openHAB

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# KNX Binding

The openHAB KNX binding allows to connect to KNX Home Automation (opens new window) installations. Switching lights on and off, activating your roller shutters, or changing room temperatures are only some examples.

To access your KNX bus, you either need a gateway device which is connected to the KNX bus and allows computers to access the bus communication. This can be either an Ethernet (as a Router or a Tunnel type) or a serial gateway. The KNX binding then can communicate directly with this gateway. Alternatively, a PC running KNXD (opens new window) (free open source component software) can be put in between which then acts as a broker allowing multiple client to connect to the same gateway. Since the protocol is identical, the KNX binding can also communicate with it transparently.

Attention: With the introduction of Unit of Measurement (UoM) support, some data types have changed (see number channel below):

  • Data type for DPT 5.001 (Percent 8bit, 0 -> 100%) has changed from PercentType to QuantityTypefor number channels (dimmer, color, rollershutter channels stay with PercentType).
  • Data type for DPT 5.004 (Percent 8bit, 0 -> 255%) has changed from PercentType to QuantityType.
  • Data type for DPT 6.001 (Percent 8bit -128 -> 127%) has changed from PercentType to QuantityType.
  • Data type for DPT 9.007 (Humidity) has changed from PercentType to QuantityType.

Rules that check for or compare states and transformations that expect a raw value might need adjustments. If you run into trouble with that and need some time, you can disable UoM support on binding level via the disableUoM parameter. UoM are enabled by default and need to be disabled manually. A new setting is activated immediately without restart.

# Supported Things

The KNX binding supports two types of bridges, and one type of things to access the KNX bus. There is an ip bridge to connect to KNX IP Gateways, and a serial bridge for connection over a serial port to a host-attached gateway.

# Bridges

The following two bridge types are supported. Bridges don't have channels on their own.

# Discovery

KNX IP bridges, i.e. IP interfaces, routers, and knxd instances, are discovered through mulitcast communication in the local network. As a KNX setup is typically static, this in only done during startup of the binding. Corresponding bridges are added to the inbox. Additional configuration might be necessary after adding a bridge.

Note that several items per device might be created, as routers typically support routing and tunneling. Make sure you import only one item per device.

Discovery is not available for serial bridges and device Things described below. Discovery of IP bridges will not work without further measures if openHAB and the interface run on different network segments, as multicast traffic is typically not forwarded.

# IP Gateway

The IP Gateway is the most commonly used way to connect to the KNX bus. At its base, the ip bridge accepts the following configuration parameters:

Name Required Description Default value
type Yes The IP connection type for connecting to the KNX bus (TUNNEL, ROUTER, SECURETUNNEL or SECUREROUTER) -
ipAddress for TUNNEL Network address of the KNX/IP gateway. If type ROUTER is set, the IPv4 Multicast Address can be set. for TUNNEL: <nothing>, for ROUTER: 224.0.23.12
portNumber for TUNNEL Port number of the KNX/IP gateway 3671
localIp No Network address of the local host to be used to set up the connection to the KNX/IP gateway the system-wide configured primary interface address
localSourceAddr No The (virtual) individual address for identification of this openHAB Thing within the KNX bus

Note: Use a free address, not the one of the interface. Or leave it at 0.0.0 and let openHAB decide which address to use. When using knxd, make sure not to use one of the addresses reserved for tunneling clients.		 0.0.0
useNAT No Whether there is network address translation between the server and the gateway false
readingPause No Time in milliseconds of how long should be paused between two read requests to the bus during initialization 50
responseTimeout No Timeout in seconds to wait for a response from the KNX bus 10
readRetriesLimit No Limits the read retries while initialization from the KNX bus 3
autoReconnectPeriod No Seconds between connect retries when KNX link has been lost (0 means never). 0
routerBackboneKey No KNX secure: Backbone key for secure router mode -
tunnelUserId No KNX secure: Tunnel user id for secure tunnel mode (if specified, it must be a number >0) -
tunnelUserPassword No KNX secure: Tunnel user key for secure tunnel mode -
tunnelDeviceAuthentication No KNX secure: Tunnel device authentication for secure tunnel mode -

# Serial Gateway

The serial bridge accepts the following configuration parameters:

Name Required Description Default value
serialPort Y The serial port to use for connecting to the KNX bus -
readingPause N Time in milliseconds of how long should be paused between two read requests to the bus during initialization 50
responseTimeout N Timeout in seconds to wait for a response from the KNX bus 10
readRetriesLimit N Limits the read retries while initialization from the KNX bus 3
autoReconnectPeriod N Seconds between connect retries when KNX link has been lost, 0 means never retry 0
useCemi N Use newer CEMI message format, useful for newer devices like KNX RF sticks, kBerry, etc. false

# Things

# device Things

basic Things are wrappers around arbitrary group addresses on the KNX bus. They have no specific function in the KNX binding, except that if the address is defined, the binding will actively poll the Individual Address on the KNX bus to detect that the KNX actuator is reachable. Under normal real-world circumstances, either all devices on a bus are reachable, or the entire bus is down. If line couplers are installed, physical device addressing might be filtered; in this case please do not specify the addresses for devices on this line. When fetch is set to true, the binding will read-out the memory of the KNX actuator in order to detect configuration data and so forth. This is however an experimental feature, very prone to the actual on the KNX bus.

