Weinzierl KNX 886 Specification sheet

Weinzierl Engineering GmbH
Achatz 3
DE-84508 Burgkirchen / Alz
GERMANY
Tel: [phone] / 91 636 –0
[e-mail]
www.weinzierl.de
© 2020 Weinzierl Engineering GmbH Page 1/49
KNX Modbus Gateway with 250 data points
KNX Modbus RTU Gateway 886
Operation and installation manual
(Art. # 5256)

© 2020 Weinzierl Engineering GmbH Page 2/49
Content
1Application .........................................................................................................................3
2Installation and connection...............................................................................................3
2.1 KNX programming mode......................................................................................................4
2.2 Manual operation and status display....................................................................................4
3Reset to factory default settings.......................................................................................5
4Wiring scheme ...................................................................................................................5
4.1 Pluggable screw terminals ...................................................................................................5
4.2 Pin assignment ....................................................................................................................6
5ETS database .....................................................................................................................7
5.1 Description...........................................................................................................................7
5.2 General settings...................................................................................................................8
5.3 Modbus settings...................................................................................................................9
5.4 Datapoints N –M...............................................................................................................12
5.5 Channel function “DPT 01 – binary –1 bit”.........................................................................16
5.6 Channel function “DPT 03 – dimming –4 bit”.....................................................................20
5.7 Channel function “DPT 05 – percent –1 byte”....................................................................24
5.8 Channel function “DPT 05 – configured –1 byte”...............................................................25
5.9 Channel function “DPT 05 – unsigned –1 byte” ................................................................. 32
5.10 Channel function “DPT 06 – signed –1 byte”.....................................................................33
5.11 Channel function “DPT 07 – configured –2 bytes” .............................................................34
5.12 Channel function “DPT 07 – unsigned –2 bytes” ...............................................................41
5.13 Channel function “DPT 08 – signed –2 bytes” ...................................................................42
5.14 Channel Function “DPT 09 – float –2 bytes”......................................................................43
5.15 Channel Function “DPT 14 – float –4 bytes”......................................................................44
5.16 General information............................................................................................................48

© 2020 Weinzierl Engineering GmbH Page 3/49
1 Application
The KNX Modbus RTU Gateway 886 is a compact gateway between KNX TP and Modbus RTU
with 250 free configurable channels.
The device enables an easy integration of Modbus devices that support the RTU protocol via RS-
485 and can act as Modbus master or slave. The device can be used as a master for up to 25
slave devices.
The assignment between KNX objects and Modbus registers can be configured via parameters in
the ETS. No additional software is required. The KNX Bus and Modbus have a galvanic isolation
from each other.
Two push buttons and three LEDs enable a local operation and a visualization of the device status.
2 Installation and connection
The KNX Modbus RTU Gateway 886 is designed for installation on a DIN rail (35 mm) with a width
of 1 unit (18 mm). An installation friendly design with pluggable screw terminals helps to reduce the
cost of commissioning. It features the following controls and displays:
❶KNX bus connector
❷Programming LED
❸Button for programming mode
❹LED KNX (multicolor)
❺LED Mode (multicolor)
❻LED RTU (multicolor)
❼Button KNX
❽Button RTU
❾Pluggable screw terminals
The device has galvanic isolation between Modbus and KNX. The Modbus side must be connected
with 12...24 V⎓. The unchoked output voltage from the KNX power supply must not be used for
this purpose.
If the bus voltage is missing, the device is without function.

