deltaohm HD52 Ultrasonic anemometers Instruction Manual

deltaohm HD52 Ultrasonic anemometers

INTRODUCTION

The instruments of the series HD52.3D… are 2-axis ultrasonic static anemometers. The available measurement options combine in a single instrument the main quantities of meteorological interest, making the instrument like a compact and light meteorological station.
Measured quantities:

• Wind speed and direction, U-V Cartesian components of wind speed
• Wind Gust
• Relative Humidity and temperature (optional)
• Global solar radiation (optional)
• Barometric pressure (optional)
• Rainfall (optional)

The “Rainfall” and “Global solar radiation” options are alternatives (they cannot be both pre-sent in the same instrument).
The average of wind speed and direction over a period configurable up to 10 minutes is calcu-lated.
All models are equipped with a magnetic compass.
Wind speed and direction are determined by measuring the transit time of ultrasonic pulses between two pairs of ultrasonic transducers.
RS232, RS485, RS422 and SDI-12 serial interfaces are available with NMEA, MODBUS-RTU and SDI-12 communication protocols.
All versions have 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 or-dering).
The heater option prevents the accumulation of snow and ice formation, allowing precise measurements in all environmental conditions.
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 instrument maintenance.

MODELS

The table below shows the optional features included in the various models of the series.

| OPTIONS INCLUDED
---|---

Model

|

Atmospheric pressure

| Relative humidity

+

Temperature

|

Global solar radiation

|

Rainfall

|

Heating

HD52.3D [R]| | | | |

With option R

in the code

HD52.3D4 [R]| | | |
HD52.3DP [R]| | | |
HD52.3DP4 [R]| | | |
HD52.3D17 [R]| | | |
HD52.3D147 [R]| | | |
HD52.3DP17 [R]| | | |
HD52.3DP147 [R]| | | |
HD52.3DT147| | | | | Not available

TECHNICAL SPECIFICATIONS

Wind speed

• Sensor;Ultrasounds
• Measuring range;0…60 m/s (0…50 m/s with rain gauge option)
• Resolution ; 0.01 m/s
• Accuracy;± 0.2 m/s or ± 2%, the greatest (0…35 m/s), ± 3% (> 35 m/s)

Wind direction

• 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°

Air temperature ( needs option 17 )

• Sensor; Pt100
• Measuring range;-40…+70 °C
• Resolution;0.1 °C
• Accuracy;± 0.15 °C ± 0.1% of measurement

Relative humidity ( needs option 17 )

• Sensor; Capacitive
• Measuring range;0…100%RH
• Resolution;0.1%
• Accuracy (@ T = 15…35 °C);± 1.5%RH (0…90%RH), ± 2%RH (remaining range)
• Accuracy (@ T = -40…+70 °C) ;± (1.5 + 1.5% of measurement )%RH

Barometric Pressure ( needs option 4 )

• Sensor ;Piezoresistive
• Measuring range;300…1100 hPa
• Resolution;0.1 hPa
• Accuracy;± 0.5 hPa @ 20 °C

Solar radiation ( needs option P )

• Sensor ; Thermopile
• Measuring range;0…2000 W/m2
• Resolution;1 W/m2
• Accuracy;2nd Class Pyranometer

Rainfall ( needs option T )

• Sensor; Tipping bucket
• Resolution;0.2 mm
• Accuracy;99% up to 120 mm/h
• Maximum rainfall rate;2000 mm/h
• Collector area;127 cm2

General features

• Power Supply;10…30 Vdc
• Power consumption;26 mA @ 24 Vdc without heater 8 W @ 24 Vdc with heater
• Serial outputs; RS232, RS485 (¼ Unit Load), RS422 and SDI-12
• Communication protocol; NMEA, MODBUS-RTU, SDI-12, proprietary RS232, and RS485
• Analog outputs;2 analog outputs, for wind speed and direction.
• Output at choice among 4…20 mA (standard), 0…1 V, 0…5 V, and 0…10 V (option 0…10 V needs 15…30 Vdc power supply)
• Wind speed averaging interval; Configurable from 1 s to 10 min
• Electrical connection;19-pole M23 male connector
• Operating temperature; -40…+70 °C

Minimum temperature for the rainfall sensor 1 °C

• Protection degree; IP 66
• Survival speed;90 m/s (60 m/s with rain gauge option)
• Weight ;About 1 kg (version HD52.3DP147) About 1.5 kg (version HD52.3DT147)
• Case; Plastic material. Metal parts: AISI 316

Dimensions (mm)

DESCRIPTION

1. Pyranometer
2. Ultrasonic sensors for the measurement of wind speed and direction
3. Protective shield from solar radiation for relative humidity and temperature sensors
4. Fixing clamp to Ø 40 mm mast

Note: in the models measuring barometric pressure, the pressure sensor is inside the instrument.

