last, but not least, as other DomBus modules, DomBus32 is optimized to get low power consumption, less than 10mW normally (0.75mA @13.6V) and less than 150mW when all 3 relays are ON (10mA @13.6V).

It's available with two firmware types: DomBus (proprietary protocol with enhanced features) for Domoticz controller, and Modbus RTU (standard protocol working with almost any home automation system). Check below for a detailed comparison between the two protocols.
It uses a RS485 industrial-grade serial bus, using a common shielded cable with 4 wires: 2 for 12/24V power supply, and 2 for data at 115200bps 8,n,1 (or other speed/parity in case of Modbus RTU).

It supports two different protocols (at puchase time, select the needed protocol!):

• DomBus protocol, that is supported by Domoticz home automation controller, is a reliable multi-master protocol that permits to manage dozens of modules and get status from a module as soon as it changes. Also it includes the so-called DCMD commands that, similarly to KNX, are transmitted between DomBus modules in the same bus to activate outputs, scenes and groups in case of events without needing for the intervention of the home automation controller, useful solution to get a home automation system working even in case of domotic controller fault. Check below for an explanation about DCMD.
  The Creasol DomBus plugin have to be installed in Domoticz, using the Python Plugin Manager or downloading the software from GitHub (see the section below).
• Modbus RTU protocol, widely used in industrial and home automation systems, is supported by almost any domotic controller like Home Assistant, OpenHAB, IObroker, Node-RED, ...
  Modbus is a master-slave protocol that permits to activate and deactivate a single relay or a group of relays by a single command. Also, it's possible to specify, for each relay, the ON time from 31.5ms to 1500 days, so the relay automatically switches OFF after the selected time.

Confused about the two versions? If you use Domoticz, DomBus version is much better because includes enhanced features like DCMD and devices autodiscovery.  For other building automations, Modbus version should be chosen because compatible with almost everything.
Ask for support on Telegram group https://t.me/DomBus

The RS485 serial bus is the ideal solution to get:

• easy wiring and connection: use a common thin alarm cable within 4 wires, 2x0.5mm² wires for 12V power supply, and 2x0.22mm² wires for data. This is much easier and better than ethernet UTP/STP connections.
• robustness differential signalling permits to connect about 30 modules with more than 200m total distance. Modules can be connected together using a mix of linear/star bus topology.
• very low power consumption: each module is supplied at 12V and has inside an high efficiency switching mode converter to minimize the power comsumption.
• power outage tolerant: using a 13.6V power supply with lead acid battery it's possible to supply domotic network, IPCams, NVR, switches, routers, so the system keeps working even in case of power cut-out.
• no RF pollution, no batteries to change
  

For large building, to improve the bus reliability, it's possible to make more than 1 bus so in case of fault, only the bus with fault stops working.

Features

• 3 relay outputs, 250Vac 5A max, with overvoltage protection (varistors)
• 3 AC inputs, 110-230V, to monitor voltage on loads
• 1 common terminal block (for Neutral, Line or common voltage), to simplify connections
• 5 programmable low-voltage I/Os
• DCMD supports (DomBus firmware only): this is a feature (described below) that permits to get easy automations without writing a line of code, and command exchanged between DomBus modules even in case that domotic controller is stopped. For example configuring a pushbutton input port as
  DCMD(Pulse)=11.3:Toggle, DCMD(Pulse1)=0.7:Toggle, DCMD(Pulse2)=0.8:On
  it's possible:
  * with a short 0.5s pulse, toggles on/off port #3 output of DomBus module #11
  * with a 1s pulse, toggle on/off a group of switches on the controller
  * with a 2s long pulse, activate a scene that, for example, disable all lights/loads and activate the alarm system (useful when leaving the building).
• 8-25Vdc power supply
• 10mW power consumption, 150mW max power consumption with all relays ON
• 53x89x65mm

Applications

• Turn on/off up to 3 lights or other loads
• Check that appliances are supplied (e.g. check that Heat Pump is correctly supplied during the winter, to prevent that idraulic circuit breaks during the Winter when temperature falls below 0°C)
• Turn on/off heating system valves
• Connect external pushbutton switches, switches, double pushbuttons, S0 counters, ....
• Connect up to 5 PIRs, magnetic contact sensors, or other low voltage devices.
• Interface up to 3 PIRs with 230V output to enable external lights and start recording (NVR or DVR)
• ....