© 2020 Weinzierl Engineering GmbH Page 4/49
2.1 KNX programming mode
The KNX programming mode is activated/deactivated either by pressing the flushed KNX
programming button ❸or by simultaneously pressing the buttons ❼and ❽. The operation of
the programming mode at the front can be activated/deactivated in the ETS® with Prog. mode on
device front.
When the programming mode is active, the programming LED ❷and the LED Mode ❺light up
red.
2.2 Manual operation and status display
The LED KNX ❹lights up or flashes when KNX bus voltage is present.
The LED Mode ❺lights up or flashes when KNX bus voltage is present.
The LED RTU ❻lights up or flashes when supply voltage is present.
The synchronization of the KNX objects is triggered by pressing the button KNX ❼for a long time.
This is indicated by the LED Mode ❺lighting up in orange.
Pressing the button RTU ❽for a long time triggers the synchronization of the Modbus registers.
This is indicated by the LED Mode ❺lighting up in orange.
The LED KNX ❹is used to indicate the status of KNX communication. It flashes when sending
and receiving telegrams.
The LED RTU ❻indicates the status of the Modbus communication. It flashes when sending and
receiving telegrams.
Summary of the states of the LED Mode ❺:
LED Status
Meaning
LED lights green
The unit operates in normal operating mode.
LED lights red
The programming mode is active.
LED lights orange
The programming mode is not active.
Synchronization is active.
LED flashes red
The programming mode is not active.
Synchronization is not active.
The device is not loaded correctly, e.g. after aborting a download.
LED flashes green
The device is currently loaded by the ETS.

© 2020 Weinzierl Engineering GmbH Page 5/49
3 Reset to factory default settings
It is possible to reset the device to the factory default settings:
▪Disconnect the KNX Bus connector ❶from the device.
▪Press the KNX programming button ❸and keep it pressed down.
▪Reconnect the KNX Bus connector ❶to the device.
▪Keep the KNX programming button ❸pressed for at least another 6 seconds.
▪A short flashing of all LEDs (❷❹❺❻) visualizes the successful reset of the device to
factory default settings.
In the factory default settings, the device has the physical address 15.15.255 and no group
addresses are connected.
4 Wiring scheme
4.1 Pluggable screw terminals
The upper terminal is used to connect the supply voltage 12 ... 24 V⎓, the lower terminal to
connect the Modbus:

© 2020 Weinzierl Engineering GmbH Page 6/49
4.2 Pin assignment
The transmission line must be terminated at the last receiver of the Modbus transmission line with
a 120 Ohm / 0.25 W resistor. This resistor must be inserted directly between the two signal lines
before the input of the last device.
Only shielded and twisted cables should be used for Modbus.
Connection
Icon
Description
1
-
Ground connection for supply voltage
2
-
Ground connection for supply voltage
3
+
Positive connection for supply voltage 12 ... 24 V⎓
4
-
Ground connection for Modbus (connected to connection 1 and connection 2)
5
A
Data line A (+) for Modbus
6
B
Data line B (-) for Modbus
KNX
+
Positive connection for KNX bus
KNX
-
Ground connection for KNX bus

© 2020 Weinzierl Engineering GmbH Page 7/49
5 ETS database
The ETS5 database (for ETS 5.7 or newer) can be downloaded from the product website of the
KNX Modbus RTU Gateway 886 (www.weinzierl.de) or from the ETS online catalogue.
5.1 Description
The first page shows general information about the device.

© 2020 Weinzierl Engineering GmbH Page 8/49
5.2 General settings
Device name (30 characters)
Any arbitrary name can be assigned to the KNX Modbus RTU Gateway 886. The device name
should be meaningful, e.g. “Living room ground floor”. This helps the clarity of the ETS project.
Send delay after bus power return
The send delay of telegrams after the return of the bus voltage can be set via this parameter. In
this case, telegrams from the device are sent to the KNX bus in a delayed manner by the set time.
This reduces the bus load when the bus voltage returns. Other functions such as receiving
telegrams are not affected by this parameter.
Prog. mode on device front
In addition to the normal programming button ❸the device allows activating the programming
mode on the device front without opening the switchboard cover. The programming mode can be
activated and deactivated via pressing simultaneously both buttons ❼and ❽.
This feature can be enabled and disabled via the parameter Prog. mode on device front. The
recessed programming button ❸(next to the programming LED ❷) is always enabled and is not
affected by this parameter.
Manual operation (sync) on device
This parameter is used to configure manual operation on the device. The manual operation can be
activated or deactivated.
Manual operation enables synchronization of all channels in the direction to KNX (button KNX ❼)
and in the direction to Modbus (button RTU ❽).
Direction KNX:
All datapoints of the channels configured as “Modbus to KNX”send their current value on the KNX
bus.
Direction Modbus:
If the gateway is operating as Modbus master, all registers of the channels configured “KNX to
Modbus”are written to Modbus again.
Synchronization can be cancelled by pressing the buttons ❼and ❽simultaneously.