1. Rain gauge
2. Ultrasonic sensors for the measurement of wind speed and direction
3. Protective shield from solar radiation for relative humidity and temperature sensors
4. Fixing clamp to Ø 40 mm mast

MEASURING THE 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 transmission speed of ultrasounds in the air from the environmental conditions of temperature, humidity and barometric pressure. 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

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 instrument to the desired direction (see par. 5.1 “Alignment”), then fix it on the sup-port 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 (except version with rain gauge option). For version with rain gauge option it is recommended to place the instrument at a height not exceeding 3 m (the precipitation measurement is standardized at ground level, as it is very af-fected by the presence of wind). It is very important to place the instrument on a rigid mast, as the oscillation of the mast could cause false detections of the tipping bucket of the rain gauge.
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.
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.
All instrument sensors are factory-calibrated and do not require additional interventions of the user.
Unless otherwise requested, with factory settings the instrument starts in configuration mode at power up and stands in waiting to receive the commands for the setting of the operating pa-rameters through a RS232 serial connection. To know the available configuration parameters, the related factory settings, the commands to modify the parameters and to select the operat-ing mode, see Chapter 6 “CONFIGURATION”. If, however, the instrument is already set to op-erate in one of the available operating modes (SDI-12, NMEA, MODBUS-RTU, proprietary RS232, proprietary RS485), the set mode will be active 10 seconds after power up.

ALIGNMENT OF THE INSTRUMENT

The instrument is equipped with a magnetic compass, and wind speed and direction measurements are automatically compensated and referred to as magnetic North, even if alignment to North is not performed. This allows for obtaining accurate measurements even in case of mobile installations.
It is possible to disable the compass compensation of the wind speed and direction measurements. 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 PC (see following chapters for communication 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 the 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.

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 the numbers and function of the connector contacts and the corresponding wires of the optional CP52.x cable:

TAB. 5.A – Electrical connections

Connector pin N o| CP52.x cable wire N o /color| Symbol| Description
---|---|---|---
1| | | Not used
2| 2 / Blue| RX SDI| Data line for SDI-12 connection
3| 3 / Yellow| RX +| Serial receive (input) positive
4| | HEAT –| Heater power supply negative
5| | HEAT +| Heater power supply positive (10…30 Vdc)
6| 6 / Pink| HEAT –| Heater power supply negative
7| 7 / Violet| HEAT +| Heater power supply positive (10…30 Vdc)
8| 8 / Grey| GND| Serial ground
9| 9 / White| TX –| Serial transmission (output) negative “DATA –” RS485 output
10| | | Not used
11| | | Not used
12| 12 / Black| V –| Instrument power supply negative
13| 4 / Grey-Pink| RX –| Serial receive (input) negative
14| 10 / Brown| OUT 1| Analog output 1 positive
15| | GND| Analog ground (isolated from V –)
16| 11 / Green| OUT 2| Analog output 2 positive
17| 5 / Red-Blue| TX +| Serial transmission (output) positive “DATA +” RS485 output
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

ATTENTION: The optional 12-pole CP52.x cable wire number does not always coin- cide with the M23 connector pin number.
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 PC (pin 2, 3 and 5 of 9-pole SubD connector). The length of RS232 cables should not exceed 15 m.
With RS232 connection, NMEA, MODBUS-RTU, and proprietary RS232 protocols can be used.
If the PC is not equipped with RS232 serial ports, the RS52 adapting cable (with built-in USB/RS232 converter) can be inserted between the PC and the instrument (see paragraph 5.2.6).
RS485 SERIAL CONNECTION 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 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.
NMEA, MODBUS-RTU and proprietary RS485 protocols can be used with RS485 connection.
Before connecting the instrument to the network, configure address and Baud Rate (see chap-ter 6 “CONFIGURATION”).
RS422 SERIAL CONNECTION