Name Required Description Default value
address N The individual device address (in 0.0.0 notation) -
fetch N Read out the device parameters and address/communication object tables (requires the address) false
pingInterval N Interval (in seconds) to contact the device and set the thing status based on the result (requires the address) 600
readInterval N Interval (in seconds) to actively request reading of values from the bus (0 if they should only be read once at startup) 0

Different kinds of channels are defined and can be used to group together Group Addresses. All channels of a device share one configuration parameter defined on device level: readInterval, an optional parameter which indicates if 'readable' group addresses of that Channel should be read periodically at the given interval, in seconds. 'Readable' group addresses are marked with an < in the group address definition of a Channel, see below. All readable group addresses are queried by openHAB during startup. If readInterval is not specified or set to 0, no further periodic reading will be triggered (default: 0).

# Channel Types

Standard channels are used most of the time. They are used in the common case where the physical state is owned by a device within the KNX bus, e.g. by a switch actuator who "knows" whether the light is turned on or off, or by a temperature sensor which reports the room temperature regularly.

Control channel types (suffix -control) are used for cases where the KNX bus does not own the physical state of a device. This could be the case if e.g. a lamp from another binding should be controlled by a KNX wall switch. When a GroupValueRead telegram is sent from the KNX bus to a *-control Channel, the bridge responds with a GroupValueResponse telegram to the KNX bus.

# Channel Type color, color-control
Parameter Description Default DPT
hsb Group address for the color 232.600
switch Group address for the binary switch 1.001
position Group address brightness 5.001
increaseDecrease Group address for relative brightness 3.007

The hsb address supports DPT 242.600 and 251.600.

Some RGB/RGBW products (e.g. MDT) support HSB values for DPT 232.600 instead of RGB. This is supported as "vendor-specific DPT" with a value of 232.60000.

# Channel Type contact, contact-control
Parameter Description Default DPT
ga Group address 1.009

Attention: Due to a bug in the original implementation, the states for DPT 1.009 are inverted (i.e. 1 is mapped to OPEN instead of CLOSE). A change would break all existing installations and is therefore not implemented.

# Channel Type datetime, datetime-control
Parameter Description Default DPT
ga Group address 19.001
# Channel Type dimmer, dimmer-control
Parameter Description Default DPT
switch Group address for the binary switch 1.001
position Group address of the absolute position 5.001
increaseDecrease Group address for relative movement 3.007
# Channel Type number, number-control
Parameter Description Default DPT
ga Group address 9.001

Note: The number channel has full support for Units Of Measurement (UoM).

Using the UoM feature of openHAB (QuantityType) requires that the DPT value is set correctly. Automatic type conversion will be applied if required.

Incoming values from the KNX bus are converted to values with units (e.g. 23 °C). If the channel is linked to the correct item-type (Number:Temperature in this case) the display unit can be controlled by item metadata (e.g. %.1f °F for 1 digit of precision in Fahrenheit). The unit is stripped if the channel is linked to a plain number item (type Number).

Outgoing values with unit are first converted to the unit associated with the DPT (e.g. a value of 10 °F is converted to -8.33 °C if the channel has DPT 9.001). Values from plain number channels are sent as-is (without any conversion).

# Channel Type rollershutter, rollershutter-control
Parameter Description Default DPT
upDown Group address for relative movement 1.008
stopMove Group address for stopping 1.010
position Group address for the absolute position 5.001
# Channel Type string, string-control
Parameter Description Default DPT
ga Group address 16.001
# Channel Type switch, switch-control
Parameter Description Default DPT
ga Group address for the binary switch 1.001

# Control Channel Types

In contrast to the standard channels above, the control channel types are used for cases where the KNX bus does not own the physical state of a device. This could for example be the case if a lamp from another binding should be controlled by a KNX wall switch. When a GroupValueRead telegram is sent from the KNX bus to a *-control Channel, the bridge responds with a GroupValueResponse telegram to the KNX bus.