© 2020 Weinzierl Engineering GmbH Page 9/49
Heartbeat
Cyclic sending of values to the KNX bus, to indicate that the device is operational. For the Cycle
time values between 1 min and 24 h are selectable.
Group object
Type KNX
Size
Direction
GO 277 Heartbeat –Trigger
1.001
1 bit
To KNX
Telegram rate limitation
With this parameter the telegram rate limitation can be activated or deactivated.
Time telegram rate
If telegram rate limitation is activated, the time between the telegrams can be configured here.
Times between 0.1 sec. and 1.0 sec. can be selected.
The telegram rate limitation only occurs when the bus load is increased.
5.3 Modbus settings
KNX Gateway
This parameter defines the role of the KNX gateway within the client/server architecture of the
Modbus environment. Available are:
▪Modbus master
▪Modbus slave

© 2020 Weinzierl Engineering GmbH Page 10/49
Slave address (common)
Here the general slave address (0 ... 247) is set and used according to KNX Gateway
configuration.
Modbus master:
The slave address of the Modbus communication partner is entered here. If several Slave devices
are to be addressed, a specific slave address can be assigned per parameter page (e.g.
datapoints 1-10).
Modbus slave:
The slave address of the KNX gateway is entered here.
Baudrate
Configures the baudrate of the Modbus communication. The following are available:
▪1200 bits/s
▪2400 bits/s
▪4800 bits/s
▪9600 bits/s
▪19200 bits/s
▪38400 bits/s
▪56000 bits/s
▪115200 bits/s
Parity
Here the Modbus frame is parameterized with regard to parity and stop bit. The following options
are available:
▪Even (1 stop bit)
▪Odd (1 stop bit)
▪None (2 stop bits)
▪None (1 stop bit)
Byte order
Defines the order for the transmission of 2 byte values:
▪MSB first (high byte is sent first)
▪LSB first (low byte is sent first)
Register address
Here it is set on which address basis the register address is defined:
▪0 based
▪1 based
Time till next request (only in Master mode)
This parameter defines the minimum time for the next request. Used to slow down the master.

© 2020 Weinzierl Engineering GmbH Page 11/49
Time till next cycle (only in Master Mode)
This parameter defines the time after which a new request cycle has to begin. If the time is too
short, the cycle will not be completed. This is indicated by the red flashing of the RTU LED ❻.
Multi read requests (only in Master Mode)
When this parameter is activated, Modbus registers which lie one after the other in the channels
are combined in a multi-read request.
The slave address and the function code must be identical. The register address must
be continuous, but repetitions may occur. A maximum of 16 channels can be combined.
Example:
Type Slave address: Common
Channel 1 –MB to KNX –Read holding register –Address 0
Channel 2 –MB to KNX –Read holding register –Address 1
Channel 3 –MB to KNX –Read holding register –Address 2
Channel 4 –MB to KNX –Read holding register –Address 2
Channel 5 –MB to KNX –Read holding register –Address 3
Channel 6 –MB to KNX –Read holding register –Address 4
Channel 7 –MB to KNX –Read holding register –Address 4
The result is a read-multi-holding-register request for addresses 0 –4.
Diagnostic objects
Activated, objects for diagnostic are displayed and provide information about the communication
with the respective slave device.
Modbus master:
If no response is received from the slave device, “No communication –On”is sent to the KNX bus
via the diagnostic object.
Modbus slave:
If no request is received from the master within the time interval, “No communication –On”is sent
to the KNX bus via the diagnostic object.
Group object
Type KNX
Size
Direction
GO 276 Diagnostic: Slave (common) –No communication
1.001
1 bit
To KNX