RS422 standard is used for point-to-point connection on long distances. The instrument is con-nected to a PC/data logger through a shielded cable with two twisted pairs for signals and an additional wire for ground. The extremities of the connections should end with line terminators.
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 lines should be kept separated from any power lines in order to prevent interference with the transmitted signal.
NMEA, MODBUS-RTU and proprietary RS485 protocols can be used with RS422 connection.
Before connecting the instrument to the network, configure the address and Baud Rate (see chap-ter 6 “CONFIGURATION”).
SDI-12 SERIAL CONNECTION

SDI-12 standard has three connection wires: power supply +12V, data line and ground.
Up to 10 sensors can be connected in parallel, each of them identified by its own address. Communication between sensors and PC/datalogger is performed at 1200 baud. Connection cables should not exceed 60 m.
The instrument should be configured to operate in SDI-12 mode. Set the address (see chapter 6 “CONFIGURATION”) before connecting the instrument to the network.
ANALOG OUTPUTS CONNECTION
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”. CONNECTION OF RS52 CABLE
If the PC is not equipped with RS232 serial ports, but with USB ports only, the RS52 adapting cable (with built-in USB/RS232 converter) should be interposed between the PC and the instrument. To use the RS52 cable, the drivers included in the HD52.3D-S software package should be installed in the PC (see the guide to USB drivers installation included in the software package). The instrument is powered directly from the USB port of the PC.
CONNECTION OF HEATING SYSTEM
Models with heat option (R option) have an integrated device that heats sonic transducers in order to prevent ice forming and ensure correct operation even in the presence of snow.
The heater power supply is separated from the instrument’s main power supply .Heating needs 10…30 Vdc power supply and 6 W power. The heat circuit is switched on below +4 °C. After switching on, the heating is switched off when the temperature exceeds +8 °C.

CONFIGURATION

Configuration mode allows to read the instrument’s general info (firmware version, calibration date, serial number), to set the operation mode, to read and set the instrument operation pa-rameters.
To configure the instrument, a RS232 serial connection to a PC should be performed (see paragraph 5.2.1). If your PC is not equipped with RS232 serial ports, the RS52 adapting cable can be placed between the PC and the instrument (see paragraph 5.2.6).
Communication parameters should be set in the PC as follows

• Baud rate: 115200
• Data Bits: 8
• Parity: None
• Stop Bit: 2

The instrument configuration can be realized with the aid of the HD52.3D-S application soft-ware (see the instructions of the software) or by sending serial commands via standard com-munication programs.
The configuration procedure by sending serial commands slightly differs depending on whether the instrument is set in configuration mode (factory setting, unless otherwise requested), or whether it is set in one of the available operation modes (SDI-12, NMEA, MODBUS-RTU, pro-prietary RS232, proprietary RS485).
INSTRUMENT SET IN CONFIGURATION MODE (factory setting)
If the instrument is set in configuration mode, at power-up it remains waiting to receive the configuration serial commands described in the following tables. To configure and make the in-strument operational, the following should be performed:

• Send command for operation mode selection (see table Operation Mode described at paragraph 6.1 “Serial Commands”).
• Send commands to set the parameters of the selected operation mode (see tables de-scribed at paragraph 6.1 “Serial Commands”).
• Send commands to set operational general parameters (parameters independent from operation mode)
• Turn the instrument off and on. The selected operation mode will become active after 10 seconds from restart.
  Note: configuration commands can be sent in any order; it is not necessary to respect the indicated sequence.

INSTRUMENT SET IN ONE OF THE AVAILABLE OPERATION MODES
If the instrument is set in one of the available operation modes, when started up it remains waiting for a serial command for 10 seconds. For instrument configuration, the following should be performed:

• Send the following command to the instrument before 10 seconds have elapsed:
  @
  with = ASCII character Carriage Return.
  If the instrument doesn’t receive the over-mentioned command after 10 seconds from start up, the operation mode set in the instrument is immediately activated.

• Send commands to change the desired parameters (see tables described at paragraph 6.1 “Serial Commands”).

