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Vaisala WXT510 User Manual

Vaisala WXT510 User Manual

Weather transmitter
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USER'S GUIDE
Vaisala Weather Transmitter
WXT510
M210470EN-D

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Summary of Contents for Vaisala WXT510

  • Page 1 USER'S GUIDE Vaisala Weather Transmitter WXT510 M210470EN-D...
  • Page 2 The contents are subject to change without prior notice. Please observe that this manual does not create any legally binding obligations for Vaisala towards the customer or end user. All legally binding commitments and agreements are included exclusively in the...

  • Page 3: Table Of Contents

    Selecting Location ....... . 27 Assembling WXT510 ....... 28 Installation Procedure .
  • Page 4 ________________________________________________________________________________ CHAPTER 5 WIRING AND POWER MANAGEMENT ......35 Power Supplies ........35 Wiring Using the Screw Terminals .
  • Page 5 Factory Calibration and Repair Service ....115 Vaisala Service Centers ......115...
  • Page 6 ________________________________________________________________________________ CHAPTER 10 TROUBLESHOOTING ........117 Self-Diagnostics .
  • Page 7 Service Cable (Optional) ......19 Figure 7 Assembling WXT510 ....... . 28 Figure 8 Location of Fixing Screw .
  • Page 8 ________________________________________________________________________________ 6 _______________________________________________________________________________...
  • Page 9 Power Supplies ........38 Table 2 Pin-outs for WXT510 Serial Interfaces and Power Supplies ..39 Table 3 Available Serial Communication Protocols .
  • Page 10 ________________________________________________________________________________ 8 _______________________________________________________________________________...

  • Page 11: Chapter 1 General Information

    Transmitter WXT510. Chapter 4, Installation: This chapter provides you with information that is intended to help you install Weather Transmitter WXT510. Chapter 5, Wiring and Power Management: This chapter provides you with instructions on how to connect the power supply and the serial interfaces.

  • Page 12: Feedback

    ASCII, NMEA 0183 and SDI-12. Chapter 9, Maintenance: This chapter contains instructions for the basic maintenance of Weather Transmitter WXT510 and contact information for Vaisala Service Centers. Chapter 10, Troubleshooting: This chapter describes common problems, their probable causes and remedies, and includes contact information for technical support.

  • Page 13: Esd Protection

    Note highlights important information on using the product. ESD Protection Electrostatic Discharge (ESD) can cause immediate or latent damage to electronic circuits. Vaisala products are adequately protected against ESD for their intended use. However, it is possible to damage the product by delivering electrostatic discharges when touching, removing, or inserting any objects inside the equipment housing.

  • Page 14: Trademarks

    Microsoft Corporation in the United States and/or other countries. License Agreement All rights to any software are held by Vaisala or third parties. The customer is allowed to use the software only to the extent that is provided by the applicable supply contract or Software License Agreement.

  • Page 15: Warranty

    The allegedly defective Product or part shall, should Products supplied hereunder, which obligations and Vaisala so require, be sent to the works of Vaisala or to liabilities are hereby expressly cancelled and waived. such other place as Vaisala may indicate in writing,...
  • Page 16 User’s Guide ______________________________________________________________________ 14 __________________________________________________________________ M210470EN-D...

  • Page 17: Chapter 2 Product Overview

    Chapter 2 __________________________________________________________ Product Overview CHAPTER 2 PRODUCT OVERVIEW This chapter introduces the unique features and advantages of the Vaisala Weather Transmitter WXT510. Weather Transmitter WXT510 Figure 1 Vaisala Weather Transmitter WXT510 0504-066 VAISALA _______________________________________________________________________ 15...

  • Page 18: Optional Software For Easy Settings

    WXT510 powers up with 5 ... 30 VDC and outputs serial data with a selectable communication protocol: SDI-12, ASCII automatic & polled and NMEA 0183 with query option. Four alternative serial interfaces are selectable: RS-232, RS-485, RS-422 and SDI-12.

  • Page 19: Wxt510 Transmitter Components

    Chapter 2 __________________________________________________________ Product Overview WXT510 Transmitter Components Figure 2 Main Components of Weather Transmitter WXT510 0505-190 The following numbers refer to Figure 2 on page Top of the transmitter Radiation shield Bottom of the transmitter Screw cover VAISALA _______________________________________________________________________ 17...

  • Page 20: Figure 3 Cut Away View

    User’s Guide ______________________________________________________________________ Figure 3 Cut Away View 0505-191 The following numbers refer to Figure 3 on page Wind transducers (3 pcs) Precipitation sensor Pressure sensor inside the PTU module Humidity and temperature sensors inside the PTU module Figure 4 Bottom of Transmitter 0505-192 18 __________________________________________________________________ M210470EN-D...

  • Page 21: Figure 5 Mounting Kit (Optional)

    Water tight cable gland (shown disassembled) Opening for cable gland (if unused, cover with hexagonal plug) 8-pin M12 connector for power/datacom cable (optional, cover with hexagonal plug if unused) Figure 5 Mounting Kit (Optional) 0505-193 Figure 6 Service Cable (Optional) 0505-194 VAISALA _______________________________________________________________________ 19...
  • Page 22 Figure 6 on page Battery connector D9-connector for PC serial port Connector for WXT510 service port (press the white flap while disconnecting cable) The service cable, while connected between the service port and PC, forces the service port to RS-232 / 19200, 8, N, 1.

  • Page 23: Functional Description

    Chapter 3 ______________________________________________________ Functional Description CHAPTER 3 FUNCTIONAL DESCRIPTION This chapter describes the measurement principles and heating function of Weather Transmitter WXT510. Wind Measurement Principle ® WXT510 uses Vaisala WINDCAP sensor technology in wind measurement. The wind sensor has an array of three equally spaced ultrasonic transducers on a horizontal plane.
  • Page 24 The wind speed is represented as a scalar speed in selected units (m/s, kt, mph, km/h). The wind direction is expressed in degrees (°). The wind direction reported by WXT510 indicates the direction that the wind comes from. North is represented as 0°, east as 90°, south as 180°, and west as 270°.

  • Page 25: Precipitation Measurement Principle

    Chapter 3 ______________________________________________________ Functional Description Precipitation Measurement Principle ® WXT510 uses Vaisala RAINCAP Sensor 2-technology in precipitation measurement. The precipitation sensor comprises of a steel cover and a piezoelectrical sensor mounted on the bottom surface of the cover. The precipitation sensor detects the impact of individual raindrops. The signals from the impact are proportional to the volume of the drops.