Warnings

• Do not mix high voltage (230V) loads and low voltage (5/12/24V) loads on the same terminal block!
• Use a 4 wires shielded cable for the bus   (common alarm cable, 2x0.5mm² + 2x0.22mm²), using two lines to feed  power supply (12 or 24Vdc) protected by a fuse.
• To reduce noise and reflections on the bus, enable the termination resistor (shorting Rbus PCB jumper) on the two furthest ends of the bus.

DomBus32 Ports capabilities

Default address: 0xff32

Application Note: existing light system

The following schema shows how to manage an existing light system, using step-relay, with DomBus32.

With DomBus32 is very easy to manage step-relay and control the light from Domoticz (using DomBus firmware) or other home automation systems (Home Assistant, OpenHAB, ioBroker, ... using DomBus32 with Modbus firmware).

Each light is connected to an opto-isolated input, to monitor its state and display it on the smartphone/tablet/PC. Each existing pushbutton is also connected to the DomBus32 relay.

If a light is ON, just click on the light symbol to switch it OFF (or vice versa): DomBus32 module wil send a short pulse to the existing step-relay to switch the light OFF (or ON).

Through the home automation controller it will be very easy to set a scene to switch all lights ON or OFF (useful when leaving the house).

DomBus modules installation block chart

• Use a 12V power supply unit with backup battery charger, to avoid trouble on RaspberryPI or other devices. Also, in this way it's possible to get everything working even in case of power outage (domotic controller, domotic modules, network switches, routers, NVR and IPcams).
• Use a 12V lead-acid battery well dimensioned to supply everything during blackout.
• Use a DC/DC converter 12V → 5V 3A to supply the RaspberryPI, if you have it.
• To use DomBus modules, use a standard alarm shielded cable (within 4 wires) to interconnect all modules to RaspberryPI (through a cheap RS485 to USB adapter).
• Protect each bus with a fuse

Ports parameters

DCMD commands

This is an experimental function, undergoing testing and development, available on all DomBus modules, expept DomBus1

For each port it's possible to configure, through the Domoticz Description field, one or more DCMD commands.

DCMD is a command that is sent to the module itself or to another DomBus module, in response to an event, and more DCMD commands can be specified for the same event and port.

Also it's possible to send DCMD command to the domotica controller to activate, deactivate or toggle a scene/group; to get this feature please assure that:

• 127.0.0.1 was added to Domoticz → Setup → Settings → Trusted Networks field
• if Domoticz www port is different from 8080, manually replace 8080 with the used port in the plugins/CreasolDomBus/CreasolDomBusProtocol.py file:
  JSONURL = "http://127.0.0.1:8080/json.htm"

The syntax is DCMD(Event:ValueLow:ValueHigh)=ModuleAddress.ModulePort:Command:Value

where ValueLow, ValueHigh, Value are optional parameters.
When ModuleAddress corresponds to the same module that we're editing, the command is executed locally, by the same module.
When ModuleAddress corresponds to another Dombus module, the command is sent by bus to that module. When ModuleAddress is 0, the command is sent to the controller to activate the scene/group with idx=ModulePort : please note that ModulePort should be in hex format, so if ModulePort=11 the scene/group with idx=17 will be activated.