• Turn the instrument off and on. The selected operation mode will become active after 10 seconds from restart with the new parameter values.

SERIAL COMMANDS

The tables below describe the serial commands that allow to read the current instrument con-figuration and change the operation parameters.
Measuring units:

§  m/s if n=1

§  cm/s if n=2

§  km/h if n=3

§  knot if n=4

§  mph if n=5

Default : m/s (n=1)

RGUV| n|| Reads the wind speed measuring unit set in the instrument
CGUTn| &|| Sets temperature measuring unit:

§  °C if n=1

§  °F if n=2

Default : °C (n=1)

RGUT| n|| Reads the temperature measuring unit set in the instrument
CGUPn| &|| Sets pressure measuring unit:

§  mbar if n=1      [Note:1 mbar=1 hPa]

§  mmHg if n=2

§  inchHg if n=3

§  mmH2O if n=4

§  inchH2O if n=5

§  atm if n=6

Default : mbar (n=1)

RGUP| n|| Reads the pressure measuring unit set in the instrument
CGURn| &|| Sets rainfall measuring unit:

§  mm if n=1

§  inch if n=2

Default : mm (n=1)

RGUR| n|| Reads the Rainfall measuring unit set in the instrument

Operation Mode:

§  Configuration if n=0

§  proprietary RS485 if n=1

§  proprietary RS232 if n=2

§  SDI-12 if n=3

§  NMEA if n=4

§  MODBUS-RTU if n=5

Default : Configuration (n=0)

RUM| & n|| Reads mode set in the instrument

Note 1: after sending the command for the selection of the operation mode, the instrument remains in configuration mode. The selected mode will become active at the following restart of the instrument.
Parameters for proprietary RS232 and RS485 modes:

The address is an alphanumeric character ranging within 0…9, a…z, A…Z

Default : 0

RU1A| & c|| Reads the address for proprietary RS485 mode set in the instrument
CU1Bn| &|| Sets Baud Rate for proprietary RS485 mode to:

§  9600 if n=3

§  19200 if n=4

§  38400 if n=5

§  57600 if n=6

§  115200 if n=7

Default : 115200 (n=7)

RU1B| & n|| Reads Baud Rate setting for proprietary RS485 mode
CU2Bn| &|| Sets Baud Rate for proprietary RS232 mode to:

§  9600 if n=3

§  19200 if n=4

§  38400 if n=5

§         57600 if n=6

Default : 57600 (n=6)

RU2B| & n|| Reads Baud Rate setting for proprietary RS232 mode
CU1Dccccccccccc| &|| Sets measurements order in the string sent in proprietary RS232 and RS485 modes

In the sequence ccccccccccc (max. 11 characters) each character identifies a measurement according to the following correspondence:

0  Þ Barometric Pressure

1  Þ Temperature (sensor Pt100) 2 Þ Relative Humidity

3 Þ Pyranometer

6 Þ Wind speed (coordinates U,V) 7 Þ Wind speed (intensity)

8 Þ Wind Direction (Azimuth) T Þ Sonic Temperature

C Þ Compass E Þ Errors

note: the Wind Gust measurement and the rainfall measurement are not available in proprietary RS232 and RS485 modes

Default : 78

(see Note 2 )

RU1D| & ccccccccccc|| Reads measurements order in the string sent in proprietary RS232 and RS485 modes
Command| Reply| Description
---|---|---
CU2Rnnnn| &|| Sets transmission interval of string with measurements in proprietary RS232 mode to nnnn seconds

The interval should range within 1 and 3600 seconds

Default : 1 second

RU2R| & nnnn|| Reads transmission interval of string with measurements in proprietary RS232 mode

NOTE 2 : MEASUREMENTS ORDER
In the measurement string sent by the instrument (constantly in proprietary RS232 mode, on request in proprietary RS485 mode), measurements can be set in arbitrary order: one should simply indicate the desired order in the sequence of characters “ccc ccc ccc” sent by the command C1UD. The sequence of characters “ccc ccc ccc” can have a variable length up to a maximum of 11 characters.
Example: if the sequence of characters is set to 78012, wind speed, wind direction, barometric pressure, temperature and relative humidity measurements will appear from left to right in the data string sent by the instrument.
If the information on error conditions is requested (E character), three numbers with the following meaning will appear in the data string sent by the instrument:

1. First number = error code identifying the transducers and the type of error.
   The number is composed by two digits. The first digit indicates the path (that is the pair of the transducers) that presents the error, according to the numeration indicated in the figure:Digit 7 indicates an error in the compass. Digit 0 indicates that no errors are present in the ultrasonic transducers or in the compass.
   The second digit of the error code indicates the type of error: 0 = no errors; 1 = transducer broken, electric interruption, path obstruction; Other = codes re-served to technical service.