  • Page 26: Ptu Measurement Principle

    User’s Guide ______________________________________________________________________ Time mode: Transmitter sends automatically a precipitation message in the update intervals defined by the user. Polled mode: Transmitter sends a precipitation message whenever requested by the user. More information about the precipitation sensor operation modes can be found in section Precipitation Sensor on page 103.
  • Page 27 -4 °C < Th < 0 °C: 100 % heating power, Th < -4 °C: 50 % heating power. When the heating function is disabled the heating is off in all conditions, Supervisor Message on page 108. VAISALA _______________________________________________________________________ 25...
  • Page 28 User’s Guide ______________________________________________________________________ 26 __________________________________________________________________ M210470EN-D...

  • Page 29: Chapter 4 Installation

    WARNING To protect personnel (and the device), a lightning rod should be installed with the tip at least one meter above WXT510. The rod must be properly grounded, compliant with all applicable local safety regulations. VAISALA _______________________________________________________________________ 27...

  • Page 30: Assembling Wxt510

    User’s Guide ______________________________________________________________________ Assembling WXT510 Loosen the three fixing screws at the sensor bottom assembly. Turn out the top of the transmitter. Remove the vacuum bag protecting the PTU module. Connect the new PTU module. Make sure the module goes all the way in and is...

  • Page 31: Installation Procedure

    Chapter 4 _______________________________________________________________ Installation Installation Procedure At the measurement site, WXT510 needs to be mounted, aligned, and connected to the data logger and the power source. Mounting Weather Transmitter WXT510 can be mounted either onto a vertical pole mast or onto a horizontal cross arm. When mounting WXT510 onto a pole mast, an optional mounting kit can be used to ease mounting.

  • Page 32: Mounting With Mounting Kit (Optional)

    Figure 9 on page Mounting kit Fixing screw NOTE When removing WXT510 from the pole just turn the transmitter so that it snaps out from the mounting kit. When replacing the device the alignment is not needed. 30 __________________________________________________________________ M210470EN-D...

  • Page 33: Mounting To Horizontal Cross Arm

    (M6 DIN933) and a nut, see Figure 9 on page 30 Figure 10 on page Figure 10 Mounting WXT510 to Cross Arm (L-Profile) 0505-199 The following numbers refer to Figure 10 on page Fixing screw (M6 DIN933) VAISALA _______________________________________________________________________ 31...

  • Page 34: Aligning Wxt510

    Aligning WXT510 To help the alignment, there is an arrow and the text "North" on the bottom of the transmitter. WXT510 should be aligned in such a way that this arrow points to the north. Wind direction can be referred either to true north, which uses the earth’s geographic meridians, or to the magnetic north, which is read...

  • Page 35: Compass Alignment

    Compass Alignment To align Weather Transmitter WXT510, proceed as follows: If WXT510 is already mounted, loosen the fixing screw on the bottom of the transmitter so that you can rotate the device. Use a compass to determine that the transducer heads of WXT510 are exactly in line with the compass and that the arrow on the bottom of WXT510 points to the north.

  • Page 36: Wind Direction Correction

    User’s Guide ______________________________________________________________________ Wind Direction Correction Make a wind direction correction in case WXT510 cannot be aligned in such a way that the arrow on the bottom points to the north. In this case, the deviation angle from the true north should be given to WXT510.

  • Page 37: Wiring And Power Management

    This chapter provides you with instructions on how to connect the power supply and the serial interfaces. WXT510 can be accessed through four different serial interfaces: RS- 232, RS-485, RS-422 and SDI-12. Each of them can be wired either through the internal screw terminal or the 8-pin M12 connector (optional).

  • Page 38: Figure 14 Average Operational Current Consumption

    12 VDC ± 20 % (max 1.1 A); 24 VDC ± 20 % (max 0.6 A). At approximately 16 V heating voltage level WXT510 automatically changes the heating element combination in order to consume equal power with 12 VDC and 24 VDC supplies. Input resistance (R ) is radically increased with voltages above 16 V (see the following graph).

  • Page 39: Wiring Using The Screw Terminals

    Make sure that you connect only de-energized wires. Wiring Using the Screw Terminals Loosen the three long screws at the bottom of WXT510. Pull out the bottom part of the transmitter. Insert the power supply wires and signal wires through the cable gland(s) in the bottom of the transmitter.

  • Page 40: Figure 16 Screw Terminal Block

    Vin+ (operating) NOTE In the true SDI-12 mode the two Data in/out lines must be combined either in the screw terminal or outside WXT510. NOTE Short-circuit jumpers are required between pins 1-3 and 2-4 for the RS-485 communication mode. For the RS-422 mode, the jumpers should be removed.

  • Page 41: Wiring Using The 8-Pin M12 Connector (Optional)

    Chapter 5 _______________________________________________ Wiring and Power Management Wiring Using the 8-pin M12 Connector (Optional) External Wiring If WXT510 is provided with the optional 8-pin M12 connector, the connector is located on the bottom of the transmitter, see Figure 4 on page 18.

  • Page 42: Internal Wiring

    (outside WXT510). See the interface diagrams in the next section. Bidirectional use of the RS-485 and RS-422 interface requires a proper adapter module between the PC and WXT510. For testing purposes, the inverted output of either interface (screw terminal pin #3 TX-) is 40 __________________________________________________________________ M210470EN-D...

  • Page 43: Data Communication Interfaces

    For configuration work, the Service Port is most practical, since it has constant and convenient line parameters: RS232/19200, 8, N, 1. See Chapter 6, Communication Settings, on page 45 Figure 4 on page 18). Data Communication Interfaces Figure 19 Data Communication Interfaces 0505-206 VAISALA _______________________________________________________________________ 41...

  • Page 44: Power Management

    100 m (300 ft) with 1200 Bd data rate. Higher rates require shorter distance, for instance 30 m (100 ft) with 9600 Bd. NOTE When WXT510 is used on an RS-485 bus with other polled devices, the error messaging feature shall always be disabled. This is done by the following command: 0SU,S=N<crlf>.
  • Page 45 On the other hand, the RS-485 driver is in high impedance state when not transmitting - thus in idle state no current can be drawn by the host input. NMEA modes consume about the same as ASCII modes. VAISALA _______________________________________________________________________ 43...
  • Page 46 NOTE While in Service mode and/or while supplied through the Service port the WXT510 consumes 0.5 ... 1 mA more than in normal mode, supplied through the Main port (M12 connector or screw terminals). When supplied through the Service port the minimum voltage level for reliable operation is 6V.