Example 1: configure a pushbutton switch to have 3 functions

IN_DIGITAL,INVERTED,
DCMD(Pulse)=0101.1:TOGGLE,
DCMD(Pulse1)=0101.2:ON:30m,
DCMD(Pulse2)=0101.2:OFF

Example 2: configure a pushbutton switch to trigger 2 scenes/groups

IN_DIGITAL,INVERTED,
DCMD(Pulse)=0.1:Toggle,
DCMD(Pulse2)=0.2:On

Example 3: temperature sensor that enable/disable electric heater and valve

In the description field of the temperature sensor we'll write

DCMD(Value:0:20.5)=0101.3:ON, (if temperature between 0 and 20.5°C, turns ON heater on output 3 of module 0x0101)
DCMD(Value:0:20.5)=0102.1:ON, (if temperature between 0 and 20.5°C, turns ON valve output 1 of module 0x0102)
DCMD(Value:20.8:50)=0101.3:OFF (turn OFF heater when temperature above 20.8°C)
DCMD(Value:20.8:50)=0102.1:OFF (turn OFF valve when temperature above 20.8°C)
Domoticz temperature sensor Description will be:

TEMPERATURE,
DCMD(Value:0:20.5)=0101.3:ON,
DCMD(Value:0:20.5)=0102.1:ON,
DCMD(Value:20.8:50)=0101.3:OFF,
DCMD(Value:20.8:50)=0102.1:OFF

Installation

Using RS485 specific cables it's possible to get almost 1km linear bus with several devices attached. Alternatively, it's possible to use 2 twisted pairs of cheap Cat6 UTP or STP cable, one twisted pair for data (A and B) and one for 12-24V power supply. Ideally, all devices should be connected using a linear bus topology, to get the lowest reflection/noise, and connect 100-150 Ohm resistor on the two ends, as illustrated in the Fig. 2. In practice, this is not important for common buildings.

At Raspberry/PC side, it's possible to use a cheap USB-RS485 adapter, if a serial port with RS485 driver is not already available.

Using DomBus modules it's possible to:

1. avoid RF pollution
2. no need to periodically change batteries on sensors/actuators
3. using a UPS or  13.6V power supply with backup battery, it's possible to get a building automation system that works also in case of power outage
4. very very low power consumption

Writing a microSD card with a fresh Raspbian + Domoticz distribution

Click here if you need to write a microSD card with a clean updated Raspbian+Domoticz image optimized to extend SD life (minimizing writings), and with some addons (firewall, backup, libraries).

Adding DomBus plugin to Domoticz

Linux version

This procedure is not needed in case of a new Domoticz installation writing the SD as written above.
If Domoticz does not already include the DomBus plugin, type the following commands (from Linux root shell: type sudo su - to become root):

#install git, if not already installed
which git
if [ $? -ne 0 ]; then sudo apt install git; fi

#change to the domoticz directory / plugins
cd /home/pi/domoticz/plugins 

#fetch the Python Plugin Manager (that can be used to install/upgrade other plugins, including Creasol DomBus)
git clone https://github.com/ycahome/pp-manager

#fetch Creasol Plugin
git clone https://github.com/CreasolTech/CreasolDomBus

#restart Domoticz daemon
service domoticz restart

Windows version

Domoticz configuration

After plugins installation and Domoticz restart, it's possible to add the Creasol DomBus hardware (Setup->Hardware , add new "dombus" hardware type "Creasol DomBus" and specify the serial device, normally /dev/ttyUSB0) and connect the DomBus device to the RS485 bus.
DomBus module is factory programmed with a default address indicated above, and only one port will be automatically added to the Switches panel of Domoticz. Enter the Switches panel, find the new device with the DomBus default address, click on Edit and add in the description ,HWADDR=0x0001 to set the new address to 0001, or specify another address of your choice. Reload the Switches panel to see all input/output/led ports of DomBusTH active.

With Domoticz, each DomBus port can be configured via the Domoticz device description: for example a port IN_DIGITAL normally is On when it's left unconnected, and Off when it's shorted to GND, but it's possible to invert this function specifying in the device description the parameter INVERTED, separated by a comma (,): IN_DIGITAL,INVERTED . Relay outputs can be configured writing in the description field OUT_DIGITAL or OUT_RELAY_LP: in the latter case, relay are internally managed to assure a low power consumption.
Please check the sections Ports capabilities and Ports parameters.