© 2020 Weinzierl Engineering GmbH Page 12/49
5.4 Datapoints N –M
10 channels are combined per page.
Slave address type (only in master mode)
This parameter determines whether the general address or another slave address is to be used for
the configured channels on this page.
Slave address (only in master mode)
Here the slave address (0 ... 247) of the channels of this page is set.
Slave description (only in master mode)
If the diagnostic is activated, the diagnostic object of this page can be named here.
Group object
Type KNX
Size
Direction
GO 251 Diagnostic: Slave (page 1) –No communication
1.001
1 bit
To KNX

© 2020 Weinzierl Engineering GmbH Page 13/49
Datapoint type
This parameter activates and defines the KNX interface and the function of this channel. The
following options are available:
▪Disabled
▪DPT 01 –binary –1 bit
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Switch –1 bit
1.001
1 bit
…
▪DPT 03 –dimming –4 bits
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Dimming –4 bits
3.007
4 bits
…
▪DPT 05 –percent –1 byte
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Percent –1 byte
5.001
1 byte
…
▪DPT 05 –configured –1 byte
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Configured –1 byte
5.010
1 byte
…
▪DPT 05 –unsigned –1 byte
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Unsigned –1 byte
5.010
1 byte
…
▪DPT 06 –signed –1 byte
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Signed –1 byte
6.010
1 byte
…
▪DPT 07 –configured –2 bytes
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Configured –2 bytes
7.001
2 bytes
…
▪DPT 07 –unsigned –2 bytes
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Unsigned –2 bytes
7.001
2 bytes
…
▪DPT 08 –signed –2 bytes
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Signed –2 bytes
8.001
2 bytes
…

© 2020 Weinzierl Engineering GmbH Page 14/49
▪DPT 09 –float –2 bytes
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Float –2 bytes
9.001
2 bytes
…
▪DPT 14 –float –4 bytes
Group object
Type KNX
Size
Direction
GO 1 Channel 1: … – Float –4 bytes
14.000
4 bytes
…
Description (30 characters)
Any name can be assigned to the channel. However, this should be unique and meaningful, which
makes it easier to work with the associated group objects later, since the name assigned is
displayed there as a description. If no name is assigned, the group objects are designated as
“Channel N: ...”.
Direction
The KNX specific communication direction is set here:
▪KNX to Modbus (group object is input)
Group object
Type KNX
Size
Direction
GO 1 Channel 1: Input –…
Depending on DPT
From KNX
▪Modbus to KNX (group object is output)
Group object
Type KNX
Size
Direction
GO 1 Channel 1: Output –…
Depending on DPT
To KNX
Send condition
If the group object is defined as an output, the time at which the object sends the value to the KNX
bus is configured here. The following options are available:
▪Read only
Object sends only on read requests
▪On change
Object sends on value change
▪Cyclic
Object sends after cycle time
▪Cyclic and on change
Object transmits after cycle time and on value change
Cycle time
The time for send condition cyclic.
Type
This parameter defines the function of the channel as well as the size of the Modbus register used.

© 2020 Weinzierl Engineering GmbH Page 15/49
Depending on the parameter Datapoint type N various channel functions are possible, which will
be discussed in more detail in the following chapters.
For “Value in word register”it should be noted that the channel does not work in case of incorrect
configuration.
The Bit count and Offset together must not be greater than 16.
The value must fit into Bit count, for example Bit count = 1 →“Value” = 0 or 1.
Function
The Modbus function code for this channel is configured here.
Different function codes can be configured depending on KNX gateway (Modbus master/slave),
Direction and Type.
Word register:
Modbus Master | KNX to Modbus
▪Write single holding register –06
▪Write multi holding registers –16
(for “DPT 14” and “Double word register”)
Modbus Master | Modbus to KNX
▪Read holding registers –03
▪Read input registers –04
Modbus Slave | KNX to Modbus
▪Read holding registers –03
▪Read input registers –04
Modbus Slave | Modbus to KNX
▪Write single/multi holding registers –06, 16
Bit Register:
Modbus Master | KNX to Modbus
▪Write single coil –05
Modbus Master | Modbus to KNX
▪Read coils –01
▪Read discrete inputs –02
Modbus Slave | KNX to Modbus
▪Read coils –01
▪Read discrete inputs –02
Modbus Slave | Modbus to KNX
▪Write single/multi coils –05, 15