  • Page 47: Communication Settings

    This chapter contains the instructions for making the communication settings. Communication Protocols As soon as WXT510 has been properly connected and powered the data transmission can be started. The communication protocols available in each of the serial interfaces are shown in the following table.

  • Page 48: Service Cable Connection

    (see Figure 4 on page 18) by using the service cable. Power-up WXT510 with a 9 V battery attached to the service cable or by using the screw terminals/M12 connector. Open the Vaisala Configuration Tool/terminal program. Select the following default communication settings: 19200, 8, N, 1.

  • Page 49: Terminal

    Serial Interface Serial Settings SDI-12 1200 baud, 7, E, 1 RS-232, ASCII 19200 baud, 8, N, 1 RS-485, ASCII 19200 baud, 8, N, 1 RS-422 ASCII 19200 baud, 8, N, 1 RS-422 NMEA 4800 baud, 8, N, 1 VAISALA _______________________________________________________________________ 47...

  • Page 50: Communication Setting Commands

    Checking the Current Communication Settings (aXU) With this command you can request the current communication settings of WXT510. Command format in ASCII and NMEA 0183: aXU<cr><lf> Command format in SDI-12: aXXU! where Device address, which may consist of the following characters: 0 (default) ...

  • Page 51: Setting Fields

    Automatic repeat interval for Composite data message:1 ... 3600 s, 0 = no automatic repeat Baud rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 Data bits: 7/8 Parity: O = Odd, E = Even, N = None Stop bits: 1/2 VAISALA _______________________________________________________________________ 49...
  • Page 52 RS-485 line delay: 0 ... 10000 ms Defines the delay between the last character of the query and the first character of the response message from WXT510. During the delay, the WXT510's transmitter is disabled. Effective in ASCII, polled and NMEA 0183 query protocols. Effective when RS-485 is selected (C = 3).

  • Page 53: Changing The Communication Settings

    1200, 7, E, 1 and the communication protocol to SDI-12 (M=S). NOTE Reset the transmitter to validate the changes of communication parameters by disconnecting the service cable or using the Reset (aXZ) command, see Reset (aXZ) on page VAISALA _______________________________________________________________________ 51...
  • Page 54 1XU,A=1<cr><lf> Checking the changed settings: 1XU<cr><lf> 1XU,A=1,M=P,T=1,C=2,I=0,B=19200,D=8,P=N,S=1,L=25, N=WXT510,V=1.00<cr><lf> Example (ASCII, device address 0): Changing RS-232 serial interface with ASCII, polled communication protocol and baud settings 19200, 8, N, 1 to RS-485 serial interface with ASCII, automatic protocol and baud settings 9600, 8, N, 1.

  • Page 55: Getting The Data Messages

    General Commands In case the error messaging is disabled (see Supervisor Message on page 108), WXT510 does not return any response message with the general commands given in ASCII and NMEA-formats. Reset (aXZ) This command is used to perform software reset on the device.

  • Page 56: Precipitation Counter Reset (Axzru)

    User’s Guide ______________________________________________________________________ where Device address Reset command <cr><lf> Command terminator in ASCII and NMEA 0183 Command terminator in SDI-12 The response depends on the communication protocol, see the examples. Example (ASCII): 0XZ<cr><lf> 0TX,Start-up<cr><lf> Example (SDI-12): 0XZ!0<cr><lf> (=device address) Example (NMEA 0183): 0XZ<cr><lf>...

  • Page 57: Precipitation Intensity Reset (Axzri)

    The precipitation counter and precipitation intensity parameters are reset also when the supply voltage is disconnected, the command aXZ is issued, precipitation counter reset mode is changed or when the precipitation/surface hits units are changed. Example (ASCII): 0XZRI<cr><lf> VAISALA _______________________________________________________________________ 55...

  • Page 58: Measurement Reset (Axzm)

    User’s Guide ______________________________________________________________________ OTX,Inty reset<cr><lf> Example (SDI-12): 0XZRI!0<cr><lf> (= device address) Example (NMEA 0183): 0XZRI<cr><lf> $WITXT,01,01,11,Inty reset*39<cr><lf> Measurement Reset (aXZM) This command is used to interrupt all ongoing measurements of the transmitter and start them from the beginning. Command format in ASCII and NMEA 0183: aXZM<cr><lf> Command format in SDI-12: aXZM! where Device address...

  • Page 59: Ascii Protocol

    100% duty cycle and the heating temperature is between the low and middle control limits. F = heating is on at 50% duty cycle and the heating temperature is below the low control limit. VAISALA _______________________________________________________________________ 57...

  • Page 60: Device Address (?)

    User’s Guide ______________________________________________________________________ Device Address (?) This command is used to query the address of the device on the bus. Command format: ?<cr><lf> where Device address query command <cr><lf> Command terminator The response: b<cr><lf> where Device address (default = 0) <cr><lf>...

  • Page 61: Wind Data Message (Ar1)

    Device address Wind message query command Wind direction minimum (D = degrees) Wind direction average (D = degrees) Wind direction maximum (D = degrees) Wind speed minimum (M = m/s) Wind speed average (M = m/s) VAISALA _______________________________________________________________________ 59...

  • Page 62: Pressure, Temperature And Humidity Data Message

    User’s Guide ______________________________________________________________________ Wind speed maximum (M = m/s) <cr><lf> Response terminator To change the parameters and units in the response message and to make other sensor settings, see section Wind Sensor on page Pressure, Temperature and Humidity Data Message (aR2) With this command you can request a pressure, temperature and humidity data message.

  • Page 63: Precipitation Data Message (Ar3)

    Rain peak intensity (M = mm/h) Hail peak intensity (M = hits/cm <cr><lf> Response terminator To change the parameters or the units in the response message and to make other precipitation sensor settings, see section Precipitation Sensor on page 103. VAISALA _______________________________________________________________________ 61...

  • Page 64: Supervisor Data Message (Ar5)

    User’s Guide ______________________________________________________________________ Supervisor Data Message (aR5) With this command you can request a supervisor data message containing self-check parameters of the heating system and power supply voltage. Command format: aR5<cr><lf> where Device address Supervisor message query command <cr><lf> Command terminator Example of the response (the parameter set is configurable): 0R5,Th=25.9C,Vh=12.0N,Vs=15.2V,Vr=3.475V<cr><lf>...

