GHM Delta OHM HD53LS.A User manual

Operating manual
Ultrasonic anemometers
HD53LS.A / HD53LS.S
www.deltaohm.com
English
Keep for future reference.

HD53LS - 2 - V1.3
TABLE OF CONTENTS
1 INTRODUCTION .................................................................................................... 3
2 TECHNICAL SPECIFICATIONS ...............................................................................
3 MEASURING PRINCIPLE OF WIND SPEED AND DIRECTION .................................. 5
INSTALLATION ..................................................................................................... 6
4.1 ALIGNMENT OF THE INSTRUMENT .............................................................................. 7
4.2 ELECTRICAL CONNECTIONS ..................................................................................... 8
4.2.1 RS232 SERIAL CONNECTION ...................................................................... 9
4.2.2 RS485 SERIAL CONNECTION (ONLY HD53LS.S) ............................................... 9
4.2.3 ANALOG OUT UTS CONNECTION (ONLY HD53LS.A) ......................................... 10
4.2.4 CONNECTION OF RS52 CABLE.................................................................... 11
5 CONFIGURATION ................................................................................................ 12
5.1 SERIAL COMMANDS ............................................................................................ 12
6 MODBUS-RTU MODE (ONLY HD53LS.S) ............................................................... 18
7 INSTRUMENT STORAGE ...................................................................................... 19
8 SAFETY INSTRUCTIONS ...................................................................................... 19
9 ACCESSORIES ORDERING CODES ....................................................................... 20

HD53LS - 3 - V1.3
1INTRODUCTION
HD53LS.A and HD53LS.S are 2-axis ultrasonic static anemometers for the measurement of:
•Wind speed and direction
•U-V Cartesian components of wind speed
•Wind Gust (only HD53LS.S)
The average of wind speed and direction over a period configurable up to 10 minutes is calcu-
lated.
Wind speed and direction are determined by measuring the transit time of ultrasonic pulses
between two pairs of ultrasonic transducers.
HD53LS.A has two analog outputs, for wind speed and direction, which are factory-configurable
within 4÷20 mA (standard), 0÷1 V, 0÷5 V or 0÷10 V (to be specified when ordering).
HD53LS.S has RS485 MODBUS-RTU output.
All models are equipped with a magnetic compass.
Mounting on ∅ 40 mm mast. The electric connection is performed through a M23 19-pole con-
nector situated on the bottom of the instrument.
The low power consumption of the instrument allows installation in remote sites, with power
supplied by photovoltaic panel and backup battery.
The absence of moving parts minimizes the instrument maintenance.

HD53LS - 4 - V1.3
2TECHNICAL SPECIFICATIONS
Wind speed
Used sensor Ultrasounds
Measuring range 0…50 m/s
Resolution 0.01 m/s
Accuracy ± 0.2 m/s or ± 2%, the greatest (0…35 m/s), ± 3% (> 35 m/s)
Wind direction
Used sensor Ultrasounds
Measuring range 0…359.9°
Resolution 0,1°
Accuracy ± 2° RMSE from 1.0 m/s
Compass
Sensor Magnetic
Measuring range 0…360°
Resolution 0.1°
Accuracy ± 1°
General features
ower Supply 10…30 Vdc (15…30 Vdc for version with 0÷10 V analog out-
put)
ower consumption 26 mA @ 12 Vdc
Analog output 2 analog outputs: one for wind speed and one for wind di-
rection (only in HD53LS.A).
Analog output type is 4…20 mA as standard; 0…1 V, 0…5 V
or 0…10 V available on request.
Analog output refresh rate 1 Hz.
Digital output RS485 MODBUS-RTU (only in HD53LS.S)
Averaging interval Configurable from 1 s to 10 min
Electrical connection M23 connector
Operating temperature -20…+55 °C
Survival speed 90 m/s
rotection degree I 66
Dimensions H=179mm, ∅=150mm
Weight 640 g approx.
Case ASA. Metal parts: AISI 316

