Vaisala WXT 520 Weather Transmitter User’s Guide
Below you will find brief information for Weather Transmitter WXT520. The WXT520 is a small and lightweight transmitter that offers six weather parameters in one compact package. It measures wind speed and direction, precipitation, atmospheric pressure, temperature and relative humidity. This device is IP65 rated, powers up with 5 ... 32 VDC and output serial data with a selectable communication protocol: SDI-12, ASCII automatic & polled and NMEA 0183 with query option.
PDF
Download
Document
Advertisement
Advertisement
USER'S GUIDE Vaisala Weather Transmitter WXT520 M210906EN-A PUBLISHED BY Vaisala Oyj Phone (int.): +358 9 8949 1 P.O. Box 26 Fax: +358 9 8949 2227 FIN-00421 Helsinki Finland Visit our Internet pages at http://www.vaisala.com/ © Vaisala 2008 No part of this manual may be reproduced in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be communicated to a third party without prior written permission of the copyright holder. 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 applicable supply contract or Conditions of Sale. ________________________________________________________________________________ Table of Contents CHAPTER 1 GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Contents of This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . 11 General Safety Considerations . . . . . . . . . . . . . . . . . . . . . 12 Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 ESD Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 License Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Regulatory Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 CHAPTER 2 PRODUCT OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Weather Transmitter WXT520 . . . . . . . . . . . . . . . . . . . . . . . 17 Heating Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Optional Software for Easy Settings . . . . . . . . . . . . . . . . . 18 WXT520 Transmitter Components . . . . . . . . . . . . . . . . . . . 19 CHAPTER 3 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Wind Measurement Principle . . . . . . . . . . . . . . . . . . . . . . . . 25 Precipitation Measurement Principle . . . . . . . . . . . . . . . . . 27 PTU Measurement Principle . . . . . . . . . . . . . . . . . . . . . . . . . 28 Heating (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 CHAPTER 4 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Unpacking the Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Selecting the Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Installation Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Mounting to Vertical Pole Mast . . . . . . . . . . . . . . . . . . 34 Mounting with Mounting Kit (Optional) . . . . . . . . . . . . . 35 Mounting To Horizontal Cross Arm . . . . . . . . . . . . . . . 37 Grounding the WXT520 . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Grounding using the Bushing and Grounding Kit. . . . . 38 Marine Grounding Jumper . . . . . . . . . . . . . . . . . . . . . . 39 VAISALA ________________________________________________________________________ 1 ________________________________________________________________________________ Aligning WXT520 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Compass Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Wind Direction Offset . . . . . . . . . . . . . . . . . . . . . . . . . . 42 CHAPTER 5 WIRING AND POWER MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . .43 Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43 Wiring Using the 8-pin M12 Connector . . . . . . . . . . . . . . . .46 External Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 Wiring Using the Screw Terminals . . . . . . . . . . . . . . . . . . .48 Data Communication Interfaces . . . . . . . . . . . . . . . . . . . . .50 Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 CHAPTER 6 CONNECTION OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 Communication Protocols . . . . . . . . . . . . . . . . . . . . . . . . . .55 Connection cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Installing the Driver for the USB Cable . . . . . . . . . . . . . . .57 Service Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . .58 Connection Through M12 Bottom Connector or Screw Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 Communication Setting Commands . . . . . . . . . . . . . . . . . .59 Checking the Current Communication Settings (aXU) . . . .60 Setting Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Changing the Communication Settings (aXU) . . . . . . . . . .62 CHAPTER 7 GETTING THE DATA MESSAGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 General Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 Reset (aXZ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 Precipitation Counter Reset (aXZRU) . . . . . . . . . . . . . . . .67 Precipitation Intensity Reset (aXZRI) . . . . . . . . . . . . . . . . .68 Measurement Reset (aXZM) . . . . . . . . . . . . . . . . . . . . . . .69 ASCII Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 Abbreviations and Units . . . . . . . . . . . . . . . . . . . . . . . . . . .70 Device Address (?) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Acknowledge Active Command (a) . . . . . . . . . . . . . . . . . .71 Wind Data Message (aR1) . . . . . . . . . . . . . . . . . . . . . . . . .72 Pressure, Temperature and Humidity Data Message (aR2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Precipitation Data Message (aR3) . . . . . . . . . . . . . . . . . . .74 Supervisor Data Message (aR5) . . . . . . . . . . . . . . . . . . . .75 Combined Data Message (aR) . . . . . . . . . . . . . . . . . . . . . .76 Composite Data Message Query (aR0) . . . . . . . . . . . . . . .76 Polling with CRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 Automatic Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79 Automatic Composite Data Message (aR0) . . . . . . . . . . . .79 2 _______________________________________________________________________________ ________________________________________________________________________________ SDI-12 Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Address Query Command (?) . . . . . . . . . . . . . . . . . . . . . . 81 Acknowledge Active Command (a) . . . . . . . . . . . . . . . . . . 81 Change Address Command (aAb) . . . . . . . . . . . . . . . . . . . 82 Send Identification Command (aI) . . . . . . . . . . . . . . . . . . . 83 Start Measurement Command (aM) . . . . . . . . . . . . . . . . . 83 Start Measurement Command with CRC (aMC) . . . . . . . . 85 Start Concurrent Measurement (aC) . . . . . . . . . . . . . . . . . 85 Start Concurrent Measurement with CRC (aCC) . . . . . . . . 86 Send Data Command (aD) . . . . . . . . . . . . . . . . . . . . . . . . 87 Examples of aM, aC and aD Commands . . . . . . . . . . . . . . 88 Continuous Measurement (aR) . . . . . . . . . . . . . . . . . . . . . 90 Continuous Measurement with CRC (aRC) . . . . . . . . . . . . 92 Start Verification Command (aV) . . . . . . . . . . . . . . . . . . . . 92 NMEA 0183 V3.0 Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Device Address (?) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Acknowledge Active Command (a) . . . . . . . . . . . . . . . . . . 93 MWV Wind Speed and Direction Query . . . . . . . . . . . . . . . 94 XDR Transducer Measurement Query . . . . . . . . . . . . . . . 95 TXT Text Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Automatic Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Automatic Composite Data Message (aR0) . . . . . . . . . . . 105 CHAPTER 8 SENSOR AND DATA MESSAGE SETTINGS . . . . . . . . . . . . . . . . . . . . . 107 Wind Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Checking the Settings (aWU) . . . . . . . . . . . . . . . . . . . . . . 107 Setting Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Changing the Settings (aWU) . . . . . . . . . . . . . . . . . . . . . 111 Pressure, Temperature, and Humidity Sensors . . . . . . . . 113 Checking the Settings (aTU) . . . . . . . . . . . . . . . . . . . . . . 113 Setting Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Changing the Settings (aTU) . . . . . . . . . . . . . . . . . . . . . . 115 Precipitation Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Checking the Settings (aRU) . . . . . . . . . . . . . . . . . . . . . . 116 Setting Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Changing the Settings (aRU) . . . . . . . . . . . . . . . . . . . . . . 121 Supervisor Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Checking the Settings (aSU) . . . . . . . . . . . . . . . . . . . . . . 122 Setting Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Changing the Settings (aSU) . . . . . . . . . . . . . . . . . . . . . . 124 Composite Data Message (aR0) . . . . . . . . . . . . . . . . . . . . . 125 CHAPTER 9 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Replacing the PTU Module . . . . . . . . . . . . . . . . . . . . . . . . . 128 Factory Calibration and Repair Service . . . . . . . . . . . . . . 129 Vaisala Service Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 VAISALA ________________________________________________________________________ 3 ________________________________________________________________________________ CHAPTER 10 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131 Self-Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133 Error Messaging/Text Messages . . . . . . . . . . . . . . . . . . .133 Rain and Wind Sensor Heating Control . . . . . . . . . . . . . .135 Operating Voltage Control . . . . . . . . . . . . . . . . . . . . . . . .135 Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135 CHAPTER 11 TECHNICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137 Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137 Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142 Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . .143 Dimensions (mm/inch) . . . . . . . . . . . . . . . . . . . . . . . . . . . .144 APPENDIX A NETWORKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 Connecting Several WXT520s on the Same Bus . . . . . . .147 SDI-12 Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 Communication Protocol . . . . . . . . . . . . . . . . . . . . . . . . .148 RS-485 Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . .148 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .148 Communication Protocol . . . . . . . . . . . . . . . . . . . . . . . . .149 ASCII, Polled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149 NMEA 0183 v3.0, Query . . . . . . . . . . . . . . . . . . . . . . . . .150 NMEA 0183 v3.0 Query with ASCII Query Commands . .152 APPENDIX B SDI-12 PROTOCOL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155 SDI-12 Electrical Interface . . . . . . . . . . . . . . . . . . . . . . . . .155 SDI-12 Communications Protocol . . . . . . . . . . . . . . . . . .156 SDI-12 Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 APPENDIX C CRC-16 COMPUTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159 Encoding the CRC as ASCII Characters . . . . . . . . . . . . . .160 NMEA 0183 v3.0 Checksum Computation . . . . . . . . . . . .160 APPENDIX D WIND MEASUREMENT AVERAGING METHOD . . . . . . . . . . . . . . . . . . .161 APPENDIX E 4 _______________________________________________________________________________ ________________________________________________________________________________ FACTORY CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 General Unit Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Wind Configuration Settings . . . . . . . . . . . . . . . . . . . . . . . 164 PTU Configuration Settings . . . . . . . . . . . . . . . . . . . . . . . . 165 Rain Configuration Settings . . . . . . . . . . . . . . . . . . . . . . . . 165 Supervisor Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 VAISALA ________________________________________________________________________ 5 ________________________________________________________________________________ 6 _______________________________________________________________________________ ________________________________________________________________________________ List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Figure 32 Vaisala Weather Transmitter WXT520. . . . . . . . . . . . . . . . . . . 17 Main Components of Weather Transmitter WXT520 . . . . . . . . 19 Cut Away View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Bottom of Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Mounting Kit (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 USB Cables (optional). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Bird Spike Kit (optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Surge Protector (optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Heating Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Recommended Mast Location in an Open Area . . . . . . . . . . . 32 Recommended Mast Length on Top of a Building . . . . . . . . . . 33 Location of Fixing Screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Mounting WXT520 to Pole Mast Using Optional Mounting Kit. 36 Mounting WXT520 to Cross Arm (L-Profile). . . . . . . . . . . . . . . 37 Mounting Bolt Location in Cross Arm. . . . . . . . . . . . . . . . . . . . 38 Grounding Using the Bushing and Grounding Kit . . . . . . . . . . 39 Grounding Jumper Location. . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Sketch of Magnetic Declination . . . . . . . . . . . . . . . . . . . . . . . . 41 Wind Direction Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Average Operational Current Consumption (with 4Hz Wind Sensor Sampling) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Heating Current and Power vs Vh . . . . . . . . . . . . . . . . . . . . . . 45 Pins of 8-pin M12 Connector . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Screw Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Data Communication Interfaces. . . . . . . . . . . . . . . . . . . . . . . . 50 Replacing the PTU Module . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Accuracy Over Temperature Range . . . . . . . . . . . . . . . . . . . 138 WXT520 Dimensions, Side View . . . . . . . . . . . . . . . . . . . . . . 144 WXT520 Dimensions, Top and Bottom View . . . . . . . . . . . . . 145 Mounting Kit Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Wind Measurement Averaging Method . . . . . . . . . . . . . . . . . 162 VAISALA ________________________________________________________________________ 7 ________________________________________________________________________________ 8 _______________________________________________________________________________ ________________________________________________________________________________ List of Tables Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Table 10 Table 11 Table 12 Table 13 Table 14 Table 15 Table 16 Table 17 Table 18 Table 19 Table 20 Table 21 Table 22 Table 23 Table 24 Table 25 Table 26 Table 27 Pin-outs for WXT520 Serial Interfaces and Power Supplies . . . . 46 Screw Terminal Pin-outs for WXT520 Serial Interfaces and Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Available Serial Communication Protocols . . . . . . . . . . . . . . . . . 55 Connection Cable Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Default Serial Communication Settings for M12/Screw Terminal Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Abbreviations and Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Transducer IDs of the Measurement Parameters . . . . . . . . . . . . 98 Transducer Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Data Validation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Communication Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 Error Messaging/Text Messages Table . . . . . . . . . . . . . . . . . . . . 134 Barometric Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Air Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Wind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Relative Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Inputs and Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Electromagnetic Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 General Unit Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Wind Configuration Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 PTU Configuration Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Rain Configuration Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 General Unit Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 VAISALA ________________________________________________________________________ 9 ________________________________________________________________________________ 10 ______________________________________________________________________________ Chapter 1 ________________________________________________________ General Information CHAPTER 1 GENERAL INFORMATION This chapter provides general notes for the product. About This Manual This manual provides information for installing, operating, and maintaining Vaisala Weather Transmitter WXT520. Contents of This Manual This manual consists of the following chapters: - Chapter 1, General Information: This chapter provides general notes for the product. - Chapter 2, Product Overview: This chapter introduces the unique features and advantages of the Vaisala Weather Transmitter WXT520. - Chapter 3, Functional Description: This chapter describes the measurement principles and heating function of Weather Transmitter WXT520. - Chapter 4, Installation: This chapter provides you with information that is intended to help you install Weather Transmitter WXT520. VAISALA _______________________________________________________________________ 11 User’s Guide ______________________________________________________________________ - Chapter 5, Wiring and Power Management: This chapter provides you with instructions on how to connect the power supply and the serial interfaces, and how to manage and estimate the power consumption. - Chapter 6, Connection Options: This chapter contains instructions for configuring the communication with the transmitter. - Chapter 7, Getting the Data Messages: This chapter presents the general and data message commands. - Chapter 8, Sensor and Data Message Settings: This chapter presents the sensor configuration and data message formatting commands for all communications protocols: ASCII, NMEA 0183 and SDI-12. - Chapter 9, Maintenance: This chapter contains instructions for the basic maintenance of Weather Transmitter WXT520 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. - Chapter 11, Technical Specifications: This chapter provides the technical data of Weather Transmitter WXT520. General Safety Considerations Throughout the manual, important safety considerations are highlighted as follows: WARNING Warning alerts you to a serious hazard. If you do not read and follow instructions very carefully at this point, there is a risk of injury or even death. CAUTION Caution warns you of a potential hazard. If you do not read and follow instructions carefully at this point, the product could be damaged or important data could be lost. NOTE Note highlights important information on using the product. 12 ___________________________________________________________________M210906EN-A Chapter 1 ________________________________________________________ General Information Feedback Vaisala Customer Documentation Team welcomes your comments and suggestions on the quality and usefulness of this publication. If you find errors or have other suggestions for improvement, please indicate the chapter, section, and page number. You can send comments to us by e-mail: [email protected]. 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. To make sure you are not delivering high static voltages yourself: - Handle ESD sensitive components on a properly grounded and protected ESD workbench. When this is not possible, ground yourself with a wrist strap and a resistive connection cord to the equipment chassis before touching the boards. When neither of the above is possible, at least touch a conductive part of the equipment chassis with your other hand before touching the boards. - Always hold the boards by the edges and avoid touching the component contacts. Recycling Recycle all applicable material. Dispose of batteries and the unit according to statutory regulations. Do not dispose of with regular household refuse. VAISALA _______________________________________________________________________ 13 User’s Guide ______________________________________________________________________ Trademarks WINDCAP®, RAINCAP®, HUMICAP®, BAROCAP® and THERMOCAP® are registered trademarks of Vaisala. Microsoft®, Windows®, Windows 2000®, Windows XP®, Windows Server 2003®, and Windows Vista® are registered trademarks of 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. Regulatory Compliance The electromagnetic compatibility of the WXT520 has been tested according to the following product family standard: IEC 61326-1 Electrical equipment for measurement, control and laboratory use - EMC requirements - for use in industrial locations. Additionally, the EMC specification of the WXT520 has been enhanced for marine use according to the following sections of the IEC 60945 Maritime Navigation and Radiocommunication Equipment and Systems - General requirements - Methods of testing and required test results: - IEC 60945 / 61000-4-4 (EFT burst) - IEC 60945 / 61000-4-2 (Marine ESD) A summary of the test results is presented in Table 19 on page 141. The WXT520 is in conformance with the provisions of the RoHS directive of the European Union: Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (2002/95/EC) 14 ___________________________________________________________________M210906EN-A Chapter 1 ________________________________________________________ General Information Warranty Vaisala hereby represents and warrants all Products manufactured by Vaisala and sold hereunder to be free from defects in workmanship or material during a period of twelve (12) months from the date of delivery save for products for which a special warranty is given. If any Product proves however to be defective in workmanship or material within the period herein provided Vaisala undertakes to the exclusion of any other remedy to repair or at its own option replace the defective Product or part thereof free of charge and otherwise on the same conditions as for the original Product or part without extension to original warranty time. Defective parts replaced in accordance with this clause shall be placed at the disposal of Vaisala. Vaisala also warrants the quality of all repair and service works performed by its employees to products sold by it. In case the repair or service works should appear inadequate or faulty and should this cause malfunction or nonfunction of the product to which the service was performed Vaisala shall at its free option either repair or have repaired or replace the product in question. The working hours used by employees of Vaisala for such repair or replacement shall be free of charge to the client. This service warranty shall be valid for a period of six (6) months from the date the service measures were completed. This warranty is however subject to following conditions: a) A substantiated written claim as to any alleged defects shall have been received by Vaisala within thirty (30) days after the defect or fault became known or occurred, and b) The allegedly defective Product or part shall, should Vaisala so require, be sent to the works of Vaisala or to such other place as Vaisala may indicate in writing, freight and insurance prepaid and properly packed and labelled, unless Vaisala agrees to inspect and repair the Product or replace it on site. This warranty does not however apply when the defect has been caused through a) normal wear and tear or accident; b) misuse or other unsuitable or unauthorized use of the Product or negligence or error in storing, maintaining or in handling the Product or any equipment thereof; c) wrong installation or assembly or failure to service the Product or otherwise follow Vaisala's service instructions including any repairs or installation or assembly or service made by unauthorized personnel not approved by Vaisala or replacements with parts not manufactured or supplied by Vaisala; d) modifications or changes of the Product as well as any adding to it without Vaisala's prior authorization; e) other factors depending on the Customer or a third party. Notwithstanding the aforesaid Vaisala's liability under this clause shall not apply to any defects arising out of materials, designs or instructions provided by the Customer. This warranty is expressly in lieu of and excludes all other conditions, warranties and liabilities, express or implied, whether under law, statute or otherwise, including without limitation any implied warranties of merchantability or fitness for a particular purpose and all other obligations and liabilities of Vaisala or its representatives with respect to any defect or deficiency applicable to or resulting directly or indirectly from the Products supplied hereunder, which obligations and liabilities are hereby expressly cancelled and waived. Vaisala's liability shall under no circumstances exceed the invoice price of any Product for which a warranty claim is made, nor shall Vaisala in any circumstances be liable for lost profits or other consequential loss whether direct or indirect or for special damages. VAISALA _______________________________________________________________________ 15 User’s Guide ______________________________________________________________________ 16 ___________________________________________________________________M210906EN-A Chapter 2 __________________________________________________________ Product Overview CHAPTER 2 PRODUCT OVERVIEW This chapter introduces the unique features and advantages of the Vaisala Weather Transmitter WXT520. Weather Transmitter WXT520 0504-066 Figure 1 Vaisala Weather Transmitter WXT520 VAISALA _______________________________________________________________________ 17 User’s Guide ______________________________________________________________________ Weather Transmitter WXT520 is a small and lightweight transmitter that offers six weather parameters in one compact package. WXT520 measures wind speed and direction, precipitation, atmospheric pressure, temperature and relative humidity. The transmitter housing is IP65/IP66 rated. WXT520 powers up with 5 ... 32 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. The transmitter is equipped with a 8-pin M12 connector for installation, and a 4-pin M8 connector for service use. The following options are available: - Heating function for the precipitation and wind sensors - Service Pack 2: Windows® based Vaisala Configuration Tool software with USB service cable (1.4m) - USB RS-232/RS-485 cable (1.4m) - Mounting kit - Bird spike kit - Surge protector - Shielded cables (2m, 10m, 40m) - Bushing and grounding kit Heating Function To improve the accuracy of measurements an optional heating for the wind and precipitation sensors is available. More about heating in section Heating (Optional) on page 29. The heating function option must be chosen when placing the order. Optional Software for Easy Settings Windows® based Vaisala Configuration Tool is a user friendly parameter setting software for WXT520. With this software tool you can change the device and sensor settings easily in Windows® environment. See list of options and accessories in Table 22 on page 143. 