  • Page 65: Composite Data Message Query (Ar0)

    Example of the response (the parameters included can be chosen from the full parameter set of the commands aR1, aR2, aR3 and aR5): 0R0,Dx=005D,Sx=2.8M,Ta=23.0C,Ua=30.0P,Pa=1028.2H, Hd=0.00M,Rd=10s,Th=23.6C<cr><lf> For selecting the parameter set in the response message, see Chapter 8, Sensor and Data Message Settings, on page VAISALA _______________________________________________________________________ 63...

  • Page 66: Polling With Crc

    User’s Guide ______________________________________________________________________ Polling with CRC Use the same data query commands as in the previous sections but type the first letter of the command in lower case and add a correct three- character CRC before the command terminator. The response contains also a CRC.

  • Page 67: Automatic Mode

    You can choose an individual update interval for each sensor, see Chapter 8, Sensor and Data Message Settings, on page 93, sections Changing the Settings. VAISALA _______________________________________________________________________ 65...

  • Page 68: Automatic Composite Data Message

    User’s Guide ______________________________________________________________________ Example: 0R1,Dm=027D,Sm=0.1M<cr><lf> 0R2,Ta=74.6F,Ua=14.7P,Pa=1012.9H<cr><lf> 0R3,Rc=0.10M,Rd=2380s,Ri=0.0M,Hc=0.0M,Hd=0s, Hi=0.0M<cr><lf> 0R5,Th=76.1F,Vh=11.5N,Vs=11.5V,Vr=3.510V<cr><lf> Example (with CRC): 0r1,Sn=0.1M,Sm=0.1M,Sx=0.1MGOG<cr><lf> 0r2,Ta=22.7C,Ua=55.5P,Pa=1004.7H@Fn<cr><lf> 0r3,Rc=0.00M,Rd=0s,Ri=0.0MIlm<cr><lf> 0r5,Th=25.0C,Vh=10.6#,Vs=10.8V,Vr=3.369VO]T<cr><lf> NOTE Stop the automatic output by changing the communication protocol to polled mode (aXU,M=P). Polling commands aR1, aR2, aR3, and aR5 can be used also in ASCII automatic protocol for requesting data.

  • Page 69: Sdi-12 Protocol

    This command is used to query the address of the device on the bus. If more than one sensor is connected to the bus, they will all respond, causing a bus collision. Command format: ?! where Address query command Command terminator VAISALA _______________________________________________________________________ 67...

  • Page 70: Acknowledge Active Command (A)

    User’s Guide ______________________________________________________________________ The response: a<cr><lf> where Device address (default = 0) <cr><lf> Response terminator Example (device address 0): ?!0<cr><lf> Acknowledge Active Command (a) This command is used to ensure that a device is responding to a data recorder or another SDI-12 device. It asks a device to acknowledge its presence on the SDI-12 bus.

  • Page 71: Change Address Command (Aab)

    Response terminator Example (changing address from 0 to 3): 0A3!3<cr><lf> Send Identification Command (aI) This command is used to query the device for the SDI-12 compatibility level, model number, and firmware version and serial number. Command format: aI! VAISALA _______________________________________________________________________ 69...

  • Page 72: Start Measurement Command (Am)

    User’s Guide ______________________________________________________________________ where Device address Send identification command Command terminator The response: a13ccccccccmmmmmmvvvxxxxxxxx<cr><lf> where Device address The SDI-12 version number, indicating SDI-12 version compatibility; for example, version 1.3 is encoded as 13 cccccccc 8-character vendor identification Vaisala_ mmmmmm = 6 characters specifying the sensor model number 3 characters specifying the firmware version xxxxxxxx...
  • Page 73 The measurement completing time in seconds The number of the measured parameters available (maximum number is 9) <cr><lf> Response terminator NOTE For changing the message parameters, units and other settings, see Chapter 8, Sensor and Data Message Settings, on page VAISALA _______________________________________________________________________ 71...

  • Page 74: Start Measurement Command With Crc (Amc)

    User’s Guide ______________________________________________________________________ NOTE When the measurement takes less than one second, the response part two is not sent. In WXT510 this is the case in the precipitation measurement aM3. NOTE The maximum number of parameters that can be measured with aM and aMC commands is nine (9).

  • Page 75: Start Concurrent Measurement With Crc (Acc)

    This command has the same function as aC but a three-character CRC is added to the response data strings before <cr><lf>. In order to request the measured data, Send data command aD should be used, see the following sections. VAISALA _______________________________________________________________________ 73...

  • Page 76: Send Data Command (Ad)

    User’s Guide ______________________________________________________________________ Send Data Command (aD) This command is used to request the measured data from the device. See Examples of aM, aC and aD Commands on page NOTE Start measurement command tells the number of parameters available. However, the number of the parameters that can be included in a single message depends on the number of characters in the data fields.

  • Page 77: Examples Of Am, Ac And Ad Commands

    Start a concurrent pressure, humidity and temperature measurement and request the data: 0C2!000503<cr><lf> (measurement ready in 5 seconds and 3 parameters available, for aC command device address not sent as a sign of a completed measurement) 0D0!0+23.6+29.5+1009.5<cr><lf> VAISALA _______________________________________________________________________ 75...
  • Page 78 User’s Guide ______________________________________________________________________ Example 3: Start a precipitation measurement and request the data: 0M3!00006<cr><lf> (6 parameters available immediately, thus the device address is not sent) 0D0!0+0.15+20+0.0+0.0+0+0.0<cr><lf> Example 4: Start a supervisor measurement with CRC and request the data: 0MC5!00014<cr><lf> (measurement ready in one second and 4 parameters available) 0<cr><lf>...

  • Page 79: Continuous Measurement (Ar)

    Chapter 8, Sensor and Data Message Settings, on page 93). NOTE For using Continuous measurement commands for all WXT510 parameters (wind, PTU, precipitation, and supervisor) the respective protocol must be selected (aXU,M=R). The M=S selection requires use of aM, aMC, aC, aCC + aD commands, only the precipitation data can be retrieved continuously (using aR3 command).

  • Page 80: Continuous Measurement With Crc (Arc)

    Example (device address 0): 0RC3!0+0.04+10+14.8+0.0+0+0.0INy Start Verification Command (aV) This command is used to query self diagnostic data from the device. However, the command is not implemented in WXT510. The self- diagnostic data can be requested with aM5 command. 78 __________________________________________________________________ M210470EN-D...

  • Page 81: Nmea 0183 V3.0 Protocol

    Response terminator. Example: ?<cr><lf> 0<cr><lf> If more than one transmitter is connected to the bus, see Appendix A, Networking, on page 131. If you need to change the device address, see Changing the Communication Settings on page VAISALA _______________________________________________________________________ 79...