HD53LS - 5 - V1.3
3MEASURING PRINCIPLE OF WIND SPEED AND DIRECTION
Wind speed and direction are determined by measuring the time taken by ultrasonic pulses to
cover the distance from the transducer that generates the pulse to the receiving transducer.
The instrument uses 2 pairs of transducers oriented along two orthogonal axes. Detecting the
wind speed along two axes allows determining not only the intensity but also the wind direc-
tion.
The instrument measures the travel time of the ultrasonic pulse between the two transducers
of the same pair in both directions. The travel times in the two opposed directions are defined
as tA (forward direction time) and tR (reverse direction time).
If wind speed is zero, tA and tR values are the same. In the presence of wind, one of the two
time values is greater than the other and the comparison between the two time values allows
to determine the direction and the intensity of the wind.
Measuring the travel time in both directions allows to cancel the dependence of the transmis-
sion speed of ultrasounds in the air from the environmental conditions of temperature, humidi-
ty and barometric pressure.
Measurement along first axis Measurement along second axis
The travel times of the ultrasonic pulses are given by:
W
A
V
C
D
t
+
=
W
R
V
C
D
t
−
=
Where:
D = Distance between the two transducers of the same pair
C = Sound speed
VW = Component of wind speed along the measurement axis
Measuring the two travel times allows determining the wind speed component:





−⋅=
RA
Wtt
D
V11
2
Axis U
Transducer Transducer
Transducer Transducer
Axis V

HD53LS - 6 - V1.3
INSTALLATION
To install the instrument, pass the connection cable inside 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 instrument. Ensure connection stability by tightening the connector external nut.
Align the arrow on the housing of the instrument to the North (see par. 4.1 “Alignment”), then
fix it on the support mast by tightening the cable tie at the bottom of the instrument.
The support mast, having 40 mm maximum outer diameter and 36 mm minimum inner diame-
ter, should be positioned on a stable surface.
The instrument should be installed vertically and in an open area, far from obstructions located
in the vicinity that might alter the natural air flow. Any close objects (such as buildings, trees,
pylons, etc.) should be at a distance equal to at least ten times their height.
In the presence of close objects, it is advisable to place the instrument at a height of 10 m.
For open-space installations, the instrument can be installed using the tripod HD2005.20
(2 m) or HD2005.20.1 (3 m).
If the instrument is installed on a building, the height of the instrument should be at least 1.5
times the minimum value between the height of the building and the roof longest diagonal.

HD53LS - 7 - V1.3
Mount the instrument far from magnetic materials and devices that generate magnetic fields
(electric motors, electric power cables, electric transformers, radars, radio transmitters etc.) in
order to prevent faulty indications from the magnetic compass.
In case of mobile installations (for example on a boat), take into account that the instrument
measures the relative (apparent) wind speed with respect to the instrument. To determine the
absolute (real) wind speed one should consider the movement velocity of the instrument.
The instrument is factory-calibrated and does not require additional interventions of the user.
For the available configuration parameters, the related factory settings and the commands to
modify the parameters, see Chapter 6 “CONFIGURATION”.
In the model HD53LS.S, the RS485 MODBUS-RTU mode will be active 10 seconds after power
up.
.1 ALIGNMENT OF THE INSTRUMENT
The instrument is equipped with a magnetic compass, and wind speed and direction measure-
ments are automatically compensated and referred to magnetic North, even if alignment to
North is not performed. This allows obtaining accurate measurements even in case of mobile
installations.
It is possible to disable the compass compensation of the wind speed and direction measure-
ments. In this case it is necessary to align the instrument during installation. The arrows on
the case will facilitate the alignment.
For an accurate alignment, connect the instrument to a C (see following chapters for commu-
nication protocols), then rotate the instrument on its vertical axis until the compass measures
0.0° ± 0.1°.
When evaluating the wind direction, one should take into account that the geographic North
differs from the magnetic North indicated by a magnetic compass. The difference, named
magnetic declination, depends on the area where the instrument was installed (for example,
about 15° in North-America and less than 3° in Europe).
If wind speed and direction values are given in polar coordinates, 0° angle corresponds to a
wind coming from North.
Arrow for
alignement
to North
Supporting plate
of ultrasonic sensors