# Channel Type "switch-control"
Parameter Description Default DPT
ga Group address for the binary switch 1.001
# Channel Type "dimmer-control"
Parameter Description Default DPT
switch Group address for the binary switch 1.001
position Group address of the absolute position 5.001
increaseDecrease Group address for relative movement 3.007
frequency Increase/Decrease frequency in milliseconds in case the binding should handle that (0 if the KNX device sends the commands repeatedly itself) 0
# Channel Type "rollershutter-control"
Parameter Description Default DPT
upDown Group address for relative movement 1.008
stopMove Group address for stopping 1.010
position Group address for the absolute position 5.001
# Channel Type "contact-control"
Parameter Description Default DPT
ga Group address 1.009

Attention: Due to a bug in the original implementation, the states for DPT 1.009 are inverted (i.e. 1 is mapped to OPEN instead of CLOSE). A change would break all existing installations and is therefore not implemented.

# Channel Type "number-control"
Parameter Description Default DPT
ga Group address 9.001

For UoM support see the explanations of the number channel.

# Channel Type "string-control"
Parameter Description Default DPT
ga Group address 16.001
# Channel Type "datetime-control"
Parameter Description Default DPT
ga Group address 19.001

# Group Address Notation

<config>="[<dpt>:][<|>]<mainGA>[[+[<]<listeningGA>][+[<]<listeningGA>..]]"

where parts in brackets [] denote optional information.

Each configuration parameter has a mainGA where commands are written to and optionally several listeningGAs.

mainGA also listens to incoming packets, unless prefixed with a > character. This is recommended if you have a dedicated status group address which is added as listeningGA.

The optional < sign tells whether the group address of the datapoint accepts read requests on the KNX bus (it does, if the sign is there). The group addresses marked with < are read by openHAB during startup. Future versions might support reading from one GA only. With *-control channels, the state is not owned by any device on the KNX bus, therefore no read requests will be sent by the binding, i.e. < signs will be ignored for them.

The element dpt is highly recommended and may change to a mandatory element in future versions. If omitted, the corresponding default value will be used (see the channel descriptions above).

# KNX Secure

NOTE: Support for KNX Secure is partly implemented for openHAB and should be considered as experimental.

# KNX IP Secure

KNX IP Secure protects the traffic between openHAB and your KNX installation. It requires a KNX Secure Router or a Secure IP Interface and a KNX installation with security features enabled in ETS tool.

For Secure routing mode, the so called backbone key needs to be configured in openHAB. It is created by the ETS tool and cannot be changed via the ETS user interface.

  • The backbone key can be extracted from Security report (ETS, Reports, Security, look for a 32-digit key) and specified in parameter routerBackboneKey.

For Secure tunneling with a Secure IP Interface (or a router in tunneling mode), more parameters are required. A unique device authentication key, and a specific tunnel identifier and password need to be available.

  • All information can be looked up in ETS and provided separately: tunnelDeviceAuthentication, tunnelUserPassword. tunnelUserId is a number which is not directly visible in ETS, but can be looked up in keyring export or deduced (typically 2 for the first tunnel of a device, 3 for the second one, ...). tunnelUserPasswort is set in ETS in the properties of the tunnel (below the IP interface you will see the different tunnels listed) denoted as "Password". tunnelDeviceAuthentication is set in the properties of the IP interface itself, check for a tab "IP" and a description "Authentication Code".

# KNX Data Secure

KNX Data Secure protects the content of messages on the KNX bus. In a KNX installation, both classic and secure group addresses can coexist. Data Secure does not necessarily require a KNX Secure Router or a Secure IP Interface, but a KNX installation with newer KNX devices which support Data Secure and with security features enabled in ETS tool.

NOTE: openHAB currently ignores messages with secure group addresses.

# Examples

The following two templates are sufficient for almost all purposes. Only add parameters to the Bridge and Thing configuration if you know exactly what functionality it is needed for.

# Type ROUTER mode configuration Template

knx.things:

Bridge knx:ip:bridge [
    type="ROUTER",
    autoReconnectPeriod=60 //optional, do not set <30 sec.
] {
    Thing device knx_device "knx_device_name" @ "knx_device_group" [
        //readInterval=3600 //optional, only used if reading values are present
    ] {
        //Items configurations
    }
}

# Type TUNNEL mode configuration Template

knx.things:

Bridge knx:ip:bridge [
    type="TUNNEL",
    ipAddress="192.168.0.111",
    autoReconnectPeriod=60 //optional, do not set <30 sec.
] {
    Thing device knx_device "knx_device_name" @ "knx_device_group" [
        //readInterval=3600 //optional, only used if reading values are present
    ] {
        //Items configurations
    }
}