  • Page 82: Acknowledge Active Command (A)

    User’s Guide ______________________________________________________________________ Acknowledge Active Command (a) This command is used to ensure that a device is responding to a data recorder or another device. It asks a sensor to acknowledge its presence on the bus. Command format: a<cr><lf> where Device address <cr><lf>...
  • Page 83 Chapter 8, section Wind Sensor. The checksum to be typed in the query depends on the device identifier characters. The correct checksum can be asked from WXT510 by typing any three characters after the $--WIQ,MWV command. VAISALA _______________________________________________________________________ 81...

  • Page 84: Xdr Transducer Measurement Query

    User’s Guide ______________________________________________________________________ Example: Typing the command $--WIQ,MWVxxx<cr><lf> (xxx arbitrary characters) WXT510 responds $WITXT,01,01,08,Use chksum 2F*72<cr><lf> which tells that *2F is the correct checksum for the $--WIQ,MWV command. Example of the MWV Query: $--WIQ,MWV*2F<cr><lf> $WIMWV,282,R,0.1,M,A*37<cr><lf> (Wind angle 282 degrees, Wind speed 0.1 m/s)
  • Page 85 Units of the transducer n measurement, see the following transducer table. c--cn Transducer n id. WXT510's address aXU,A is added as a base number to the Transducer #ID. The address is changeable, see command aXU,A= [0 ... 9/A ... Z/ a ...

  • Page 86: Table 6 Transducer Ids Of The Measurement Parameters

    A+1 for hails. Rain and hail peak intensities are assigned with transducer ids A+2 and A+3, respectively. For example, for a WXT510 with device address 0 the transducer ids of all the measurement parameters are as follows: Table 6...
  • Page 87 Example of the response when all the parameters of each sensor are enabled (NMEA wind formatter set to T): Wind sensor data $WIXDR,A,302,D,0,A,320,D,1,A,330,D,2,S,0.1,M,0,S,0.2,M,1,S,0.2, M,2*57<cr><lf> P, T, and RH data $WIXDR,C,23.3,C,0,C,24.0,C,1,H,50.1,P,0,P,1009.5,H, 0*75<cr><lf> Precipitation data $WIXDR,V,0.02,M,0,Z,30,s,0,R,2.7,M,0,V,0.0,M,1,Z,0,s,1,R,0.0,M,1, R,6.3,M,2,R,0.0,M,3*51<cr><lf> Supervisor data $WIXDR,C,25.5,C,2,U,10.6,N,0,U,10.9,V,1,U,3.360,V,2*71<cr><lf> VAISALA _______________________________________________________________________ 85...
  • Page 88 User’s Guide ______________________________________________________________________ The structure of the wind sensor response message: where Start of the message Device type (WI = weather instrument) Transducer measurement response identifier Transducer id 0 type (wind direction), see the following Transducer table Transducer id 0 data (min wind direction) Transducer id 0 units (degrees, min wind direction) Transducer id for min wind direction Transducer id 1 type (wind direction)
  • Page 89 Transducer id 0 data (Pressure) Transducer id 0 units (hPa, Pressure) Transducer id for Pressure Checksum delimiter Two-character checksum for the response <cr><lf> Response terminator The structure of the precipitation sensor response message: where Start of the message VAISALA _______________________________________________________________________ 87...
  • Page 90 User’s Guide ______________________________________________________________________ Device type (WI = weather instrument) Transducer measurement response identifier Transducer id 0 type (Accumulated rainfall), see the following Transducer table 0.02 Transducer id 0 data (Accumulated rainfall) Transducer id 0 units (mm, Accumulated rainfall) Transducer id for Accumulated rainfall Transducer id 0 type (Rain duration) Transducer id 0 data (Rain duration) Transducer id 0 units (s, Rain duration)
  • Page 91 Transducer id 2 type (voltage) 3.360 Transducer id 2 data (3.5V reference voltage) Transducer id 2 units (V, 3.5V reference voltage) Transducer id for 3.5V reference voltage Checksum delimiter Two-character CRC for the response. <cr><lf> Response terminator VAISALA _______________________________________________________________________ 89...

  • Page 92: Txt Text Transmission

    User’s Guide ______________________________________________________________________ 1. See Chapter 8, section Supervisor Message, Setting Fields for definitions of the Heating voltage field. Table 7 Transducer Table Transducer Type Units Field Comments Temperature C = Celsius F = Fahrenheit Angular displacement D = degrees (wind direction) Wind speed K = km/h, M = m/s, N =...

  • Page 93: Automatic Mode

    The message structure is the same as with the composite data query command aR0 and contains a user configurable set of wind, pressure, temperature, humidity, precipitation and supervisor data. VAISALA _______________________________________________________________________ 91...
  • Page 94 User’s Guide ______________________________________________________________________ Example (the parameters included can be chosen from the full parameter set of the commands aR1, aR2, aR3 and aR5): 0R0,Dx=005D,Sx=2.8M,Ta=23.0C,Ua=30.0P,Pa=1028.2H, Hd=0.00M,Rd=10s,Th=23.6C<cr><lf> For selecting the parameter set in the response message, see Chapter 8, Sensor and Data Message Settings, on page Automatic composite data messaging is a concurrent, not an alternate mode to either the polled or automatic modes.

  • Page 95: Sensor And Data Message Settings

    ASCII, NMEA 0183 and SDI-12. Sensor and data message settings can also be done by using the Vaisala Configuration Tool software.With this software tool you can change the device and sensor settings easily in Windows® environment. See...
  • Page 96 User’s Guide ______________________________________________________________________ where Device address Wind sensor settings command in ASCII and NMEA 0183 Wind sensor settings command in SDI-12 <cr><lf> Command terminator in ASCII and NMEA 0183 Command terminator in SDI-12 The response in ASCII and NMEA 0183: aWU,R=[R],I=[I],A=[A],U=[U],D=[D],N=[N],F=[F]<cr><lf>...

  • Page 97: Setting Fields

    Defines the period over which the wind speed and direction averaging is calculated. See also Appendix D for averaging method. Speed unit: M = m/s, K = km/h, S = mph, N = knots Direction correction: -180 ... 180°, see Wind Direction Correction on page VAISALA _______________________________________________________________________ 95...