© 2020 Weinzierl Engineering GmbH Page 16/49
Address
Here the address of the Modbus register is configured. An address range from 0 ... 65535 is
available.
If address 0 is configured with “1 based”, this is a static error which deactivates the
channel function and is indicated by LED RTU ❻lighting up in red.
Polling interval (only in Master mode and for Modbus to KNX)
This defines the cyclic intervals of read requests for the respective register. The following options
are available:
▪Every cycle
▪Every second cycle
▪Every fourth cycle
▪Every sixth cycle
▪Every eighth cycle
5.5 Channel function “DPT 01 – binary –1 bit”
Type
The following types are configurable:
▪Bit register
1 bit (KNX) sets bit register (Modbus)
▪Bit in word register
1 bit (KNX) sets 1 bit in word register (Modbus)
▪Value in word register
1 bit (KNX) is mapped to value in word register (Modbus)
5.5.1 Type –Bit register
Value inverted
If yes, the inverted value of the group object corresponds to the value of the bit register.

© 2020 Weinzierl Engineering GmbH Page 17/49
5.5.2 Type –Bit in word register
Position (register)
Defines the bit in the word register.
Value inverted
If yes, the inverted value of the group object corresponds to the value of the bit in the word register.
5.5.3 Type –Value in word register
Bit count
This parameter defines the size of the value in the word register (in bits).
Offset
This parameter defines the position of the value in the word register (offset from the right in bits).

© 2020 Weinzierl Engineering GmbH Page 18/49
5.5.3.1 Direction –KNX to Modbus
Behaviour on receiving data ‘ON’
Here it can be configured whether a value is to be set in the register when an ‘ON’telegram is
received.
Value
The value that is set in the register when an ‘ON’telegram is received.
Behaviour on receiving data ‘OFF’
Here it can be configured whether a value is to be set in the register when an ‘OFF’telegram is
received.
Value
The value that is set in the register when an ‘OFF’telegram is received.

© 2020 Weinzierl Engineering GmbH Page 19/49
5.5.3.2 Direction –Modbus to KNX
Value
The value for which the register is checked. Depends on Bit count and Offset.
Behaviour on value higher
This parameter defines the behaviour of the group object if the register value is greater than the
parameterized value. The following options are available:
▪No reaction
▪Send ‘ON’
▪Send ‘OFF’
Behaviour on value match
This parameter defines the behaviour of the group object in case the register value corresponds to
the parameterized value. The following options are available:
▪No reaction
▪Send ‘ON’
▪Send ‘OFF’
Behaviour on value lower
This parameter defines the behaviour of the group object in case the register value is smaller than
the parameterized value. The following options are available:
▪No reaction
▪Send ‘ON’
▪Send ‘OFF’

© 2020 Weinzierl Engineering GmbH Page 20/49
5.6 Channel function “DPT 03 – dimming –4 bit”
Type
The following types are configurable:
▪Bit register
4 bit dimming command (KNX) sets bit register (Modbus)
▪Value in word register
4 bit dimming command (KNX) is mapped to value in word register (Modbus)
5.6.1 Type –Bit Register
5.6.1.1 Direction –KNX to Modbus
Behaviour on receiving data ‘DIM UP’
This parameter defines the behaviour of the bit register in case a ‘DIM UP’telegram has been
received at the group object. The following options are available:
▪No reaction
▪Register ‘1’
▪Register ‘0’
Behaviour on receiving data ‘DIM DOWN’
This parameter defines the behaviour of the bit register in case a ‘DIM DOWN’telegram was
received at the group object. The following options are available:
▪No reaction
▪Register ‘1’
▪Register ‘0’