2. Second number = state of activation of the ultrasonic transducers heating.
   0 = heating turned off, 1 = heating turned on

3. Third number = number of invalid measurements.
   For example: if 21 0 2 appears in correspondence to the error condition in the data string sent by the instrument, it means that an error occurred (broken transducer or path obstruction) in the path number 2, that the heating is turned off and that two measurements have been rejected due to the error occurrence.

Parameters for NMEA mode:

§ 2400 if n=1

§ 4800 if n=2

§ 9600 if n=3

§ 19200 if n=4

§ 38400 if n=5

§ 57600 if n=6

§ 115200 if n=7

Default : 4800 (n=2)

RU4B| & n|| Reads Baud Rate setting for NMEA mode
CU4In| &|| Sets interface for NMEA mode to:

§ RS232 if n=0

§ RS485 if n=1

§ RS422 if n=2

Default : RS485 (n=1)

RU4I| & n|| Reads interface setting for NMEA mode
CU4Mn| &|| Sets parity and stop bits for NMEA mode to:

§  8N1 if n=0 [No parity, 1 stop bit]

§  8N2 if n=1 [No parity, 2 stop bits]

§  8E1 if n=2 [Even parity, 1 stop bit]

§  8E2 if n=3 [Even parity, 2 stop bits]

§  8O1 if n=4 [Odd parity, 1 stop bit]

§  8O2 if n=5 [Odd parity, 2 stop bits] The number of data bits is fixed to 8

Default : 8N1 (n=0)

RU4M| & n|| Reads current setting of parity and stop bits for NMEA mode
CU4Rnnn| &|| Sets transmission interval of a string with measurements in NMEA mode to nnn seconds

The interval should range between 1 and 255 seconds

Default : 1 second

RU4R| & nnn|| Reads setting of the transmission interval of string with measurements in NMEA mode

Parameters for MODBUS-RTU mode:

The address should range between 1 and 247

Default : 1

RU5A| & nnn|| Reads the MODBUS address setting
CU5Bn| &|| Sets the Baud Rate for MODBUS mode to:

§ 9600 if n=3

§ 19200 if n=4

§ 38400 if n=5 (from firmware vers. 2.21)

§ 57600 if n=6 (from firmware vers. 2.21)

§ 115200 if n=7 (from firmware vers. 2.21)

Default : 19200 (n=4)

RU5B| & n|| Reads Baud Rate setting for MODBUS mode
CU5In| &|| Sets interface for MODBUS mode to:

§ RS232 if n=0

§ RS485 if n=1

§ RS422 if n=2

Default : RS485 (n=1)

Note: with RS232 option you can connect to PC or datalogger 1 instrument only; option useful to do tests without RS232/RS485 conversion.

RU5I| & n|| Reads interface setting for MODBUS mode
CU5Mn| &|| Sets parity and stop bits for MODBUS mode to:

§ 8N1 if n=0 [No parity, 1 stop bit]

§ 8N2 if n=1 [No parity, 2 stop bits]

§ 8E1 if n=2 [Even parity, 1 stop bit]

§ 8E2 if n=3 [Even parity, 2 stop bits]

§ 8O1 if n=4 [Odd parity, 1 stop bit]

§ 8O2 if n=5 [Odd parity, 2 stop bits] The number of bits is fixed to 8

Default : 8E1 (n=2)

RU5M| & n|| Reads the setting of parity and stop bits for MODBUS mode
CU5Wn| &|| Sets waiting time after transmission in MODBUS mode to:

§ Immediate reception if n=0 (violates protocol)

§ Waiting 3.5 characters if n=1 (respects protocol)

Default : Waiting 3.5 characters (n=1)