18 ___________________________________________________________________M210906EN-A Chapter 2 __________________________________________________________ Product Overview WXT520 Transmitter Components 0804-021 Figure 2 Main Components of Weather Transmitter WXT520 The following numbers refer to Figure 2 on page 19: 1 = Top of the transmitter 2 = Radiation shield 3 = Bottom of the transmitter 4 = Screw cover VAISALA _______________________________________________________________________ 19 User’s Guide ______________________________________________________________________ 0803-028 Figure 3 Cut Away View The following numbers refer to Figure 3 on page 20: 1 = Wind transducers (3 pcs) 2 = Precipitation sensor 3 = Pressure sensor inside the PTU module 4 = Humidity and temperature sensors inside the PTU module 20 ___________________________________________________________________M210906EN-A Chapter 2 __________________________________________________________ Product Overview 0803-029 Figure 4 Bottom of Transmitter The following numbers refer to Figure 4 on page 21: 1 = Alignment direction sign 2 = 4-pin M8 connector for Service Port 3 = Water tight cable gland (optional, included in the Bushing and Grounding Kit) 4 = Opening for cable gland (if unused, cover with a hexagonal plug) 5 = 8-pin M12 connector for power/datacom cable (optional) VAISALA _______________________________________________________________________ 21 User’s Guide ______________________________________________________________________ 0505-193 Figure 5 Mounting Kit (Optional) The optional mounting kit can be used to ease the mounting of the WXT520 on a pole mast. When using the optional mounting kit, alignment is needed only when mounting for the first time. Using the mounting kit also improves the IP classification of the WXT520 to IP66. Without the mounting kit, the WXT520 is IP65. 0804-022 Figure 6 USB Cables (optional) The following numbers refer to Figure 6 on page 22: 1 = USB RS-232/RS-485 cable with 8-pin M12 threaded connector (1.4 m) 2 = USB service cable with 4-pin M8 snap-on connector (1.4 m) The service cable, while connected between the service port and PC, forces the service port to RS-232 / 19200, 8, N, 1. 22 ___________________________________________________________________M210906EN-A Chapter 2 __________________________________________________________ Product Overview 0804-007 Figure 7 Bird Spike Kit (optional) The optional Bird Spike Kit for WXT and WMT transmitters is designed to reduce the interference that birds cause to the wind and rain measurement. The kit consists of a metallic band with spikes pointing upward. The kit is installed on top of the transmitter, and attached with a screw. The shape and location of the spikes has been designed so that the interference with wind and rain measurement is minimal. The spikes are designed not to hurt the birds; they are simply a barrier to make it more difficult for birds to land on top of the transmitter. Note that the bird spike kit does not provide complete protection against birds, but it does render the transmitter unsuitable for roosting and nest building. Note that when the kit is in place, more snow can accumulate on the transmitter, and the snow may melt slower. VAISALA _______________________________________________________________________ 23 User’s Guide ______________________________________________________________________ 0806-001 Figure 8 Surge Protector (optional) The following surge protectors are available from Vaisala: - Vaisala Surge Protector WSP150 is a compact transient overvoltage suppressor designed for outdoor use. It can be used with all Vaisala wind and weather instruments. The WSP150 should be installed close to the protected instrument (max 3 m). - Vaisala Surge Protector WSP152 is designed to be used with Vaisala WXT transmitters and WMT sensors, to protect the host PC against surges entering through the USB port. The WSP152 should be installed close to the PC, no further than the USB cable can reach (1.4 m). Vaisala recommends using surge protectors when weather instruments are installed on top of high buildings or masts and in open grounds, that is, anywhere with an elevated risk of lightning strike. Also use the surge protectors if your cable length exceeds 30 m or you have unshielded, open-wire lines. 24 ___________________________________________________________________M210906EN-A Chapter 3 ______________________________________________________ Functional Description CHAPTER 3 FUNCTIONAL DESCRIPTION This chapter describes the measurement principles and heating function of Weather Transmitter WXT520. Wind Measurement Principle WXT520 uses Vaisala WINDCAP® sensor technology in wind measurement. The wind sensor has an array of three equally spaced ultrasonic transducers on a horizontal plane. Wind speed and wind directions are determined by measuring the time it takes the ultrasound to travel from each transducer to the other two. The wind sensor measures the transit time (in both directions) along the three paths established by the array of transducers. This transit time depends on the wind speed along the ultrasonic path. For zero wind speed, both the forward and reverse transit times are the same. With wind along the sound path, the up-wind direction transit time increases and the down-wind transit time decreases. VAISALA _______________________________________________________________________ 25 User’s Guide ______________________________________________________________________ The wind speed is calculated from the measured transit times using the following formula: V w = 0.5 u L u 1 e t f – 1 e t r 0505-216 where Vw = Wind speed L = Distance between the two transducers tf = Transit time in forward direction tr = Transit time in reverse direction Measuring the six transit times allows Vw to be computed for each of the three ultrasonic paths. The computed wind speeds are independent of altitude, temperature and humidity, which are cancelled out when the transit times are measured in both directions, although the individual transit times depend on these parameters. Using Vw values of two array paths is enough to compute wind speed and wind direction. A signal processing technique is used so that wind speed and wind direction are calculated from the two array paths of best quality. 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 WXT520 indicates the direction that the wind comes from. North is represented as 0°, east as 90°, south as 180°, and west as 270°. The wind direction is not calculated when the wind speed drops below 0.05 m/s. In this case, the last calculated direction output remains until the wind speed increases again to the level of 0.05 m/s. The average values of wind speed and direction are calculated as a scalar average of all samples over the selected averaging time (1 ... 3600 s) with a selectable updating interval. The sample count depends on the selected sampling rate: 4 Hz (default), 2 Hz or 1 Hz. The minimum and maximum values of wind speed and direction represent the corresponding extremes during the selected averaging time. See also Appendix D, Wind Measurement Averaging Method, on page 161. 26 ___________________________________________________________________M210906EN-A Chapter 3 ______________________________________________________ Functional Description Depending on user selection the wind speed extreme values can be computed in two alternative ways; either with the traditional minimum/ maximum calculation or with the 3-second gust & lull calculation recommended by the WMO (World Meteorological Organization). In the latter case the highest and lowest 3-second average values (updated once a second) replace the maximum and minimum values in reporting of wind speed, while the wind direction variance is returned in the traditional way. The WXT520 constantly monitors the wind measurement signal quality. If poor quality is detected, the wind values are marked as invalid. If over half of the measurement values can be considered as invalid, the last valid wind values are returned as missing data. However, in the SDI-12 protocol the invalid values will be marked as zeroes. Precipitation Measurement Principle WXT520 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. Hence, the signal of each drop can be converted directly to accumulated rainfall. Advanced noise filtering technique is used to filter out signals originating from other sources than raindrops. The measured parameters are accumulated rainfall, rain current and peak intensity, and the duration of a rain event. Detection of each individual drop enables computing of rain amount and intensity with high resolution. Precipitation current intensity internally updated every 10 seconds represents the intensity during the one minute period before requesting/automatic precipitation message sending (for fast reacting to a rain event, during the first minute of the rain event the intensity is calculated over the period rain has lasted in 10-second steps instead of fixed one minute). Precipitation peak intensity represents the maximum of the calculated current intensity values since last precipitation intensity reset. VAISALA _______________________________________________________________________ 27 User’s Guide ______________________________________________________________________ The sensor is also capable of distinguishing hails from raindrops. The measured hail parameters are cumulative amount of hails, current and peak hail intensity and the duration of a hail shower. The precipitation sensor operates in the following four modes: - Precipitation Start/End mode: Transmitter sends automatically a precipitation message 10 seconds after the recognition of the first drop. The messages are sent continuously as the precipitation proceeds and stopped when the precipitation ends. - Tipping bucket mode: This mode emulates tipping bucket type precipitation sensors. Transmitter sends automatically a precipitation message when the counter detects one unit increment (0.1 mm/0.01 in). - 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 116. PTU Measurement Principle The PTU module contains separate sensors for pressure, temperature, and humidity measurement. The measurement principle of the pressure, temperature, and humidity sensors is based on an advanced RC oscillator and two reference capacitors against which the capacitance of the sensors is continuously measured. The microprocessor of the transmitter performs compensation for the temperature dependency of the pressure and humidity sensors. 28 ___________________________________________________________________M210906EN-A Chapter 3 ______________________________________________________ Functional Description The PTU module includes - capacitive silicon BAROCAP® sensor for pressure measurement, - capacitive ceramic THERMOCAP® sensor for air temperature measurement, and - capacitive thin film polymer HUMICAP®180 sensor for humidity measurement. Heating (Optional) Heating elements located below the precipitation sensor and inside the wind transducers keep the precipitation and wind sensors clean from snow and ice. A heating temperature sensor (Th) underneath the precipitation sensor controls the heating. Note that Th is measured inside the equipment, where temperature is much higher than the ambient temperature (Ta). Three fixed temperature limits, namely +4 °C, 0 °C, and -4 °C (+39 °F, +32 °F, +25 °F) control the heating as follows: 0806-010 Figure 9 Heating Control VAISALA _______________________________________________________________________ 29 User’s Guide ______________________________________________________________________ The following example shows how heating behaves as Ta starts to fall: - When Ta falls below +4 °C, heating is enabled. - Heating keeps Th > +4 °C until Ta < -1 °C. - Heating keeps Th > 0 °C until Ta < -15 °C. When the heating function is disabled the heating is off in all conditions, see Supervisor Message on page 122. NOTE Snow accumulation may cause a temporary wind measurement problem even when the heating is enabled. 30 ___________________________________________________________________M210906EN-A Chapter 4 _______________________________________________________________ Installation CHAPTER 4 INSTALLATION This chapter provides you with information that is intended to help you install Weather Transmitter WXT520. Unpacking the Transmitter Weather Transmitter WXT520 comes in a custom shipping container. Be careful when removing the device from the container. CAUTION Beware of damaging any of the wind transducers located at the top of the three antennas. Dropping the device can break or damage the transducers. If the antenna bends or twists, re-aligning can be difficult or impossible. VAISALA _______________________________________________________________________ 31 User’s Guide ______________________________________________________________________ Selecting the Location Finding a suitable site for Weather Transmitter WXT520 is important for getting representative ambient measurements. The site should represent the general area of interest. Weather Transmitter WXT520 should be installed in a location that is free from turbulence caused by nearby objects, such as trees and buildings. In general, any object of height (h) will not remarkably disturb wind measurement at a minimum distance of 10 h. There should be at least 150 m open area in all directions from the mast. Refer to Figure 10 on page 32. 