Ports that are not used can be disabled in Domoticz Setup → Devices clicking on the blue arrow of each useless port (device), but in case of a bus with almost 255 ports, it's suggested to disable the unused ports by using the DISABLE command:
1. suppose that DomBus module 0x0001 has ports 3,4,5,6,8 not used
2. in Domoticz Switches panel select port1 of that module ([0001.1] RL1)
3. click on Edit, and add in the Description field DISABLE=3:4:5:6:8 and click on Save.
In this way, the selected ports will be disabled and removed from the Devices list. With this solution it's possible to add more DomBus modules to the same bus, with up to 255 enabled ports. In large buildings, it's a good practice to have more than one bus, to divide floors or areas.

Updating DomBus plugin on Domoticz

1. Go to Setup → Hardware → PP-Manager (name of the python plugin manager)
2. Assure the PP-Manager is enabled
3. Pluging to install: select Creasol DomBus
4. Auto Update: choose Selected
5. Click on Update button

Linux platform, with DomBus plugin installed manually

cd DOMOTICZ_HOME/plugins (e.g. cd /home/pi/domoticz/plugins)
git clone https://github.com/CreasolTech/CreasolDomBus.git

Linux platform, with DomBus plugin installed using git

cd DOMOTICZ_HOME/plugins/creasolDomBus (e.g. cd /home/pi/domoticz/plugins/CreasolDomBus)
git pull

Windows platform

Files should be downloaded from the github repository https://github.com/CreasolTech/CreasolDomBus by using git program or www browser, then placed in the DOMOTICZ_HOME/plugin/CreasolDomBus directory

Installing CreasolDomBus Home Assistant custom component

cd /tmp
git clone https://github.com/CreasolTech/home-assistant-creasol-dombus.git
cp -a home-assistant-creasol-dombus/custom_components HADIR/config/
ha core restart

FAQ about DomBus products

• Some modules are available with both DomBus and Modbus protocol firmwares, so the best one for your needs should be chosen. Below in the FAQ some information about the two protocols
• You can connect up to 20-30 modules per bus: the max number of ports managed by Domoticz is 256, and you can use the DISABLE command to disable ports that are not used in case that 256 ports are not enough.
• It's good to make different buses on large buildings with several sensors and actuators, for example a bus for the ground floor, one for the second floor, ... Any bus is connected to a RS485 port/adaptor and need a DomBus plugin for that serial port, so in the Domoticz Setup→Hardware, one Creasol DomBus line for each serial port.
• DomBus modules are factory programmed with a certain address, for example 0xff12 for DomBus12, 0xff23 for DomBus23, and so on. As each device connected to the bus MUST have a unique address, add only one module to the bus then program its address using the command HWADDR=0x0001, then connect another DomBus module and program its address to 0x0002 and so on. Address can be chosen to identify floor and room, for example 0x1023 to identify floor 1, room 2, module 3 in that room.

How can I change address of DomBusTH device?

DomBusTH: how to mount and fix it?

DomBusTH: how to do a factory reset?

Why buzzer does not work?

2 or more modules with the same address

How many DomBus modules can I connect to a bus?

How to split a bus in 2 buses in Domoticz?

How to identify a RS485/USB adapter when more than one are connected

All DomBus devices have been duplicated!

I have many USB-serial adapters

Why there is a long delay between pushing a button and get light/output on?

Why DomBus device does not work?

One DomBus module stopped working

Why current consumption is 0uA?

How to add icons on smartphone to turn On/Off lights/loads, or enable/disable scenes/groups?

How to send Telegram notification from a lua script in Domoticz?

-- script_time_example.lua  : simple example script that write a message to Telegram channel/group if temperature is less than 5
commandArray={}
dofile "script/lua/globalvariables.lua" -- read a file with some variables, including Telegram API key and ChatID
dofile "script/lua/globalfunctions.lua" -- read a file with some functions
if (tonumber(otherdevices['Temp_outdoor']) < 5) then
	telegramNotify("Low temperature: bring flowers inside")	-- send message by Telegram
end
return commandArray

2022-11-04 Rev02g4

2022-10-22 Rev02g3

2022-09-26 Rev02g

2022-02-07

2021-12-02

2021-10-25

2021-10-19

2021-03-16

2020-12-28

Need help? join the DomBus channel on Telegram!
Esiste anche il Canale Telegram in Italiano DomBus_it!