RU5W| & n|| Reads the setting of waiting time after transmission in MODBUS mode

Parameters for SDI-12 mode:

The address is an alphanumeric character ranging within 0…9, a…z, A…Z. Default : 0

RU3A| & c|| Reads the SDI-12 address set in the instrument

General parameters:

– Disables if n=0                   – Enables if n=1

Default : Enabled (n=1)

RGH| n|| Reads heating enabling state set in the in- strument
CWCnnnn| &|| Sets wind speed threshold to nnnn value (in hundredths of m/s)

Value should range within 0 and 100 hun- dredths of m/s (= 0…1 m/s)

Default : 20 (= 0.2 m/s)

(see Note 3 )

RWC| & nnnn|| Reads the wind speed threshold value set in the instrument (in hundredths of m/s)
CWaLnnn| &|| Sets time interval for the calculation of aver- age speed and average direction to nnn value

Value should range within 1 and 600 s.

If the value is greater than 10 s, it must be an integer multiple of 10.

note:the value can be greater than or equal to 10 s starting from firmware version 2.20

Default : 1 s

RWaL| & nnn|| Reads the time interval for the calculation of average speed and average direction set in the instrument
CWaMn| &|| Sets the method for the calculation of average speed and average direction:

§  If n=0: scalar mean. The average inten- sity is calculated as average of intensities without consideration of direction. The average direction is calculated as average of directions, and expressed according to the extended characteristic (see Note 4 ).

§  If n=1: vector mean. The average of the coordinates along each measurement axis is calculated. The average intensity and the average direction are those deter- mined by the two average coordinates.

Default : vector mean (n=1)

average direction set in the instrument
CCn

note: command available from firmware version 2.06

| &|| Enables/disables the compass compensation of wind speed and direction:

– Disables if n=N                   – Enables if n=Y

Default : Enabled (n=Y)

CRTnnnn| &|| Sets the resolution of the rain gauge tipping bucket to nnnn value (in µm)

Value should range within 50 and 1599 µm

Default : 200 (= 0.200 mm)

RRT| & nnnn|| Reads the rain gauge resolution value set in the instrument (in µm)

NOTE 3 : WIND SPEED THRESHOLD VALUE
If the wind speed is very low, the determination of the direction can result inaccurate. The instrument allows setting the threshold value of speed below which the direction value is frozen on the last acquired value.
NOTE 4 : WIND DIRECTION EXTENDED CHARACTERISTIC
With 0÷359.9° wind direction measuring range, the analog output continues to oscillate between maximum and minimum scale if the direction continues to slightly fluctuate around 0°:This effect can be reduced through the extended (“wrap-around”) characteristic of wind direction. In this mode, the wind direction is considered as corresponding to a 0÷539.9° range instead of 0÷359.9°. The wide output fluctuation occurs the first time that the wind direction goes from 0 to 359.9°; if later the “physical” direction goes back to 0°, the analog output will always remain around 360°. Using the extended characteristic, the behavior of the above graph changes into the following :If 539.9° value is exceeded in extended mode, the output goes to the value corresponding to 180°.
The table below shows the correspondence between the value of the analog output and the di-rection of the wind in the two modes.

Wind direction| 4…20mA output| 0…1V output| 0…5V output| 0…10V output
---|---|---|---|---
standard| extended| standard| extended| standard| extended| standard| extended
0°| 4.00| 4.00| 0.00| 0.00| 0.00| 0.00| 0.00| 0.00
180°| 12.00| 9.33| 0.50| 0.33| 2.50| 1.67| 5.00| 3.33
360°| 20.00| 14.67| 1.00| 0.67| 5.00| 3.33| 10.00| 6.67
540°| —| 20.00| —| 1.00| —| 5.00| —| 10.00

Analog outputs:

§  Standard if nn=00

[ ex. 4…20 mA , 0…1 V , 0…5 V , 0…10 V ]

§  Without offset if nn=01

[ ex. 0…20 mA ]

§  With offset if nn=02

[ ex. 0.2…1 V , 1…5 V , 2…10 V ]

§  Inverted if nn=04

[ ex. 20…4 mA , 1…0 V , 5…0 V , 10…0 V ]