0712-008 Figure 10 Recommended Mast Location in an Open Area 32 ___________________________________________________________________M210906EN-A Chapter 4 _______________________________________________________________ Installation 0712-009 Figure 11 Recommended Mast Length on Top of a Building The recommended minimum length (marked with the letter h in Figure 11 on page 33) for the mast that is installed on top of a building is 1.5 times the height of the building (H). When the diagonal (W) is less than the height (H), the minimum length of the mast is 1.5 W. CAUTION Installations on top of high buildings or masts and in sites on open grounds are vulnerable to lightning strikes. A nearby lightning strike may induce a high-voltage surge not tolerable by the internal surge suppressors of the instrument. Additional protection is needed in regions with frequent, severe thunderstorms, especially when long line cables (> 30m) are used. Vaisala recommends using a surge protectors such as the WSP150 and WSP152 in all sites where there is an elevated risk of lightning strike. WARNING To protect personnel (and the device), a lightning rod should be installed with the tip at least one meter above WXT520. The rod must be properly grounded, compliant with all applicable local safety regulations. VAISALA _______________________________________________________________________ 33 User’s Guide ______________________________________________________________________ Installation Procedure At the measurement site, WXT520 needs to be mounted, grounded, aligned, and connected to the data logger and the power source. Mounting Weather Transmitter WXT520 can be mounted either onto a vertical pole mast or onto a horizontal cross arm. When mounting WXT520 onto a pole mast, an optional mounting kit can be used to ease mounting. When using the optional mounting kit, alignment is needed only when mounted for the first time. Each of the mounting options is further described in the following sections. NOTE Weather Transmitter WXT520 must be installed to an upright, vertical position. Mounting to Vertical Pole Mast 1. Remove the screw cover and insert WXT520 to the pole mast. 2. Align the transmitter in such a way that the arrow points to north. 3. Tighten the fixing screw (provided) and replace the screw cover. 34 ___________________________________________________________________M210906EN-A Chapter 4 _______________________________________________________________ Installation 0803-030 Figure 12 Location of Fixing Screw Mounting with Mounting Kit (Optional) 1. Insert the mounting kit adapter to the transmitter bottom in the position shown in the picture. 2. Turn the kit inside the bottom firmly until you feel that the adapter snaps into the locked position. 3. Mount the adapter to the pole mast, do not tighten the fixing screw (provided). 4. Align the transmitter in such a way that the arrow points to north. 5. Tighten the fixing screw of the mounting adapter to fix the adapter firmly to the pole mast. VAISALA _______________________________________________________________________ 35 User’s Guide ______________________________________________________________________ 0803-031 Figure 13 Mounting WXT520 to Pole Mast Using Optional Mounting Kit The following numbers refer to Figure 13 on page 36: NOTE 1 = Mounting kit 2 = Fixing screw When removing WXT520 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. 36 ___________________________________________________________________M210906EN-A Chapter 4 _______________________________________________________________ Installation Mounting To Horizontal Cross Arm 1. Remove the screw cover. 2. Align the horizontal cross arm in south-north-direction, see Aligning WXT520 on page 41. In case the cross arm cannot be aligned, make the wind direction offset as instructed in section Wind Direction Offset on page 42. 3. Mount the transmitter into the cross arm by using a mounting bolt (M6 DIN933) and a nut, see Figure 14 on page 37 and Figure 15 on page 38. 0803-032 Figure 14 Mounting WXT520 to Cross Arm (L-Profile) The following numbers refer to Figure 14 on page 37: 1 = Nut (M6 DIN934) 2 = Mounting bolt (M6 DIN933) VAISALA _______________________________________________________________________ 37 User’s Guide ______________________________________________________________________ 0803-039 Figure 15 Mounting Bolt Location in Cross Arm The following numbers refer to Figure 15 on page 38: 1 = Nut (M6 DIN934) 2 = Mounting bolt (M6 DIN933) Grounding the WXT520 The normal way to ground the WXT520 is to install it on a mast or a cross arm that provides a good connection to earth ground. The grounding is provided via the fixing screw (or mounting bolt), so it is important that it makes a good ground connection. If the surface of the mounting point is painted or has some other finishing that prevents a good electrical connection, consider using the Bushing and Grounding Kit and a cable to provide the ground connection. Grounding using the Bushing and Grounding Kit If necessary, you can run a cable from the fixing screw to a grounding point. A Bushing and Grounding Kit (Vaisala order code: 222109) is available for this purpose. The kit includes a longer fixing screw, two nuts and washers, and an Abiko connector for the grounding cable. Refer to Figure 16 on page 39 for an illustration on how to assemble and install the kit. 38 ___________________________________________________________________M210906EN-A Chapter 4 _______________________________________________________________ Installation The kit does not include the grounding cable. Use a 16 mm2 (AWG 5) conductor to achieve a good ground connection. Figure 16 Grounding Using the Bushing and Grounding Kit The following numbers refer to Figure 16 on page 39: 1 = Fixing screw 2 = Nut 3 = Abiko connector between two washers Marine Grounding Jumper The WXT520 should be properly grounded also in marine applications. If it is grounded to the hull of a ship (ship’s ground) you must remove the grounding jumper inside the WXT520. When the jumper is removed, the signal ground is DC isolated from the chassis ground (> 500 VDC, fulfilling the marine EMC specifications), but AC surge currents will still be flowing, thus helping the WXT520 survive transient overvoltages. The jumper is located inside the transmitter, on the same component board as the screw terminals. The location of the jumper is indicated in Figure 17 on page 40. VAISALA _______________________________________________________________________ 39 User’s Guide ______________________________________________________________________ 0803-048 Figure 17 Grounding Jumper Location The following numbers refer to Figure 17 on page 40: 1 = Grounding jumper (remove for marine applications) To remove the jumper, you must open the transmitter. If you need to access the screw terminals, you should remove the jumper at the same time. 1. Loosen the three long screws at the bottom of WXT520. 2. Pull out the bottom part of the transmitter. 3. Remove the grounding jumper from the PCB. 4. Replace the bottom part and tighten the three screws. To make sure that the radiation shield stays straight, do not tighten the screws all the way in one go. Do not overtighten. 40 ___________________________________________________________________M210906EN-A Chapter 4 _______________________________________________________________ Installation Aligning WXT520 To help the alignment, there is an arrow and the text "North" on the bottom of the transmitter. WXT520 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 with a magnetic compass. The magnetic declination is the difference in degrees between the true north and magnetic north. The source for the magnetic declination should be current as the declination changes over time. 0003-011 Figure 18 Sketch of Magnetic Declination Compass Alignment To align the WXT520, proceed as follows: 1. 2. 3. If WXT520 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 WXT520 are exactly in line with the compass and that the arrow on the bottom of WXT520 points to the north. Tighten the fixing screw on the bottom of the transmitter when the bottom arrow is exactly aligned to north. VAISALA _______________________________________________________________________ 41 User’s Guide ______________________________________________________________________ Wind Direction Offset Make a wind direction offset in case WXT520 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 WXT520. 1. Mount the transmitter to a desired position, see section Mounting on page 34. 2. Define the deviation angle from the north-zero-alignment. Use the ± sign indication to express the direction from the north line (see example pictures). 3. Feed the deviation angle to the device by using the wind message formatting command aWU,D (direction offset), see section Checking the Settings (aWU) on page 107. 4. From now on, WXT520 transmits the wind direction data by using the changed zero-alignment. 0505-201 Figure 19 Wind Direction Offset 42 ___________________________________________________________________M210906EN-A Chapter 5 _______________________________________________ Wiring and Power Management CHAPTER 5 WIRING AND POWER MANAGEMENT This chapter provides you with instructions on how to connect the power supply and the serial interfaces, and how to manage and estimate the power consumption. WXT520 can be accessed through four different serial interfaces: RS232, 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. Only one serial interface can be used at a time. CAUTION The cable openings in the transmitter bottom assembly are covered with hexagonal rubber plugs. If you are not using the cable glands (included in the Bushing and Grounding Kit), keep the openings covered. Power Supplies Operating voltage Vin+: 5 ... 32 VDC Notice that for the average current consumption, see the graphs in Figure 20 on page 44. The minimum consumption graph is for SDI-12 standby mode. The input power supply shall be capable to deliver 60 mA (at 12 V) or 100 mA (at 6 V) instant current spikes with duration of 30 ms. These are drawn by the wind sensor (whenever enabled) at 4 Hz rate, which is the default value for wind sampling. Wind sampling at 2 Hz or 1 Hz rate is also available (see Chapter 8, Sensor and Data Message Settings, on page 107). The average current consumption will decrease almost in VAISALA _______________________________________________________________________ 43 User’s Guide ______________________________________________________________________ proportion to the sampling rate, since wind measurement is the most consuming operation in the system. In most occasions the average consumption is less than 10 mA. Typically, the higher the voltage the lower the current (see Figure 20 on page 44). 0805-023 Figure 20 Average Operational Current Consumption (with 4Hz Wind Sensor Sampling) Heating voltage Vh+ (one of the following three alternatives): - 5 ... 32 VDC; - AC, max Vpeak-to-peak 84 V; or - Full-wave rectified AC, max Vpeak 42 V. Typical DC voltage ranges are as follows: - 12 VDC ± 20 % (max 1.1 A); - 24 VDC ± 20 % (max 0.6 A). Maximum heating power is achieved at voltages 15.5 V and 32 V. Nominally at 15.7 V heating voltage level WXT520 automatically changes the heating element combination in order to consume equal 44 ___________________________________________________________________M210906EN-A Chapter 5 _______________________________________________ Wiring and Power Management power with 12 VDC and 24 VDC supplies. Input resistance (Rin) is radically increased with voltages above 16 V (see the following graph). The recommended ranges for AC or full-wave rectified AC are: - 68 Vp-p ± 20 % (max 0.6 A), for AC; - 34 Vp ± 20 % (max 0.6 A), for f/w rectified AC. 0805-22 Figure 21 Heating Current and Power vs Vh CAUTION To avoid exceeding the maximum ratings in any condition, the voltages must be checked with no load at the power supply output. WARNING Make sure that you connect only de-energized wires. VAISALA _______________________________________________________________________ 45 User’s Guide ______________________________________________________________________ Wiring Using the 8-pin M12 Connector External Wiring The 8-pin M12 connector is located on the bottom of the transmitter, see Figure 4 on page 21. The pins of the 8-pin M12 connector as seen from outside the transmitter are illustrated in the following figure. 0308-032 Figure 22 Pins of 8-pin M12 Connector The pin connections for the 8-pin M12 connector and the wire colors of the respective M12 cable (optional, 2/10 m) are listed in the table below. Table 1 Pin-outs for WXT520 Serial Interfaces and Power Supplies /------------------ Default wiring ------------------\ RS-422 wiring Wire Color M12 Pin# RS-232 SDI-12 RS-485 RS-422 Blue Gray White Green Pink Yellow 7 5 1 3 6 4 8 Data out (TxD) Data in (RxD) GND for data GND for Vh+ Vh+ (heating) GND for Vin+ Data in/out (Tx) Data in/out (Rx) GND for data GND for Vh+ Vh+ (heating) GND for Vin+ DataData+ GND for Vh+ Vh+ (heating) GND for Vin+ Data in (RX-) Data in (RX+) Data out (TX-) Data out (TX+) GND for Vh+ Vh+ (heating) GND for Vin+ 2 Vin+ (operating) Vin+ (operating) Vin+ (operating) Vin+ (operating) Red/Clear1 Brown 1. Red in the internal wiring, clear in the cable (a non-insulated drain wire) The signal names Data in (RxD) and Data out (TxD) in the table describe the direction of data flow as seen from WXT520. The terms "Default wiring" and "RS-422 wiring" refer to the two internal wiring options, see the diagrams on the next page. 46 ___________________________________________________________________M210906EN-A Chapter 5 _______________________________________________ Wiring and Power Management Internal Wiring The 8-pin M12 connector is wired for RS-232, SDI-12, and RS-485 modes by default. The 4-wire RS-422 requires a different internal wiring (see also Table 1 on page 46). Refer to the figure below if you need to change the wiring of the M12 connector. 0505-205 Figure 23 Internal Wiring The RS-232 interface can be accessed through the M12 connector using a standard PC serial port. Same applies to the SDI-12 interface, since the Rx and Tx lines are separate at the M12 connector. NOTE The true SDI-12 line requires that the Rx and Tx wires are joined together (outside WXT520). 