  • Page 98: Changing The Settings

    User’s Guide ______________________________________________________________________ NMEA wind formatter: T = XDR (Transducer syntax), W = MWV (Wind speed and angle) Determines whether the wind message in NMEA 0183 (automatic) is sent in XDR or MWV format. Sampling rate: 1, 2, or 4 Hz Defines how often the wind measurement is performed.
  • Page 99 Several parameters can be changed with the same command as long as the command length does not exceed 32 characters, see below. Changing the averaging time to 20 seconds, the wind speed units to knots, and making the direction correction: 0WU,A=20,U=N,D=10<cr><lf> 0WU,A=20,U=N,D=10<cr><lf> VAISALA _______________________________________________________________________ 97...
  • Page 100 User’s Guide ______________________________________________________________________ Changing the wind parameter selection: 0WU,R=0100100001001000<cr><lf> 0WU,R=01001000&00100100<cr><lf> NOTE Character '&' is not allowed in the command. The response after the change: 0R1<cr><lf> 0R1,Dm=268D,Sm=1.8N<cr><lf> Example (SDI-12, device address 0): Changing the measurement interval to 10 seconds: 0XWU,I=10!0<cr><lf> In SDI-12 mode a separate enquiry (0XWU!) must be given to check the data content.

  • Page 101: Pressure, Temperature, And Humidity Sensors

    The response in ASCII and NMEA 0183: aTU,R=[R],I=[I],P=[P],H=[H]<cr><lf> The response in SDI-12: aXTU,R=[R],I=[I],P=[P],H=[H]<cr><lf> where [R][I][P][H] are the setting fields, see the following section. Example (ASCII and NMEA 0183, device address 0): 0TU<cr><lf> 0TU,R=11010000&11010000,I=60,P=H,T=C<cr><lf> Example (SDI-12, device address 0): 0XTU!0XTU,R=11010000&11010000,I=60,P=H,T=C<cr><lf> VAISALA _______________________________________________________________________ 99...

  • Page 102: Setting Fields

    User’s Guide ______________________________________________________________________ Setting Fields Parameter selection: This field consists of 16 bits defining the PTU parameters included in the data messages. The bit value 0 disables and the bit value 1 enables the parameter. The bits 1-8 determine the 1st bit (most left) Pa Air pressure parameters included in the...

  • Page 103: Changing The Settings

    Examples (ASCII and NMEA 0183, device address 0): You need the temperature and humidity data to be available in every 30 seconds Changing the parameter selection: 0TU,R=0101000001010000<cr><lf> 0TU,R=01010000&01010000<cr><lf> NOTE Character '&' is not allowed in the command. VAISALA ______________________________________________________________________ 101...
  • Page 104 User’s Guide ______________________________________________________________________ Changing the update interval: 0TU,I=30<cr><lf> 0TU,I=30<cr><lf> The response after the change: 0R2<cr><lf> 0R2,Ta=23.9C,Ua=26.7P<cr><lf> Example (SDI-12, device address 0): Changing the temperature unit to Fahrenheit: 0XTU,U=F!0<cr><lf> In SDI-12 mode a separate enquiry (0XTU!) must be given to check the data content.

  • Page 105: Precipitation Sensor

    The response in ASCII and NMEA 0183: aRU,R=[R],I=[I],U=[U],S=[S],M=[M],Z=[Z]<cr><lf> The response in SDI-12: aXRU,R=[R],I=[I],U=[U],S=[S],M=[M],Z=[Z]<cr><lf> where [R][I][U][S][M][Z] are the setting fields, see the following section. Example (ASCII and NMEA 0183, device address 0): 0RU<cr><lf> 0RU,R=11111100&10000000,I=60,U=M,S=M,M=R,Z=M<cr><lf> Example (SDI-12, device address 0): 0RU!0RU,R=11111100&10000000,I=60,U=M,S=M,M=R, Z=M<cr><lf> 0RU!0RU,R=11111100&10000000,I=60,U=M,S=M,M=R,Z=M<cr><lf> VAISALA ______________________________________________________________________ 103...

  • Page 106: Setting Fields

    User’s Guide ______________________________________________________________________ Setting Fields Parameter selection: This field consists of 16 bits defining the precipitation parameters included in the data messages. The bit value 0 disables and the bit value 1 enables the parameter. The parameter order is shown in the following table: The bits 1-8 determine the 1st bit (most left) Rc Rain amount...
  • Page 107 Reset (aXZRU) on page A = automatic reset mode: The counts are reset after each precipitation message whether in automatic mode or when polled. Y = immediate reset: The counts are reset immediately after receiving the command. <cr><lf> Response terminator VAISALA ______________________________________________________________________ 105...

  • Page 108: Changing The Settings

    User’s Guide ______________________________________________________________________ NOTE The autosend mode parameter is significant only in ASCII automatic (+CRC) and NMEA 0183 automatic protocols. NOTE Changing the counter reset mode or precipitation/surface hits units also resets precipitation counter and intensity parameters. The accumulation counter resets automatically when the accumulation value exceeds 655.35 mm (or 65.535 inch).
  • Page 109 The response after the change: 0R3<cr><lf> 0R3,Rc=0.00M,Ri=0.0M<cr><lf> Example (SDI-12, device address 0): Changing the counter reset mode (resets the precipitation counters): 0XRU,Z=M!0<cr><lf> In SDI-12 mode a separate enquiry (0XRU!) must be given to check the data content. VAISALA ______________________________________________________________________ 107...

  • Page 110: Supervisor Message

    User’s Guide ______________________________________________________________________ Supervisor Message Checking the Settings With this command you can check the current supervisor settings. Command format in ASCII and NMEA 0183: aSU<cr><lf> Command format in SDI-12: aXSU! where Device address Supervisor settings command in ASCII and NMEA 0183 Supervisor settings command in SDI-12 <cr><lf>...

  • Page 111: Setting Fields

    Heating control enable: Y = enabled, N = disabled Heating enabled: The control between full and half heating power is on as described in Heating (Optional) on page Heating disabled: Heating is off in all conditions. <cr><lf> Response terminator VAISALA ______________________________________________________________________ 109...

  • Page 112: Changing The Settings

    User’s Guide ______________________________________________________________________ Example (ASCII and NMEA 0183, device address 0): 0SU<cr><lf> 0SU,R=11110000&11000000,I=15,S=Y,H=Y<cr><lf> Example (SDI-12, device address 0): 0XSU!0XSU,R=11110000&11000000,I=15,S=Y,H=Y<cr><lf> Changing the Settings You can change the following settings: parameters included in the supervisor data message, update interval, error messaging on/off, and heating control.