# Full Example

//TUNNEL
Bridge knx:ip:bridge [
    type="TUNNEL",
    ipAddress="192.168.0.10",
    portNumber=3671,
    localIp="192.168.0.11",
    readingPause=50,
    responseTimeout=10,
    readRetriesLimit=3,
    autoReconnectPeriod=60,
    localSourceAddr="0.0.0"
] {
    Thing device generic [
        address="1.2.3",
        fetch=true,
        pingInterval=300,
        readInterval=3600
    ] {
        Type switch        : demoSwitch        "Light"       [ ga="3/0/4+<3/0/5" ]
        Type color         : demoColorLight    "Color"       [ hsb="6/0/10+<6/0/11", switch="6/0/12+<6/0/13", position="6/0/14+<6/0/15", increaseDecrease="6/0/16+<6/0/17" ]
        Type rollershutter : demoRollershutter "Shade"       [ upDown="4/3/50+4/3/51", stopMove="4/3/52+4/3/53", position="4/3/54+<4/3/55" ]
        Type contact       : demoContact       "Door"        [ ga="1.019:<5/1/2" ]
        Type number        : demoTemperature   "Temperature" [ ga="9.001:<5/0/0" ]
        Type dimmer        : demoDimmer        "Dimmer"      [ switch="5/0/0", position="5/0/2+<5/0/3", increaseDecrease="5/0/4" ]
        Type string        : demoString        "Message"     [ ga="5/3/1" ]
        Type datetime      : demoDatetime      "Alarm"       [ ga="5/5/42" ]
    }
}

//ROUTER
Bridge knx:ip:bridge [
    type="ROUTER",
    ipAddress="224.0.23.12",
    portNumber=3671,
    localIp="192.168.0.11",
    readingPause=50,
    responseTimeout=10,
    readRetriesLimit=3,
    autoReconnectPeriod=60,
    localSourceAddr="0.0.0"
] {}

knx.items:

Switch              demoSwitch         "Light [%s]"               <light>          { channel="knx:device:bridge:generic:demoSwitch" }
Color               demoColorLight     "Color [%s]"               <light>          { channel="knx:device:bridge:generic:demoColorLight" }
Dimmer              demoDimmer         "Dimmer [%d %%]"           <light>          { channel="knx:device:bridge:generic:demoDimmer" }
Rollershutter       demoRollershutter  "Shade [%d %%]"            <rollershutter>  { channel="knx:device:bridge:generic:demoRollershutter" }
Contact             demoContact        "Front Door [%s]"          <frontdoor>      { channel="knx:device:bridge:generic:demoContact" }
Number:Temperature  demoTemperature    "Temperature [%.1f °C]"    <temperature>    { channel="knx:device:bridge:generic:demoTemperature" }
String              demoString         "Message of the day [%s]"                   { channel="knx:device:bridge:generic:demoString" }
DateTime            demoDatetime       "Alarm [%1$tH:%1$tM]"                       { channel="knx:device:bridge:generic:demoDatetime" }

knx.sitemap:

sitemap knx label="KNX Demo Sitemap" {
  Frame label="Demo Elements" {
    Switch      item=demoSwitch
    Slider      item=demoDimmer
    Colorpicker item=demoColorLight
    Default     item=demoRollershutter
    Text        item=demoContact
    Text        item=demoTemperature
    Text        item=demoString
    Text        item=demoDatetime
  }
}

# Control Example

control.things:

Bridge knx:serial:bridge [
    serialPort="/dev/ttyAMA0",
    readingPause=50,
    responseTimeout=10,
    readRetriesLimit=3,
    autoReconnectPeriod=60
] {
    Thing device generic {
        Type switch-control        : controlSwitch        "Control Switch"        [ ga="3/3/10+<3/3/11" ]   // '<'  signs are allowed but will be ignored for control Channels
        Type dimmer-control        : controlDimmer        "Control Dimmer"        [ switch="3/3/50+3/3/48", position="3/3/46", increaseDecrease="3/3/49", frequency=300 ]
        Type color                 : controlColorLight    "Color"                 [ hsb="6/0/10", switch="6/0/12", position="6/0/14", 
        Type rollershutter-control : controlRollershutter "Control Rollershutter" [ upDown="3/4/1+3/4/2", stopMove="3/4/3", position="3/4/4" ]
        Type number-control        : controlNumber        "Control Number"        [ ga="1/2/2" ]
        Type string-control        : controlString        "Control String"        [ ga="1/4/2" ]
        Type datetime-control      : controlDatetime      "Control Datetime"      [ ga="5/1/30" ]
    }
}

Bridge hue:bridge:bridge "Philips Hue Bridge" [
    ipAddress="...",
    userName="..."
] {
    Thing 0210 1 "Color Lamp" [ lightId="1" ]
}

knx.items:

Switch        demoSwitch         "Light [%s]"               <light>          { channel="hue:0210:bridge:1:color", channel="knx:device:bridge:generic:controlSwitch" }
Dimmer        demoDimmer         "Dimmer [%d %%]"           <light>          { channel="hue:0210:bridge:1:color", channel="knx:device:bridge:generic:controlDimmer" }

# Console Commands

The KNX binding provides additional functionality which can be triggered from the openHAB console. Type openhab:knx on the openHAB console for further information.

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