§  Inverted without offset if nn=05

[ ex. 20…0 mA ]

§  Inverted with offset if nn=06

[ ex. 1…0.2 V , 5…1 V , 10…2 V ]

Default : Standard (nn=00)

RAFx| & nn|| Reads offset and direction setting of the analog output x (x=1 or 2)
CAMn| &|| Association of the analog outputs:

§  If n= 0:

Output 1 = Mean wind speed Output 2 = Mean wind direction

§  If n= 1 (see Note 5 ):

Output 1 = Instant wind speed component along V-axis

Output 2 = Instant wind speed component along U-axis

§  If n= 2 ( Tunnel mode, see Note 6 ):

Output 1 = Instant wind speed component along the direction indicated by the arrow on the instrument case

Output 2 = Instant wind direction referred to the direction indicated by the arrow on the instrument case

Default : n=0

RAM| & n|| Reads the association of analog outputs
CAHn| &|| Associates full scale of wind speed analog output to:

§  5 m/s if n=0                 § 50 m/s if n=9

§ 10 m/s if n=1                 § 55 m/s if n=10

§ 15 m/s if n=2                 § 60 m/s if n=11

§ 20 m/s if n=3                 § 65 m/s if n=12

§ 25 m/s if n=4                 § 70 m/s if n=13

§ 30 m/s if n=5                 § 75 m/s if n=14

§ 35 m/s if n=6                 § 80 m/s if n=15

§ 40 m/s if n=7                 § 85 m/s if n=16

§ 45 m/s if n=8                 § 90 m/s if n=17

Default : 60 m/s (n=11)

scale

By selecting the U and V components, the speed value associated to the initial scale of the two analog outputs is equal to the opposite of the speed value associated to the full scale of the outputs.
For example, if the speed full-scale value is set to 60 m/s, the speed range associated to the analog outputs is -60…+60 m/s.
NOTA 6: TUNNEL MODE
In tunnel mode, the wind direction measurement is not compensated by the magnetic compass, but the measurement is referred to the direction indicated by the arrow on the instrument case.
Output 2 is set to full-scale value if the wind blows in the direction of the arrow, and to initial scale value if the wind blows in the opposite direction.
The initial scale of output 1 is associated to the speed value opposite to that associated to the output full scale.
The arrow on the instrument case should be aligned with the direction of the tunnel.

Instrument information

PROPRIETARY RS232 MODE

In proprietary RS232 mode, the instrument sends automatically the acquired measurements at regular intervals. The interval is factory-set to 1 second and is configurable from 1 to 3600 seconds. To change the interval, you should enter in configuration mode and send the com-mand CU2Rnnnn, where nnnn indicates the interval value in seconds (see chapter 6 “CON-FIGURATION” for details regarding the setting of operation parameters).
To use this mode, you must connect to a RS232 serial port. Communication parameters should be set in your PC as follows:

• Baud rate: 9600 to 57600 (same as the setting in the instrument)
• Data bits: 8
• Parity: None
• Stop bits: 2

The instrument sends measurements in the following format: with …. = values of the first, second,…., nth measurement = ASCII character Carriage Return = ASCII character Line Feed
Fields …. consist of 8 characters each. Measurement values are justified right; spaces can be added to the left margin of the values to obtain the 8 character length re-quested by the fields.
The sequence of the measurement values …. is configurable (see chapter 6 “CONFIGURATION”).
EXAMPLE
Supposing that the instrument measures the following values (the measuring unit is not considered, being not output by the instrument): M1=2.23, M2=-28.34, M3=0.34, M4=28.30, M5=359.3, M6=-1.3, the data string sent by the instrument takes the form:
2.23 -28.34 c 0.34 28.30 359.3 -1.3

PROPRIETARY RS485 MODE

In proprietary RS485 mode, the instrument sends the acquired measurements only if requested by the PC.
To use this mode, you must connect to an RS485 or RS422 serial port. Communication parameters should be set in the PC or data logger as follows:

• Baud rate: 9600 to 115200 (same as the setting in the instrument)
• Data bits: 8
• Parity: None
• Stop bits: 2

The instrument is requested to send measurements by generating a Break Signal (*) on the serial line for at least 2 ms, and then sending the following command, consisting of 4 ASCII characters:
M