  • Page 113: Composite Data Message

    How to format a composite data message with average wind direction, average wind speed, temperature, humidity and pressure data when the original composite data message contains following data: maximum wind direction, maximum wind speed, temperature, humidity, pressure, accumulated rainfall, supply voltage and heating voltage: 0R0<cr><lf> 0R0,Dx=009D,Sx=0.2M,Ta=23.3C,Ua=37.5P,Pa=996.8H, Rc=0.000I,Vs=12.0V,Vh=0.0N<cr><lf> VAISALA ______________________________________________________________________ 111...
  • Page 114 User’s Guide ______________________________________________________________________ Change the maximum wind direction (Dx) and speed (Sx) to average wind direction (Dm) and average wind speed (Sm): 0RU,R=&01001000<cr><lf> 0RU,R=11110000&01001000<cr><lf> Remove the heating voltage (Vh) and temperature (Th) data from the composite data message: 0SU,R=&00000000<cr><lf> 0SU,R=11110000&00000000<cr><lf> Remove the accumulated rainfall (Rc) from the composite data message: 0RU,R=&00000000<cr><lf>...

  • Page 115: Chapter 9 Maintenance

    Cleaning To ensure the accuracy of measurement results, Weather Transmitter WXT510 should be cleaned when it gets contaminated. Leaves and other such particles should be removed from the precipitation sensor and the transmitter should be cleaned carefully with a soft, lint-free cloth moistened with mild detergent.

  • Page 116: Figure 20 Replacing The Ptu Module

    User’s Guide ______________________________________________________________________ Avoid contacting the white filter cap with your hands while inserting the PTU module. Replace the top and tighten the three fixing screws that fasten the top and the bottom. When turning the top back in, make sure that the flat cable does not get stuck or squeezed between the top and the funnel for the flat cable.

  • Page 117: Factory Calibration And Repair Service

    Phone: +81 3 3266 9617, Fax: +81 3 3266 9655 E-mail: aftersales.asia@vaisala.com BEIJING SERVICE CENTER Vaisala China Ltd., Floor 2 EAS Building, No. 21 Xiao Yun Road, Dongsanhuan Beilu, Chaoyang District, Beijing, P.R. CHINA 100027. Phone: +86 10 8526 1199, Fax: +86 10 8526 1155 E-mail: china.service@vaisala.com...
  • Page 118 User’s Guide ______________________________________________________________________ 116 _________________________________________________________________ M210470EN-D...

  • Page 119: Chapter 10 Troubleshooting

    Ensure the proper connection of temperature measurement properly connected. the PTU module. failure. The unit is replaced by a There may be water in the PTU Remove and dry the module. # sign or the data values are module. irrelevant. VAISALA ______________________________________________________________________ 117...

  • Page 120: Table 9 Communication Problems

    A command mistyped in ASCII/ Getting the Data Messages, on NMEA mode while error page messaging/text messages is Enable the error messaging disabled (aSU,S=N). using the Vaisala Configuration Tool or any terminal by setting aSU,S=Y, then try the command again. 118 _________________________________________________________________ M210470EN-D...

  • Page 121: Self-Diagnostics

    Self-Diagnostics Error Messaging/Text Messages WXT510 sends a text message when certain type of errors occur. This function works in all communication modes except in the SDI-12 mode. You may disable error messaging by using the supervisor message aSU, S=N, see Changing the Settings on page 110.

  • Page 122: Table 10 Error Messaging/Text Messages Table

    The precipitation sensor counter reset. Inty reset Precipitation sensor intensity counter reset. See also Chapter 10, Troubleshooting, on page 117. In case of constant error, please contact Vaisala Service Center, see Vaisala Service Centers on page 115. 120 _________________________________________________________________ M210470EN-D...

  • Page 123: Rain And Wind Sensor Heating Control

    (Vs). In case of deviations between the supplied voltage and monitored voltage, check the wiring and the power supply. Technical Support For technical questions, contact the Vaisala technical support: E-mail helpdesk@vaisala.com +358 9 8949 2790...
  • Page 124 User’s Guide ______________________________________________________________________ 122 _________________________________________________________________ M210470EN-D...

  • Page 125: Technical Specifications

    -52 ... +60 °C (-60 ... +140 °F) Accuracy (for sensor element) ±0.3 °C at +20 °C (+68 °F) For accuracy over temperature range, see the following graph Output resolution 0.1 °C (0.1 °F) Units available °C, °F VAISALA ______________________________________________________________________ 123...

  • Page 126: Figure 21 Accuracy Over Temperature Range

    User’s Guide ______________________________________________________________________ °C °C -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7 Figure 21 Accuracy Over Temperature Range 0505-209 Table 13 Relative Humidity Property Description/Value Range 0 ... 100 %RH Accuracy ±3 %RH at 0 ... 90 %RH ±5 %RH at 90 ... 100 %RH Output resolution 0.1 %RH PTU Measuring interval...

  • Page 127: Table 15 Precipitation

    1. Due to the nature of the phenomenon, deviations caused by spatial variations may exist in precipitation readings, especially in short time scale. The accuracy specification does not include possible wind induced error. VAISALA ______________________________________________________________________ 125...

  • Page 128: Inputs And Outputs

    User’s Guide ______________________________________________________________________ Inputs and Outputs Table 16 Inputs and Outputs Property Description/Value Operation voltage 5 ... 30 VDC Average power consumption minimum 0.07 mA @ 12 VDC (SDI-12) typical 3 mA @ 12 VDC (with default measuring intervals) maximum 13 mA @ 30 VDC (constant measurement of all parameters) Heating voltage...

  • Page 129: Materials

    215193 10-meter cable with 8-pin M12 female connector 217020 40-meter cable, open ends 215190 Bushing accessory kit WXT510BOTTOMSP WXT510 Bottom plate (with M12 connector) 212792 Mounting kit WXT510PTUSP WXT510 PTU module 214692 WXT510 Radiation shield (5 pcs) WSP150 Surge Protector...

  • Page 130: Dimensions

    User’s Guide ______________________________________________________________________ Dimensions Figure 22 WXT510 Dimensions in mm [inches] 0505-210 128 _________________________________________________________________ M210470EN-D...

  • Page 131: Figure 23 Mounting Kit Dimensions In Mm [Inches]

    Mounting Kit Dimensions in mm [inches] 0505-211 The following numbers refer to Figure 23 on page 120: Mounting kit with adapter sleeve for ø26.7 mm mast tube Mounting kit without adapter sleeve for ø30 mm mast tube VAISALA ______________________________________________________________________ 129...
  • Page 132 User’s Guide ______________________________________________________________________ 130 _________________________________________________________________ M210470EN-D...