HD53LS - 8 - V1.3
.2 ELECTRICAL CONNECTIONS
All connections are performed through a 19-pole M23 male connector situated at the bottom of
the instrument. The figure and the table below show numbers and function of the connector
contacts and the corresponding wires of the optional CP52.x cable:
Connector
pin No
CP52.x cable
wire No/color Symbol Description
1 Not connected
2 2 / Blue Not connected
3 3 / Yellow RX + RX for RS232 connection
4 Not connected
5 Not connected
6 6 / ink Not connected
7 7 / Violet Not connected
8 8 / Grey GND Serial ground
9 9 / White TX - DATA - for RS485 connection (only HD53LS.S)
TX for RS232 connection
10 Not connected
11 Not connected
12 12 / Black GND Instrument power supply negative
13 4 / Grey- ink Not connected
14 10 / Brown OUT 1 Analog output 1 positive (only HD53LS.A)
15 GND Analog ground (only HD53LS.A)
16 11 / Green OUT 2 Analog output 2 positive (only HD53LS.A)
17 5 / Red-Blue TX + DATA + for RS485 connection (only HD53LS.S)
18 V + Instrument power supply positive (10…30 Vdc)
19 1 / Red V + Instrument power supply positive (10…30 Vdc)
-- Black (thick wire) SHIELD Cable shield
Connector
Reference
Visible side
male
connector

HD53LS - 9 - V1.3
.2.1 RS232 SERIAL CONNECTION
For RS232 connection, TX-, RX+ and serial GND signals (pin 9, 3 and 8 of M23 connector) are
used, to be connected respectively to RX, TX and GND signals of RS232 port on C (pin 2, 3
and 5 of 9-pole SubD connector). The length of RS232 cables should not exceed 15 m.
The RS232 serial connection is used for the instrument configuration (via serial commands or
HD52.3D-S software) and for displaying the measurements in real time (via HD52.3D-S soft-
ware).
If the C is not equipped with RS232 serial ports, the RS52 adapting cable (with built-in
USB/RS232 converter) can be inserted between the C and the instrument (see paragraph 4.2.4).
.2.2 RS 85 SERIAL CONNECTION (ONLY HD53LS.S)
Thanks to RS485 connection, multiple instruments can be connected to a multi-point network.
Instruments are connected in sequence through a twisted-pair shielded cable for signals and a
third wire for ground.
Line terminations should be placed at the two ends of the network. The cable shield should be
connected to both ends of the line.
The maximum number of devices that can be connected to the RS485 line (Bus) depends on the
load characteristics of the devices to be connected. The RS485 standard requires that the total
Reference of female
connector solder side
ower supply
ower su
p
ply
RS232
ort
RS485/USB or RS485/RS232
converter or data logger
with RS485 port
Other sensors with
RS485 output
Termination Termination
Reference of female
connector solder side

HD53LS - 10 - V1.3
load does not exceed 32 unit loads. The load of an HD52.3D… anemometer is equal to ¼ of unit
load. If the total load is greater than 32 unit loads, divide the network into segments and add a
signal repeater between a segment and the successive one. Line termination should be applied
at both ends of each segment.
The maximum length of the cable depends on the transmission speed and the cable character-
istics. Typically, the maximum length is 1200 m. The data line should be kept separated from
any power lines in order to prevent interference with the transmitted signal.
Each instrument on the network is univocally identified by an address. Multiple transmitters
with the same address should not be placed on the network.
If the instrument is connected to a data logger, the possibility to connect multiple sensors to
the network depends on the data logger capacity to manage multiple sensors.
MODBUS-RTU protocol is used with RS485 connection.
Before connecting the instrument to the network, configure address and Baud Rate (see chap-
ter 6 “CONFIGURATION”).
.2.3 ANALOG OUTPUTS CONNECTION (ONLY HD53LS.A)
Connect the outputs according to one of the two schemes below, depending on the output
type, current (standard) or voltage (on request), available in the instrument. OUT 1 and
OUT 2 are associated to wind speed and direction respectively. To change the type of speed
and direction measurements associated to the outputs, see chapter 6 “CONFIGURATION”.
Current outputs are active. Load resistance: RL < 300 Ω.
Load resistance: RL > 10 kΩ.
ower supply
ower supply
Reference of female
connector solder side
Reference of female
connector solder side
Current
outputs
4…20mA
Voltage outputs