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 WXT520. For testing purposes, the inverted output of either interface (screw terminal pin #3 TX-) is directly readable with PC's Received Data line. In this case Signal Ground for PC serial port is taken from screw terminal pin #6 SGND (for testing purposes pin #19 VIN- will also do). For configuration work, the Service Port is most practical, since it has constant and convenient line parameters: RS-232/19200, 8, N, 1. See Chapter 6, Connection Options, on page 55 and Figure 4 on page 21). VAISALA _______________________________________________________________________ 47 User’s Guide ______________________________________________________________________ Wiring Using the Screw Terminals 1. Loosen the three long screws at the bottom of WXT520. 2. Pull out the bottom part of the transmitter. 3. Insert the power supply wires and signal wires through the cable gland(s) in the bottom of the transmitter. Cable glands are included in the optional Bushing and Grounding Kit (order code 222109). 4. Connect the wires according to Table 2 on page 49. 5. Replace the bottom part and tighten the three screws. To make sure that the radiation shield stays straight, do not tighten the screws all the way in one go. Do not overtighten. 0803-035 Figure 24 Screw Terminal Block The following numbers refer to Figure 24 on page 48: 1 = Screw terminals 48 ___________________________________________________________________M210906EN-A Chapter 5 _______________________________________________ Wiring and Power Management Table 2 Screw Terminal Pin-outs for WXT520 Serial Interfaces and Power Supplies Screw Terminal Pin RS-232 SDI-12 RS-485 RS-422 1 RX2 RX+ 3 TX4 TX+ 5 RXD 6 SGND 17 HTG18 HTG+ 19 VIN20 VIN+ Data out (TxD) Data in (RxD) GND for data GND for Vh+ Vh+ (heating) GND for Vin+ Vin+ (operating) Data in/out (Tx) Data in/out (Rx) GND for data GND for Vh+ Vh+ (heating) GND for Vin+ Vin+ (operating) DataData+ DataData+ GND for Vh+ Vh+ (heating) GND for Vin+ Vin+ (operating) Data in (RX-) Data in (RX+) Data out (TX-) Data out (TX+) GND for Vh+ Vh+ (heating) GND for Vin+ 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 WXT520. 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. In the other modes the jumpers may stay or they can be removed. VAISALA _______________________________________________________________________ 49 User’s Guide ______________________________________________________________________ Data Communication Interfaces 0505-206 Figure 25 Data Communication Interfaces With RS-485 and RS-422 interfaces, termination resistors should be used at both ends of the line, if data rate is 9600 Bd or higher and distance is 600 m (2000 ft) or longer. Resistor range 100 ... 180 Ω is suitable for twisted pair lines. Resistors are connected across RX- to RX+ and across TX- to TX+ (with RS-485 only one resistor needed). The termination resistors will remarkably increase power consumption during data transmission. If low power consumption is a must, a 0.1 uF capacitor should be connected in series with each termination resistor. 50 ___________________________________________________________________M210906EN-A Chapter 5 _______________________________________________ Wiring and Power Management Note that the RS-485 interface can be used as well with four wires (as the RS-422). The basic difference between the RS-485 and RS-422 is actually their protocol. Namely, in the RS-422 mode the transmitter is held constantly enabled, while in the RS-485 mode it is enabled only during transmission (for allowing the host’s transmission in the twowire case). The RS-232 output swings only between 0 ... +4.5 V. This is enough for modern PC inputs.The recommended maximum for RS-232 line length is 100 m (300 ft) with 1200 Bd data rate. Higher rates require shorter distance, for instance 30 m (100 ft) with 9600 Bd. NOTE If you use the WXT520 on an RS-485 bus with other polled devices, always disable the error messaging feature. You can do this with the following command: 0SU,S=N<crlf>. Power Management The power consumption of the WXT520 varies significantly, depending on the selected operating mode or protocol, the data interface type, the sensor configuration, and the measurement and reporting intervals. Lowest consumption is achieved with the Native SDI-12 mode, typically about 1 mW in standby (0.1 mA @ 12 V), while with ASCII RS-232 or Continuous SDI-12 modes it is about 3 mW in standby. Any sensor measurement, while being activated, adds its own extra consumption to the standby power. Some hints for economic power management are given below. The current consumption values are all defined for 12 V supply. For 6 V supply, multiply the values by 1.9. For 24 V supply multiply the values by 0.65 (see Figure 20 on page 44). - Wind measurement is absolutely the most consuming operation in the system. So, it all depends on how the wind is to be reported. If long time averages are needed, the wind must be constantly measured - then it makes no big difference, which requesting period or mode is used. Fully continuous wind measurement with 4 Hz sampling rate adds 2 ... 5 mA to the standby current (depending on the wind and some other climatic conditions). But for instance 10-second average requested every 2 minutes consumes 12 times less. And 1 Hz sampling rate makes it further decrease to one fourth. VAISALA _______________________________________________________________________ 51 User’s Guide ______________________________________________________________________ - PTU measurement adds approximately 0.8 mA to the standby consumption. Each single measurement of PTU takes 5 seconds (including the warm-up period). This can be used for estimating the average consumption of PTU. - Continuous precipitation adds some 0.07 mA to the standby consumption. A single, isolated raindrop causes an additional 0.04 mA to the standby consumption, this condition lasting about 10 seconds (continued, if more raindrops are detected within the 10-second period). - ASCII RS-232 Standby consumption with baud rates 4800 and higher is typically 0.24 mA. With a low baud rate selection (1200 or 2400 Bd) this is reduced to less than 0.19 mA. The jumper wires across TX+/RX+ and TX-/RX- add an extra 0.02 mA (they are necessary only in 2-wire RS-485 mode). - ASCII RS-232 Polling mode and Automatic mode have equal consumption. Thus Automatic mode is a little more economic, since interpreting the poll takes more prosessing time than starting the Automatic message. However, care should be taken when selecting Precipitation Autosend mode, where the submodes M=R and M=C may cause extra consumption in rainy conditions, as triggered to send messages by the rain incidents. - ASCII RS-232 Data transmission adds 1 ... 2 mA to the standby consumption during the message sending time. Also it should be noted that the host device's input (data logger or PC) may constantly draw some current from the TX line. - RS-485 and RS-422 Data interfaces consume about the same as RS-232. But with long data cables the consumption during data transmission may be much higher, especially when termination resistors are used. 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. - SDI-12 Native mode (M=S, C=1) has the lowest standby consumption, about 0.1 mA. Note that it can also be used with RS232 terminals (PC or equivalent), see the SDI-12 connection diagram in Figure 25 on page 50. In this case the commands must be in SDI-12 format, but no special line break signals are required. The SDI-12 mode is for polling only. - SDI-12 Continuous mode (M=R) consumes about the same as the ASCII RS-232 mode. 52 ___________________________________________________________________M210906EN-A Chapter 5 _______________________________________________ Wiring and Power Management NOTE If Heating function is enabled, SDI-12 Native mode consumes the same as ASCII RS-232 mode. When heating is on (or temperature is such it should be on), some 0.08 mA additional current is drawn from the operational power supply. NOTE While in Service mode and/or while supplied through the Service port the WXT520 consumes 0.3 ... 0.6 mA more than in normal mode, when 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. This can also be seen in the supply voltage reading of the Supervisor message - the Vs value is 1V lower than the actual input voltage. VAISALA _______________________________________________________________________ 53 User’s Guide ______________________________________________________________________ 54 ___________________________________________________________________M210906EN-A Chapter 6 ________________________________________________________ Connection Options CHAPTER 6 CONNECTION OPTIONS This chapter contains instructions for configuring the communication with the transmitter. Communication Protocols As soon as WXT520 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. Table 3 Available Serial Communication Protocols Serial Interface Communication Protocols Available RS-232 ASCII automatic and polled NMEA 0183 v3.0 automatic and query SDI-12 v1.3 and SDI-12 v1.3 continuous measurement ASCII automatic and polled NMEA 0183 v3.0 automatic and query SDI-12 v1.3 and SDI-12 v1.3 continuous measurement ASCII automatic and polled NMEA 0183 v3.0 automatic and query SDI-12 v1.3 and SDI-12 v1.3 continuous measurement SDI-12 v1.3 and SDI-12 v1.3 continuous measurement RS-485 RS-422 SDI-12 You have chosen the communication protocol (ASCII, NMEA 0183 or SDI-12) when placing the order. In case you want to check and/or change the protocol or other communication settings, see the following sections. VAISALA _______________________________________________________________________ 55 User’s Guide ______________________________________________________________________ NOTE The RS-485 and RS-422 interfaces cannot be directly accessed with a standard PC terminal. They require a suitable converter. For accessing the RS-485 interface, you can use the USB RS-232/RS-485 Cable; see section Connection cables on page 56. NOTE RS-232 and SDI-12 can be accessed with a standard PC terminal, presuming that, for SDI-12, the Data in/out lines have not been combined inside WXT520. Connection cables The connection cable options for WXT520 are listed in the table below. The USB cables allow the transmitter to be connected to a PC using a standard USB port. The USB cables also provide operation power to the transmitter when connected. Note that USB cables do not provide power to the heating. Table 4 Connection Cable Options Cable Name Connector on Sensor End Connector on User End Order Code USB Service Cable (1.4m) M8 female USB type A USB Service Cable Adapter for WXT510/WMT50 USB RS232/RS485 Cable (1.4m) 2-meter Cable WXT510/WMT50 service connector M12 female M12 female M8 male 220614 (also includes Vaisala Configuration Tool software) 221523 10-meter Cable M12 female 10-meter extension cable 40-meter cable M12 male No connector; open end wires NOTE USB type A No connector; open end wires No connector; open end wires M12 female No connector; open end wires 220782 222287 222288 215952 217020 If you use the USB RS232/RS485 cable for a permanent installation, it is recommended that you use the WSP152 Surge Protector to protect the host PC against surges entering through the USB port. 56 ___________________________________________________________________M210906EN-A Chapter 6 ________________________________________________________ Connection Options Installing the Driver for the USB Cable Before taking the USB cable into use, you must install the provided USB driver on your PC. When installing the driver, you must acknowledge any security prompts that may appear. The driver is compatible with Windows 2000, Windows XP, Windows Server 2003, and Windows Vista. 1. Check that the USB cable is not connected. Disconnect the cable if you have already connected it. 2. Insert the media that came with the cable, or download the driver from www.vaisala.com. 3. Execute the USB driver installation program (setup.exe), and accept the installation defaults. The installation of the driver may take several minutes. 4. After the driver has been installed, connect the USB cable to a USB port on your PC. Windows will detect the new device, and use the driver automatically. 5. The installation has reserved a COM port for the cable. Verify the port number, and the status of the cable, using the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu. The reserved ports are also visible in the Ports section of the Windows Device Manager. Remember to use the correct port in the settings of your terminal program. Windows will recognize each individual cable as a different device, and reserve a new COM port. There is no reason to uninstall the driver for normal use. However, if you wish to remove the driver files and all Vaisala USB cable devices, you can do so by uninstalling the entry for Vaisala USB Instrument Driver from the Add or Remove Programs (Programs and Features in Windows Vista) in the Windows Control Panel. VAISALA _______________________________________________________________________ 57 User’s Guide ______________________________________________________________________ Service Cable Connection The USB Service Cable has a snap-on connector for the M8 connector of the service port. The service cable connection is recommended for checking and changing the device settings. When making the changes, use the Vaisala Configuration Tool or a standard PC terminal program. The USB service cable is included in the Service Pack 2, see Table 22 on page 143. For a picture of the service cable, see Figure 6 on page 22. When you connect the USB service cable between the service connector and PC USB port, the service port settings are forced automatically to RS-232 / 19200, 8, N, 1. At the same time, the main serial port at M12 connector and at screw terminals is disabled. 