LSI DNB105.2 User manual

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Environmental monitoring solutions
Ultrasonic anemometer
DNB105.2
User manual
Updated 04/05/2021

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Index
1 Description................................................................................................................................................. 4
1.1 Main features .................................................................................................................................... 4
1.2 Technical specifications..................................................................................................................... 4
2 Installation................................................................................................................................................. 5
2.2 Mechanical installation...................................................................................................................... 6
2.3 Electrical connections........................................................................................................................ 7
2.3.1 RS485 serial connection ............................................................................................................ 8
2.3.2 Analog Output connection ........................................................................................................ 8
2.3.3 Connection to LSI LASTEM data logger...................................................................................... 8
3 Configuration............................................................................................................................................. 9
4 Modbus-RTU............................................................................................................................................ 10
5 Maintenance............................................................................................................................................ 11
5.1 Testing ............................................................................................................................................. 11
5.2 Periodic maintenance...................................................................................................................... 12
6 Accessories / Spare parts......................................................................................................................... 13
7 Disposal.................................................................................................................................................... 13
8 How to contact LSI LASTEM..................................................................................................................... 13

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1Description
1.1 Main features
DNB105.2 is 2-axes ultrasonic anemometer for measuring wind speed and wind direction.
It is ideal for general meteorological applications requiring high wind speed range, no moving parts for low-
maintenance or measurements with fast response even in very low-range wind speed conditions.
Sensor is equipped with compass and the Tilt angles detection system (inclination), to determine the spatial
orientation of the anemometer at any time. This allows it to be installed even on mobile vehicles (boats,
mobile environmental monitoring vehicles, etc.)
It has two 4÷20 mA analog outputs, one for wind speed and one for wind direction, and one RS485 serial
output with Modbus-RTU protocol.
The anemometer can be connected to LSI LASTEM acquisition systems, or any other device using such kind
of input.
1.2 Technical specifications
DNB105.2
Wind speed
Principle
Ultrasounds
Measuring range
0÷85 m/s
Resolution
0.01 m/s
Accuracy
± 0.2 m/s or ± 2%, the greatest (0÷60 m/s), ± 3% (> 60 m/s)
Wind direction
Principle
Ultrasounds
Measuring range
0÷359.9°
Resolution
0.1°
Accuracy
± 2° RMSE (wind speed > 2 m/s)
Compass
And Tilt angle
Resolution
0.05°
Accuracy
± 1°
General features
Power supply
12÷30 Vdc
Power consumption
60 mA @ 24 Vdc
Serial outputs
Isolated RS485
Communication protocols
Modbus-RTU
Analog outputs
2 (wind speed and direction) x 4÷20 mA (max. load 500 Ω)
Electrical connection
19-pole M23 male connector
Operating temperature
-40÷70 °C (without ice)
Protection degree
IP 66
Weight
640 g approx.
Housing
ASA with aluminum and AISI 316 metal parts
Mounting
Mast ∅40 mm external and ∅36 mm internal
Data logger compatibility
M-Log (ELO008), R-Log (ELR515), E-Log, A-Log (with ALIEM)

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2Installation
For the installation choose a well-exposed spot for the anemometer. The WMO (World Meteorological Or-
ganization) suggests that the sensor should be assembled 10 m off the ground; in a place where the dis-
tance between the anemometer and surrounding obstacles which might disturb the measurements is at
least 10 times the height of those objects from the ground. As such a position is difficult to find, the WMO
suggests that the sensor should be assembled in a spot which is reasonably uninfluenced by local obstruc-
tions.
2.1 General safety rules
Please read the following general safety rules in order to avoid injuries to people and prevent damages to
the product or to possible other products connected with it. In order to avoid any damages, use this prod-
uct exclusively according to the instructions herein contained.
The installation and maintenance procedures must be carried-out only by authorized and skilled service
personnel.
Power the instrument in a suitable manner. Pay attention and observe the power supplies like indicated for
the model in your possession.
Carry-out all connections in a suitable manner. Pay strict attention to the connection diagrams supplied
with the instrument.
Do not use the product in case of suspected malfunctions. In case of suspected malfunction, do not power
the instrument and contact authorized technical support immediately.
Before you carry-out any operation on electrical connections, power supply system, sensors and communi-
cation apparatus:
•Disconnect the power supply.
•Discharge the accumulated electrostatic discharges touching an earthed conductor or apparatus.