  • Page 133: Appendix Anetworking

    In the data logger end, combine the "GND for data" wires of each WXT510 to the logger "GND for data" wire. Connect the "Data in/ out" wires of each WXT510 to the logger "Data" wire.

  • Page 134: Communication Protocol

    Wiring and Power Management, on page In the data logger end, combine the "Data +" wires of each WXT510 to the logger "Data +" wire. Connect the "Data-" wires of each WXT510 to the logger "Data -" wire. 132 _________________________________________________________________ M210470EN-D...

  • Page 135: Communication Protocol

    No matter which communication protocol, ASCII polled or NMEA query is chosen, the error messaging parameter of the supervisor message must be disactivated with aSU,S=N for each WXT510 on the bus in order to prevent the units responding to the commands not assigned to them.
  • Page 136 0XU,A=0,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=2000 Now, when the XDR-query command $--WIQ,XDR*2D<cr><lf> is sent, WXT510 #1 responds after 25 ms, WXT510 #2 after 1000 ms and WXT510 #3 responds after 2000 ms. The sufficient delays depend on the maximum number of characters in the response messages and the baud rate.
  • Page 137 IDs in the NMEA XDR messages can only be numbers. The addresses given in letters will show in the transducer IDs in the following way: WXT510 address = A => transducer ID = 10, B => 11, a => 36, b => 37 etc.

  • Page 138: Nmea 0183 V3.0 Query With Ascii Query Commands

    WXT510 #1 communication settings: 0XU,A=0,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=25 WXT510 #2 communication settings: 0XU,A=1,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=25 WXT510 #3 communication settings: 0XU,A=2,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=25 The query for WXT510 #1 and the response: 0R<cr><lf> $WIXDR,A,316,D,0,A,326,D,1,A,330,D,2,S,0.1,M,0,S,0.1,M,1,S,0.1, M,2*57<cr><lf> $WIXDR,C,24.0,C,0,C,25.2,C,1,H,47.4,P,0,P,1010.1,H, 0*54<cr><lf> $WIXDR,V,0.000,I,0,Z,10,s,0,R,0.01,I,0,V,0.0,M,1,Z,0,s,1,R,0.0,M, 1*51<cr><lf>...
  • Page 139 Appendix A ______________________________________________________________ Networking $WIXDR,C,23.5,C,1,C,24.3,C,2,H,49.3,P,1,P,1010.1,H, 1*59<cr><lf> $WIXDR,V,0.000,I,1,Z,0,s,1,R,0.00,I,1,V,0.0,M,2,Z,0,s,2,R,0.0,M, 2*67<cr><lf> $WIXDR,C,25.8,C,3,U,10.6,N,1,U,10.9,V,1,U,3.362,V,2*78<cr><lf> The query for WXT510 #3 and the response: 2R<cr><lf> $WIXDR,A,341,D,2,A,347,D,3,A,357,D,4,S,0.1,M,2,S,0.2,M,3,S,0.2, M,4*53<cr><lf> $WIXDR,C,23.5,C,2,C,24.3,C,3,H,49.3,P,2,P,1010.1,H, 2*5F<cr><lf> $WIXDR,V,0.000,I,2,Z,0,s,2,R,0.00,I,2,V,0.0,M,3,Z,0,s,3,R,0.0,M, 3*61<cr><lf> $WIXDR,C,25.8,C,4,U,10.6,N,2,U,10.9,V,2,U,3.360,V,3*7C<cr><lf> If needed, for making the transducers IDs distinguishable, device addresses 0, 4, 8 can be used as described in the previous section.
  • Page 140 User’s Guide ______________________________________________________________________ 138 _________________________________________________________________ M210470EN-D...

  • Page 141: Sdi-12 Protocol

    SDI-12 data recorders and sensors communicate by an exchange of ASCII characters on the data line. The data recorder sends a break to wake up the sensors on the data line. A break is continuous spacing on VAISALA ______________________________________________________________________ 139...

  • Page 142: Sdi-12 Timing

    User’s Guide ______________________________________________________________________ the data line for at least 12 milliseconds. The data recorder then sends a command. The sensor, in turn, returns the appropriate response. Each command is for a specific sensor. The first character of each command is a unique sensor address that specifies with which sensor the recorder wants to communicate.

  • Page 143: Figure 24 Timing Diagram

    100 milliseconds (tolerance: +0.40 milliseconds). When a recorder addresses a different sensor, or if the data line has been in the marking state for more than 87 milliseconds, the next command must be preceded by a break. VAISALA ______________________________________________________________________ 141...
  • Page 144 User’s Guide ______________________________________________________________________ NOTE The low-power standby mode, in addition to being a low-power consumption state, is a protocol state and a break is required to leave that state. 142 _________________________________________________________________ M210470EN-D...

  • Page 145: Crc-16 Computation

    =1 to 8 if the least significant bit of the CRC is one right shift the CRC one bit set CRC equal to the exclusive OR of 0xA001 and itself else right shift the CRC one bit VAISALA ______________________________________________________________________ 143...

  • Page 146: Encoding The Crc As Ascii Characters

    User’s Guide ______________________________________________________________________ Encoding the CRC as ASCII Characters The 16 bit CRC is encoded to three ASCII characters by using the following algorithm: 1st character = 0x40 OR (CRC shifted right 12 bits) 2nd character = 0x40 OR ((CRC shifted right 6 bits) AND 0x3F) 3rd character = 0x40 OR (CRC AND 0x3F) The three ASCII characters are placed between the data and <cr><lf>.

  • Page 147: Wind Measurement Averaging Method

    (I) and averaging time (A). Scalar averaging is used for both wind speed and direction. For direction, zero degree crossing, when present, is taken correctly into account in averaging. VAISALA ______________________________________________________________________ 145...

  • Page 148: Figure 25 Wind Measurement Averaging Method

    User’s Guide ______________________________________________________________________ Case 1 I > A, all other communication protocols than SDI-12 (aXU,M=S). In this example I=5 sec and A=3 sec. time 1 sec Case 2 I < A, all other communication protocols than SDI-12 (aXU,M=S). In this example I=2 sec and A=5 sec. time 1 sec Case 3...
  • Page 149 Wind measurement sampling rate (4, 2, or 1 Hz) does not have any effect on the averaging scheme. It determines from how many samples the one second values seen in the figures are calculated. VAISALA ______________________________________________________________________ 147...
  • Page 150 User’s Guide ______________________________________________________________________ 148 _________________________________________________________________ M210470EN-D...
  • Page 152 www.vaisala.com...

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