1. Make a connection between the USB port of your PC and the M8 service port connector on the bottom plate of the transmitter by using the USB service cable. See Figure 4 on page 21. 2. Open the Vaisala Configuration Tool, or a terminal program. 3. Select the COM port that has been reserved for the USB cable, and select the following default communication settings: 19200, 8, N, 1. NOTE 4. Use the Vaisala Configuration Tool or a terminal program to make the desired configuration changes. When working with a terminal program, see section Communication Setting Commands on page 59. 5. When removing the service cable, support the transmitter while pulling on the snap-on connector. The connection is tight, and it is possible to change the alignment of the transmitter if you pull too hard. Changes in the serial interface/communication protocol/baud settings take place when disconnecting the service cable or when resetting the transmitter. If these settings are not changed during the service connection session, the original main port settings (at M12 and screw terminals) are returned as soon as the service cable is disconnected from either end. 58 ___________________________________________________________________M210906EN-A Chapter 6 ________________________________________________________ Connection Options Connection Through M12 Bottom Connector or Screw Terminal Checking/changing the device settings can also be made through the M12 bottom connector or screw terminal. Then you have to have know the communication settings of the device, have a suitable cable between the device and the host and, if needed, use a converter (for example, RS485/422 to RS-232, if the host is a PC). The factory defaults settings are as follows: Table 5 Default Serial Communication Settings for M12/ Screw Terminal Connection Serial Interface Serial Settings SDI-12 RS-232, ASCII RS-485, ASCII RS-422 ASCII RS-422 NMEA 1200 baud, 7, E, 1 19200 baud, 8, N, 1 19200 baud, 8, N, 1 19200 baud, 8, N, 1 4800 baud, 8, N, 1 Communication Setting Commands NOTE Hereafter the commands to be typed are presented in normal text while the responses of the transmitter are presented in italic. VAISALA _______________________________________________________________________ 59 User’s Guide ______________________________________________________________________ Checking the Current Communication Settings (aXU) With this command you can request the current communication settings of WXT520. Command format in ASCII and NMEA 0183: aXU<cr><lf> Command format in SDI-12: aXXU! where a = Device address, which may consist of the following characters: 0 (default) ... 9, A ... Z, a ... z. XU = Device settings command in ASCII and NMEA 0183 XXU = Device settings command in SDI-12 <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 Example response in ASCII and NMEA 0183: aXU,A=a,M=[M],T=[T],C=[C],I=[I],B=[B],D=[D],P=[P],S=[S], L=[L],N=[N],V=[V]<cr><lf> Example response in SDI-12: aXXU,A=a,M=[M],T=[T],C=[C],I=[I],B=[B],D=[D],P=[P],S=[S], L=[L],N=[N],V=[V]<cr><lf> NOTE You can add the Id information field in the supervisor data message to provide identifying information in addition to the transmitter address. See section Supervisor Message on page 122. The information field is set as part of the factory settings (see General Unit Settings on page 164). You can only modify it using the Vaisala Configuration Tool. 60 ___________________________________________________________________M210906EN-A Chapter 6 ________________________________________________________ Connection Options Setting Fields a = Device address XU = Device settings command in ASCII and NMEA 0183 XXU = Device settings command in SDI-12 [A] = Address: 0 (default) ... 9, A ... Z, a ... z [M] = Communication protocol: A = ASCII, automatic a = ASCII, automatic with CRC P = ASCII, polled p = ASCII, polled, with CRC N = NMEA 0183 v3.0, automatic Q = NMEA 0183 v3.0, query (= polled) S = SDI-12 v1.3 R = SDI-12 v1.3 continuous measurement [T] = Test parameter (for testing use only) [C] = Serial interface: 1 = SDI-12, 2 = RS-232, 3= RS-485, 4 = RS-422 [I] = Automatic repeat interval for Composite data message:1 ... 3600 s, 0 = no automatic repeat [B] = Baud rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 [D] = Data bits: 7/8 [P] = Parity: O = Odd, E = Even, N = None [S] = Stop bits: 1/2 [L] = 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 WXT520. During the delay, the WXT520's transmitter is disabled. Effective in ASCII, polled and NMEA 0183 query protocols. Effective when RS-485 is selected (C = 3). [N] = Name of the device: WXT520 (read only) [V] = Software version: for example, 1.00 (read only) <cr><lf> = Response terminator VAISALA _______________________________________________________________________ 61 User’s Guide ______________________________________________________________________ NOTE There are two different SDI-12 modes available for providing all the functionality of the SDI-12 v1.3 standard. The lowest power consumption is achieved with the Native SDI-12 mode (aXU,M=S), as it makes measurements and outputs data only on request. In the continuous SDI-12 mode (aXU,M=R) internal measurements are made at a user-configurable update interval, see Chapter 8, Sensor and Data Message Settings, on page 107. The data is outputted on request. Example (ASCII and NMEA 0183, device address 0): 0XU<cr><lf> 0XU,A=0,M=P,T=0,C=2,I=0,B=19200,D=8,P=N,S=1,L=25, N=WXT520,V=1.00<cr><lf> Example (SDI-12, device address 0): 0XXU!0XXU,A=0,M=S,T=0,C=1,I=0,B=1200,D=7,P=E,S=1,L=25, N=WXT520,V=1.00<cr><lf> Changing the Communication Settings (aXU) Make the desired setting with the following command. Select the correct value/letter for the setting fields, see Setting Fields on page 61. See also the examples. 62 ___________________________________________________________________M210906EN-A Chapter 6 ________________________________________________________ Connection Options Command format in ASCII and NMEA 0183: aXU,A=x,M=x,C=x,I=x,B=x,D=x,P=x,S=x,L=x<cr><lf> Command format in SDI-12: aXXU,A=x,M=x,C=x,I=x,B=x,D=x,P=x,S=x,L=x! where NOTE A, M, C, I, = B, D, P, S,L The communication setting fields, see Setting Fields on page 61. x = Input value for the setting <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 When changing the serial interface and communication protocol, note the following: Each serial interface requires its specific wiring and/or jumper settings described in Chapter 5, Wiring and Power Management, on page 43. Change first the serial interface field C and then the communication protocol field M. Changing the serial interface to SDI-12 (C=1) will automatically change the baud settings to 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 66. VAISALA _______________________________________________________________________ 63 User’s Guide ______________________________________________________________________ Example (ASCII and NMEA 0183, device address 0): Changing the device address from 0 to 1: 0XU,A=1<cr><lf> 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=WXT520,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. Checking the actual settings: 0XU<cr><lf> 0XU,A=0,M=P,C=2,I=0,B=19200,D=8,P=N,S=1,L=25,N=WXT520, V=1.00<cr><lf> NOTE You can change several parameters in the same command as long as the command length does not exceed 32 characters (including command terminator characters ! or <cr><lf>).You do not have to type those setting fields that are not to be changed. Changing several settings with one command: 0XU,M=A,C=3,B=9600<cr><lf> 0XU,M=A,C=3,B=9600<cr><lf> Checking the changed settings: 0XU<cr><lf> 0XU,A=0,M=A,T=1,C=3,I=0,B=9600,D=8,P=N,S=1,L=25, N=WXT520,V=1.00<cr><lf> 64 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages CHAPTER 7 GETTING THE DATA MESSAGES This chapter presents the general and data message commands. Each communication protocol has its own section for data message commands. For changing the message parameters, units and other settings, see Chapter 8, Sensor and Data Message Settings, on page 107. NOTE Type commands in CAPITAL letters. NOTE The parameter order in messages is as follows: Wind (M1): Dn Dm Dx Sn Sm Sx PTU (M2): Ta Tp Ua Pa Rain (M3): Rc Rd Ri Hc Hd Hi Rp Hp Supv (M5): Th Vh Vs Vr Id Comp (M): Wind PTU Rain Supv (parameters in above order) The parameters are in the same order as in the Setting Field tables in chapter Sensor and Data Message Settings on page 107. The order of the parameters is fixed, but you can exclude any parameter from the list when configuring the transmitter. VAISALA _______________________________________________________________________ 65 User’s Guide ______________________________________________________________________ General Commands In case the error messaging is disabled (see Supervisor Message on page 122), WXT520 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. Command format in ASCII and NMEA 0183: aXZ<cr><lf> Command format in SDI-12: aXZ! where a = Device address XZ = 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> $WITXT,01,01,07,Start-up*29 66 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages Precipitation Counter Reset (aXZRU) This command is used to reset the rain and hail accumulation and duration parameters Rc, Rd, Hc, and Hd. Command format in ASCII and NMEA 0183: aXZRU<cr><lf> Command format in SDI-12: aXZRU! where a = Device address XZRU = Precipitation counter reset command <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 Example (ASCII): 0XZRU<cr><lf> 0TX,Rain reset<cr><lf> Example (SDI-12): 0XZRU!0<cr><lf> (= device address) Example (NMEA 0183): 0XZRU<cr><lf> $WITXT,01,01,10,Rain reset*26<cr><lf> VAISALA _______________________________________________________________________ 67 User’s Guide ______________________________________________________________________ Precipitation Intensity Reset (aXZRI) This command is used to reset the rain and hail intensity parameters Ri, Rp, Hi and Hp. Command format in ASCII and NMEA 0183: aXZRI<cr><lf> Command format in SDI-12: aXZRI! where NOTE a = Device address XZRI = Precipitation intensity reset command <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 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> 0TX,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> 68 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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 a = Device address XZM = Measurement break command <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 Example (ASCII): 0XZM<cr><lf> 0TX,Measurement reset<cr><lf> Example (SDI-12): 0XZM!0 (= device address) Example (NMEA 0183): 0XZM<cr><lf> $WITXT,01,01,09,Measurement reset*50<cr><lf> VAISALA _______________________________________________________________________ 69 User’s Guide ______________________________________________________________________ ASCII Protocol This section presents the data commands and data message formats for the ASCII communication protocols. Abbreviations and Units For changing the units, see Chapter 8, Sensor and Data Message Settings, on page 107. Table 6 Abbreviations and Units Abbreviation Name Unit Status1 Sn Sm Sx Dn Dm Dx m/s, km/h, mph, knots m/s, km/h, mph, knots m/s, km/h, mph, knots deg deg deg #,M, K, S, N #,M, K, S, N #,M, K, S, N #, D #, D #, D Pa Wind speed minimum Wind speed average Wind speed maximum Wind direction minimum Wind direction average Wind direction maximum Air pressure #, H, P, B, M, I Ta Tp Ua Rc Rd Ri Rp Hc Air temperature Internal temperature Relative humidity Rain accumulation Rain duration Rain intensity Rain peak intensity Hail accumulation hPa, Pa, bar, mmHg, inHg °C, °F °C, °F %RH mm, in s mm/h, in/h mm/h, in/h Hd Hi Hail duration Hail intensity Hp Hail peak intensity Th Vh Heating temperature Heating voltage #, S hits/cm h, hits/in h, hits/ #, M, I, H h hits/cm2h, hits/in2h, hits/ #, M, I, H h °C, °F #, C, F V #, N, V, W, F2 Vs Vr Id Supply voltage 3.5 V ref. voltage Information field V V alphanumeric hits/cm2, hits/in2, hits s 2 #, C, F #, C, F #, P #, M, I #, S #, M, I #, M, I #, M, I, H 2 V V 1. The letters in the status field indicate the Unit, the # character indicates invalid data. 2. For heating # = heating option is not available (has not been ordered). N = heating option is available but have been disabled by user or the heating temperature is over the high control limit. V = heating is on at 50% duty cycle and the heating temperature is between the high and middle control limits. W = heating is on at 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. 70 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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 b = Device address (default = 0) <cr><lf> = Response terminator. Example: ?<cr><lf> 0<cr><lf> If more than one transmitter is connected to the bus, see Appendix A, Networking, on page 147. If you need to change the device address, see Changing the Communication Settings (aXU) on page 62. 