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2.2 Mechanical installation
1. Pass the connection cable (DWA8xx.1) in-
side the support mast and connect the 19-
pole M23 female connector of the cable to
the 19-pole M23 male connector situated
at the bottom of the anemometer. Ensure
connection stability by tightening the con-
nector external nut.
2. Mount the anemometer
on the mast (∅40 mm
external and ∅36 mm in-
ternal). In case of mast ∅
50 mm external, the
DNB191 adapter should
be used.
3. The anemometer does not require
positioning as the orientation is de-
termined by the internal compass.
However, if the sensor was re-
quested with the compass disabled,
it must be positioned with the ar-
row towards the North and in-
stalled in a perfectly vertical posi-
tion.
4. Fix it on the sup-
port mast by
tightening the ca-
ble tie at the bot-
tom of the ane-
mometer.
Please note the following:
➢The anemometer measures the provenience of the wind.
➢The measure refers:
oto magnetic North if the compass is active (default condition)
oto geographical North (reference to the arrow) if the compass is disabled
➢Geographical North differs from magnetic North indicated by the compass; the difference, called
magnetic declination, depends on the area in which the sensor is installed; for example, in North
America it is about 15° while in Europe it is less than 3°.

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2.3 Electrical connections
All connections are performed through a 19-pole M23 male connector situated at the bottom of the ane-
mometer. The figure and the table below show numbers and function of the connector contacts:
Pin connector
Symbol
Description
1
Not used
2
Not used
3
RX +
Serial receive (input) positive
4
HEAT -
Optional Heater power supply negative
5
HEAT +
Optional Heater power supply positive (24 Vdc)
6
HEAT -
Optional Heater power supply negative
7
HEAT +
Optional Heater power supply positive (24 Vdc)
8
GND
Serial ground (isolated from V –)
9
TX -
Serial transmission (output) negative “DATA –” main RS485 output
10
AUX_B
“DATA +” auxiliary RS485 output (D+)
11
AUX_A
“DATA –” auxiliary RS485 output (D-)
12
V -
Anemometer power supply negative
13
RX -
Serial receive (input) negative
14
OUT 1
Analog output 1 positive
15
GND
Analog ground (isolated from V –)
16
OUT 2
Analog output 2 positive
17
TX +
Serial transmission (output) positive “DATA +” main RS485 output
18
Not used
19
V +
Anemometer power supply positive (12÷30 Vdc)
--
SHIELD
Cable shield

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2.3.1 RS485 serial connection
For more information regarding RS485, consult the EIA (Electronic Industries Association).
2.3.2 Analog Output connection
OUT 1 and OUT 2 are associated to wind speed and wind direction respectively.
2.3.3 Connection to LSI LASTEM data logger
For the wiring connection see the DISACC210021 supplied with the anemometer.

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3Configuration
The anemometer supplied from LSI LASTEM is ready for working with its data loggers. The table below
shows its configuration.
Section
Parameter
Value
General settings
Enabling magnetic compass
Enabled
Wind speed thresholds
0.2 (m/s)
Method for calculation of average of
wind speed
Vector averaging
Method for calculation of average of
wind direction
0÷359°
Time interval for the calculation of aver-
age
1 s
Measuring Units
Wind speed
m/s
Resolution (number of decimals)
Wind speed
2
Analog outputs
AN1
AN2
Wind speed
Wind direction (0-359°)
Offset and direction
4÷20 mA
Full scale of wind speed analog output
85 m/s
Operation mode
Mode
Modbus-RTU
Modbus-RTU
Address
1
Baud rate
19200
Interface
RS485
Parity and stop bits
8E1
Waiting time after transmission
Wait 3.5 characters
For changing some operating parameter, contact LSI LASTEM.

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4Modbus-RTU
The Modbus function code 04h (Read Input Registers) allows reading the values measured by the anemom-
eter. The following table lists the Input Registers available.
Register
number
Quantity
Format
1
Instantaneous wind speed (x100)
unsigned 16 bits
2
Instantaneous wind direction in degrees (x10)
unsigned 16 bits
3
Sonic temperature measured by the transducers pair of the X axis (x10)
16 bits
4
Sonic temperature measured by the transducers pair of the Y axis (x10)
16 bits
5
Average of the two sonic temperatures measured by the two transducers
pairs (x10)
16 bits
9
Compass angle in degrees (x10)
unsigned 16 bits
11
Average wind speed (x100)
unsigned 16 bits
12
Average wind direction in degrees (x10)
unsigned 16 bits
18
Status register
bit0=1 ⇒Speed measurement error
bit1=1 ⇒Not used
bit2=1 ⇒Not used
bit3=1 ⇒Not used
bit4=1 ⇒Pressure measurement error
bit5=1 ⇒Not used
unsigned 16 bits
19
Wind speed unit of measurement
bit0=1 ⇒m/s
bit1=1 ⇒cm/s
bit2=1 ⇒km/h
bit3=1 ⇒kn
bit4=1 ⇒mph
unsigned 16 bits
20
Temperature unit of measurement
0 ⇒°C
1 ⇒°F
unsigned 16 bits
25
Tilt_Y in degrees (x10)
16 bits
26
Tilt_X in degrees (x10)
16 bits
Note: for quantities with configurable measurement unit, the measurement value is expressed in the unit
set in the anemometer.
For additional information regarding the protocol, visit the website www.modbus.org.