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 device to acknowledge its presence on the bus. Command format: a<cr><lf> where a = Device address <cr><lf> = Command terminator VAISALA _______________________________________________________________________ 71 User’s Guide ______________________________________________________________________ The response: a<cr><lf> where a = Device address <cr><lf> = Response terminator Example: 0<cr><lf> 0<cr><lf> Wind Data Message (aR1) With this command you can request the wind data message. Command format: aR1<cr><lf> where a = Device address R1 = Wind message query command <cr><lf> = Command terminator Example of the response (the parameter set is configurable): 0R1,Dn=236D,Dm=283D,Dx=031D,Sn=0.0M,Sm=1.0M, Sx=2.2M<cr><lf> where a = Device address R1 = Wind message query command Dn = Wind direction minimum (D = degrees) Dm = Wind direction average (D = degrees) Dx = Wind direction maximum (D = degrees) Sn = Wind speed minimum (M = m/s) Sm = Wind speed average (M = m/s) Sx = Wind speed maximum (M = m/s) <cr><lf> = Response terminator 72 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages To change the parameters and units in the response message and to make other sensor settings, see section Wind Sensor on page 107. Pressure, Temperature and Humidity Data Message (aR2) With this command you can request a pressure, temperature and humidity data message. Command format: aR2<cr><lf> where a = Device address R2 = Pressure, temperature and humidity message query command <cr><lf> = Command terminator Example of the response (the parameter set is configurable): 0R2,Ta=23.6C,Ua=14.2P,Pa=1026.6H<cr><lf> where a = Device address R2 = Pressure, temperature and humidity query command Ta = Air temperature (C = °C) Ua = Relative humidity (P = % RH) Pa = Air pressure (H = hPa) <cr><lf> = Response terminator To change the parameters and units in the response message and to make other sensor settings, see section Pressure, Temperature, and Humidity Sensors on page 113. VAISALA _______________________________________________________________________ 73 User’s Guide ______________________________________________________________________ Precipitation Data Message (aR3) With this command you can request the precipitation data message. Command format: aR3<cr><lf> where a = Device address R3 = Precipitation message query command <cr><lf> = Command terminator Example of the response (the parameter set is configurable): 0R3,Rc=0.0M,Rd=0s,Ri=0.0M,Hc=0.0M,Hd=0s,Hi=0.0M,Rp=0.0M, Hp=0.0M<cr><lf> where a = Device address R3 = Precipitation message query command Rc = Rain accumulation (M = mm) Rd = Rain duration (s = s) Ri = Rain intensity (M = mm/h) Hc = Hail accumulation (M = hits/cm2) Hd = Hail duration (s = s) Hi = Hail intensity (M = hits/cm2h) Rp = Rain peak intensity (M = mm/h) Hp = Hail peak intensity (M = hits/cm2h) <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 116. 74 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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 a = Device address R5 = 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,Id=HEL___<cr><lf > where a = Device address R5 = Supervisor message query command Th = Heating temperature (C = °C) Vh = Heating voltage (N = heating is off) Vs = Supply voltage (V = V) Vr = 3.5 V reference voltage (V = V) <cr><lf> = Response terminator Id = Information field To change the parameters and units in the response message and to make other settings, see section Supervisor Message on page 122. The content of the parameter "Id" is a text string which can be modified by using the Vaisala Configuration Tool only. Field can include customer-specific, additional information. For more information on changing the settings, refer to the Vaisala Configuration Tool on-line help for the Info field in the Device Settings window. VAISALA _______________________________________________________________________ 75 User’s Guide ______________________________________________________________________ Combined Data Message (aR) With this command you can request all individual messages aR1, aR2, aR3 and aR5 with just one command. Command format: aR<cr><lf> where a = Device address (default = 0) R = Combined message query command <cr><lf> = Command terminator Example of the response: 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,Id=HEL___<cr><lf > Composite Data Message Query (aR0) This command is used to request a combined data message with user configurable set of wind, pressure, temperature, humidity, precipitation and supervisor data. Command format: aR0<cr><lf> where a = Device address R0 = Composite data message query command <cr><lf> = Command terminator 76 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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, Rc=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 107. 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 threecharacter CRC before the command terminator. The response contains also a CRC. For more information about the CRC-computation see Appendix C, CRC-16 Computation, on page 159. Requesting a wind data message with a CRC: Command format: ar1xxx<cr><lf> where a = Device address r1 = Wind message query command xxx = Three-character CRC for ar1 command <cr><lf> = Command terminator Example of the response (the parameter set is configurable): 0r1,Dn=236D,Dm=283D,Dx=031D,Sn=0.0M,Sm=1.0M,Sx=2.2MLFj <cr><lf> where the three characters before <cr><lf> are the CRC for the response. NOTE The correct CRC for each command can be requested by typing the command with an arbitrary three-character CRC. VAISALA _______________________________________________________________________ 77 User’s Guide ______________________________________________________________________ Example of asking the CRC for the wind data message query ar1: Command format: ar1yyy<cr><lf> where a = Device address r1 = Wind message query command yyy = Arbitrary three-character CRC <cr><lf> = Command terminator Response: atX,Use chksum GoeIU~<cr><lf> where a = Device address tX,Use chksum = Text prompt Goe = Correct three-character CRC for the ar1 command IU~ = Three-character CRC for the response message <cr><lf> = Response terminator Example of the other data query commands with CRC (when the device address is 0): Pressure, humidity and temperature message query = 0r2Gje<cr><lf> Precipitation query = 0r3Kid<cr><lf> Supervisor query = 0r5Kcd<cr><lf> Combined message query = 0rBVT<cr><lf> Composite data message query = 0r0Kld<cr><lf> In every case the response contains a three-character CRC before the <cr><lf>. For selecting the parameters to be included in the response messages, changing the units and making other configurations of the measured parameters, see Chapter 8, Sensor and Data Message Settings, on page 107. 78 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages Automatic Mode When automatic ASCII protocol is selected the transmitter sends data messages at user configurable update intervals. The message structure is same as with data query commands aR1, aR2, aR3 and aR5. You can choose an individual update interval for each sensor, see Chapter 8, Sensor and Data Message Settings, on page 107, sections Changing the Settings. 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. Automatic Composite Data Message (aR0) When automatic composite data messaging is selected, the transmitter sends composite data messages at user configurable intervals. 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 _______________________________________________________________________ 79 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 107. Automatic composite data messaging is a concurrent, not an alternate mode to either the polled or automatic modes. SDI-12 Protocol There are two different modes available for providing all the functionality of the SDI-12 v1.3 standard. The lowest power consumption is achieved with the Native SDI-12 mode (aXU,M=S), as it makes measurements and outputs data only when requested. In this mode all the commands presented in this chapter are available except those for the Continuous measurement. In the Continuous mode (aXU,M=R) measurements are made at userconfigurable update intervals, see Chapter 8, Sensor and Data Message Settings, on page 107. The data is outputted on request. In this mode all the commands presented in this chapter are available. For changing the message parameters, units and other settings, see Chapter 8, Sensor and Data Message Settings, on page 107. In the Native SDI-12 mode (aXU,M=S) the WXT520 is in idle state most of the time (power consumption < 1 mW). More power is consumed only during the measurements and data transmit requested by the host device. Especially, the wind measurement typically consumes 60 mW average power (with 4 Hz sampling rate), throughout the averaging period. In the Continuous mode (aXU=M,R) the power consumption is determined by the internal update intervals of the sensors and wind averaging time. These have certain limits, so very long measurement intervals can not be achieved with this mode. Also the power consumption between the measurements is about three times that of the Native mode. 80 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages Address Query Command (?) 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 The response: a<cr><lf> where a = 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. Command format: a! where a = Device address ! = Command terminator VAISALA _______________________________________________________________________ 81 User’s Guide ______________________________________________________________________ The response: a<cr><lf> where a = Device address <cr><lf> = Response terminator Example: 0!0<cr><lf> Change Address Command (aAb) This command changes the device address. After the command has been issued and responded to, the sensor is not required to respond to another command for one second time in order to ensure writing the new address to the non-volatile memory. Command format: aAb! where a = Device address A = Change address command b = Address to change to ! = Command terminator The response: b<cr><lf> where b = Device address = the new address (or the original address, if the device is unable to change it) <cr><lf> = Response terminator Example (changing address from 0 to 3): 0A3!3<cr><lf> 82 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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! where a = Device address I = Send identification command ! = Command terminator The response: a13ccccccccmmmmmmvvvxxxxxxxx<cr><lf> where a = Device address 13 = 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 vvv = 3 characters specifying the firmware version xxxxxxxx = 8-character serial number <cr><lf> = Response terminator Example: 0I!013VAISALA_WXT520103Y2630000<cr><lf> Start Measurement Command (aM) This command asks the device to make a measurement. The measured data are not sent automatically and should be requested with a separate Send data command aD. VAISALA _______________________________________________________________________ 83 User’s Guide ______________________________________________________________________ The host device is not allowed to send any commands to other devices on the bus until the measurement is completed. When several devices are connected to the same bus and simultaneous measurements from the different devices are needed, Start concurrent measurement aC or Start concurrent measurement with CRC aCC should be used, see the next sections. See Examples of aM, aC and aD Commands on page 88. Command format: aMx! where a = Device address M = Start measurement command x = The desired sensor to make the measurement 1 = Wind 2 = Temperature, humidity, pressure 3 = Precipitation 5 = Supervisor If x is left out, the query refers to the combined data message used for requesting data from several sensors with just one command. See Examples of aM, aC and aD Commands on page 88. ! = Command terminator The response is sent in two parts: The response part one: atttn<cr><lf> The response part two (indicates that the data is ready to be requested): a<cr><lf> where a = Device address ttt = The measurement completing time in seconds n = The number of the measured parameters available (maximum number is 9) <cr><lf> = Response terminator 84 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages NOTE For changing the message parameters, units and other settings, see Chapter 8, Sensor and Data Message Settings, on page 107. NOTE When the measurement takes less than one second, the response part two is not sent. In WXT520 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). If more parameters are to be measured, Start concurrent measurement commands aC and aCC should be used (for which the maximum number of parameters to be measured is 20), see the following sections. Start Measurement Command with CRC (aMC) Command format: aMCx! This command has the same function as the aM 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. Start Concurrent Measurement (aC) This command is used when there are several devices on the same bus and simultaneous measurements are needed from the devices, or if more than nine (9) measurement parameters are requested from a single device. The measured data is not sent automatically and it should be requested with separate Send data command aD. See Examples of aM, aC and aD Commands on page 88. VAISALA _______________________________________________________________________ 85 User’s Guide ______________________________________________________________________ Command format: aCx! where a = Device address C = Start concurrent measurement command x = The desired measurement 1 = Wind 2 = Temperature, humidity and pressure 3 = Precipitation 5 = Supervisor If x is left out, the query refers to combined data message in which the user can request data from several sensors with just one command. See the examples below. ! = Command terminator The response: atttnn<cr><lf> where NOTE a = Device address ttt = The measurement completing time in seconds nn = The number of the measured parameters available (maximum number is 20) <cr><lf> = Response terminator For changing the message parameters, units and other settings, see Chapter 8, Sensor and Data Message Settings, on page 107. Start Concurrent Measurement with CRC (aCC) Command format: aCCx! This command has the same function as aC but a three-character CRC is added to the response data strings before <cr><lf>. 86 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages In order to request the measured data, Send data command aD should be used, see the following sections. 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 88. 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. If all the parameters are not retrieved in a single response message, repeat the Send data commands until all the data is obtained. Command format: aDx! where a = Device address D = Send data command x = The order of consecutive Send data commands. Always, the first Send data command should be addressed with x=0. If all the parameters are not retrieved, the next Send data command is sent with x=1 and so on. The maximum value for x is 9. See Examples of aM, aC and aD Commands on page 88. ! = Command terminator The response: a+<data fields><cr><lf> where a = Device address <data fields> = The measured parameters in selected units, separated with '+' marks (or - marks in case of negative parameter values). <cr><lf> = Response terminator VAISALA _______________________________________________________________________ 87 User’s Guide ______________________________________________________________________ NOTE aD0 command can also be used to break the measurement in progress started with commands aM, aMC, aC or aCC. NOTE In SDI-12 v1.3 Continuous measurement mode (aXU,M=R) the sensor makes measurements at configurable update intervals. The aD command following the aM, aMC, aC or aCC command always returns the latest updated data. Thus in aXU,M=R mode issuing consecutive aD commands may result in different data strings if the value(s) happen to be updated between the commands. Examples of aM, aC and aD Commands NOTE The parameter order in messages is as follows: Wind (M1): Dn Dm Dx Sn Sm Sx PTU (M2): Ta Tp Ua Pa Rain (M3): Rc Rd Ri Hc Hd Hi Rp Hp Supv (M5): Th Vh Vs Vr Id Comp (M): Wind PTU Rain Supv (parameters in above order) The parameters are in the same order as in the Setting Field tables in chapter Sensor and Data Message Settings on page 107. The order of the parameters is fixed, but you can exclude any parameter from the list when configuring the transmitter. The device address is 0 in all examples. Example 1: Start a wind measurement and request the data (all six wind parameters are enabled in the message): 0M1!00036<cr><lf> (measurement ready in 3 seconds and 6 parameters available) 0<cr><lf> (measurement completed) 0D0!0+339+018+030+0.1+0.1+0.1<cr><lf> 88 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages Example 2: 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> 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> (measurement completed) 0D0!0+34.3+10.5+10.7+3.366DpD<cr><lf> Example 5: Start a composite measurement and request the data. The configuration of the parameter set is such that nine (9) parameters are available. Thus start measurement command aM can be used. Due to the 35-character limit in response message, aD0 returns only six parameters. The remaining parameters are retrieved with aD1. 0M!00059<cr><lf> (measurement ready in 5 seconds and 9 parameters available) 0<cr><lf> (measurement completed) 0D0!0+340+0.1+23.7+27.9+1009.3+0.15<cr><lf> 0D1!0+0.0+0+0.0<cr><lf> VAISALA _______________________________________________________________________ 89 User’s Guide ______________________________________________________________________ Example 6: Start a composite measurement and request the data. The configuration of the parameter set is such that 20 parameters are available. Thus Start concurrent measurement command aC shall be used. Due to the 75character limit in response message, aD0 returns only 14 parameters. The remaining parameters are retrieved with aD1. 0C!000520<cr><lf> (measurement ready in 5 seconds and 20 parameters available, for aC command device address not sent as a sign of a completed measurement)) 0D0!0+069+079+084+0.1+0.6+1.1+21.1+21.7+32.0+1000.3+0.02 +20+0.0+0.0<cr><lf> 0D1!0+0+0.0+1.3+0.0+0+77.1<cr><lf> Continuous Measurement (aR) The device can be configured so that all the parameters can be requested instantly with the command aR instead of the two phase request procedure of commands aM, aMC, aC, aCC + aD. In this case the obtained parameter values are those from the latest internal updating (for setting of update intervals, see Chapter 8, Sensor and Data Message Settings, on page 107). NOTE For using Continuous measurement commands for all WXT520 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). 90 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages Command format: aRx! where a = Device address R = Start continuous measurement command: x = The desired sensor to make the measurement: 1 = Wind 2 = Temperature, humidity, pressure 3 = Precipitation 5 = Supervisor If x is left out, the query refers to the combined data message used for requesting data from several sensors with just one command. ! = Command terminator The response: a+<data fields><cr><lf> where a = Device address <data fields> = The measured parameters in selected units, separated with '+' marks (or '-' marks in case of negative parameter values). The maximum number of parameters to be measured with one reqeust is 15. <cr><lf> = Response terminator Examples (device address 0): 0R1!0+323+331+351+0.0+0.4+3.0<cr><lf> 0R3!0+0.15+20+0.0+0.0+0+0.0+0.0+0.0<cr><lf> 0R!0+178+288+001+15.5+27.4+38.5+23.9+35.0+1002.1+0.00+0+ 0.0+23.8<cr><lf> VAISALA _______________________________________________________________________ 91 User’s Guide ______________________________________________________________________ Continuous Measurement with CRC (aRC) Command format: aRCx! Has the same function as the Continuous measurement command aR but a three-character CRC is added to the response data strings before <cr><lf>. 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 WXT520. The selfdiagnostic data can be requested with aM5 command. NMEA 0183 V3.0 Protocol This section presents the data query commands and data message formats for the NMEA 0183 v3.0 query and automatic protocols. For changing the message parameters, units and other settings, see Chapter 8, Sensor and Data Message Settings, on page 107. A two-character checksum (CRC) field is transmitted in all data request sentences. For definition of the CRC, see Appendix C, CRC-16 Computation, on page 159. Device Address (?) This command is used to query the address of the device on the bus. Command format: ?<cr><lf> where ? <cr><lf> = Device address query command = Command terminator 92 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages The response: b<cr><lf> where b = Device address (default = 0) <cr><lf> = Response terminator. Example: ?<cr><lf> 0<cr><lf> If more than one transmitter is connected to the bus, see Appendix A, Networking, on page 147. If you need to change the device address, see Changing the Communication Settings (aXU) on page 62. 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 a = Device address <cr><lf> = Command terminator The response: a<cr><lf> where a = Device address <cr><lf> = Response terminator VAISALA _______________________________________________________________________ 93 User’s Guide ______________________________________________________________________ Example: 0<cr><lf> 0<cr><lf> MWV Wind Speed and Direction Query Request the wind speed and direction data with a MWV query command. For using MWV query the NMEA Wind formatter parameter in the wind sensor settings shall be set to W (see section Wind Sensor on page 107). With MWV query only wind speed and direction average values can be requested. For obtaining min and max data for speed and direction, see section XDR Transducer Measurement Query on page 95. Command format: $--WIQ,MWV*hh<cr><lf> where $ = Start of the message -- = Device identifier of the requester WI = Device type identifier (WI = weather instrument) Q = Defines the message as Query MWV = Wind speed and direction query command * = Checksum delimiter hh = Two-character checksum for the query command. <cr><lf> = Command terminator The response format: $WIMWV,x.x,R,y.y,M,A*hh<cr><lf> where $ = Start of the message WI = Talker identifier (WI = weather instrument) MWV = Wind speed and direction response identifier x.x = Wind direction value1 94 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages R = Wind direction unit (R = relative) y.y = Wind speed value M = Wind speed unit (m/s) A = Data status: A = valid, V = Invalid * = Checksum delimiter hh = Two-character checksum for the response <cr><lf> = Response terminator 1. Wind direction is given in relation to the devices north-south axis. An offset value to the measured direction can be set, see section 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 WXT520 by typing any three characters after the $--WIQ,MWV command. Example: Typing the command $--WIQ,MWVxxx<cr><lf> (xxx arbitrary characters) WXT520 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) XDR Transducer Measurement Query XDR query command outputs the data of all other sensors except wind. When requesting also wind data with the XDR command the NMEA Wind formatter parameter in the wind sensor settings shall be set to T (see section Wind Sensor on page 107). VAISALA _______________________________________________________________________ 95 User’s Guide ______________________________________________________________________ Command format: $--WIQ,XDR*hh<cr><lf> where $ = Start of the message -- = Device identifier of the requester WI = Device type identifier (WI = weather instrument) Q = Defines the message as Query XDR = Transducer measurement command * = Checksum delimiter hh = Two-character checksum for the query command. <cr><lf> = Command terminator The response includes the parameters activated in the data messages (see Chapter 8, Sensor and Data Message Settings, on page 107). NOTE The parameter order in the output is as shown in the parameter selection setting field, see Chapter 8, sections Setting the Fields. The response format: $WIXDR,a1,x.x1,u1,c--c1, ... ... ..an,x.xn,un,c--cn*hh<cr><lf> where $ = Start of the message WI = Device type identifier (WI = weather instrument) XDR = Transducer measurement response identifier a1 = Transducer type for the first transducer, see the following transducer table. x.x1 = Measurement data from the first transducer u1 = Units of the first transducer measurement, see the following transducer table. c--c1 = First transducer identification (id). WXT520's address aXU,A is added as a base number to the transducer id. For changing the address, see Checking the Current Communication Settings (aXU) on page 60 (command aXU,A= [0 ... 9/A ... Z/ a ... z]1. 96 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages ... an = Transducer type for the transducer n, see the following transducer table. x.xn = Measurement data from the transducer n un = Units of the transducer n measurement, see the following transducer table. c--cn = Transducer n id. WXT520'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 ... z]1. * = Checksum delimiter hh = Two-character checksum for the response <cr><lf> = Response terminator 1. NMEA-format transmits only numbers as transducer ids. If WXT520 address is given as a letter, it will be shown as a number (0 ... 9, A = 10, B = 11, a = 36, b = 37 etc.) The checksum to be typed in the query depends on the device identifier characters and can be asked from WXT520, see example below. Example: Typing the command $--WIQ,XDRxxx<cr><lf> (xxx arbitrary characters) WXT520 responds $WITXT,01,01,08,Use chksum 2D*72<cr><lf> indicating that 2D is the correct checksum for the $--WIQ,XDR command. If there are several distinct measurements of the same parameter (according to the transducer table below), they are assigned with different transducer ids. For example, minimum, average and maximum wind speed are measurements of the same parameter (wind speed) so if all three are configured to be shown in the XDR message, they get transducer ids A, A+1 and A+2, respectively, where A is WXT520 address aXU,A. The same applies for the wind direction. Temperature, internal temperature and heating temperature have the same unit, thus they are assigned with transducer ids A, A+1 and A+2, respectively. Accumulation, duration and intensity for rainfall and hails are measurements of the same parameters so they get transducer ids A for VAISALA _______________________________________________________________________ 97 User’s Guide ______________________________________________________________________ rainfall and A+1 for hails. Rain and hail peak intensities are assigned with transducer ids A+2 and A+3, respectively. For example, for a WXT520 with device address 0 the transducer ids of all the measurement parameters are as follows: Table 7 Transducer IDs of the Measurement Parameters Measurement Transducer ID Wind direction min Wind direction average Wind direction max Wind speed min Wind speed average Wind speed max Pressure Air temperature Internal temperature Relative humidity Rain accumulation Rain duration Rain current intensity Hail accumulation Hail duration Hail current intensity Rain peak intensity Hail peak intensity Heating temperature Supply voltage Heating voltage 3.5 V reference voltage Information field 0 1 2 0 1 2 0 0 1 0 0 0 0 1 1 1 2 3 2 0 1 2 4 Example of the XDR Query (all parameters of each sensor enabled and NMEA wind formatter set to T): $--WIQ,XDR*2D<cr><lf> 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> 98 ___________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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,20.4,C,2,U,12.0,N,0,U,12.5,V,1,U,3.460,V,2,G,HEL/ ___,,4*2D The structure of the wind sensor response message: where $ = Start of the message WI = Device type (WI = weather instrument) XDR = Transducer measurement response identifier A = Transducer id 0 type (wind direction), see the following Transducer table 302 = Transducer id 0 data (min wind direction) D = Transducer id 0 units (degrees, min wind direction) 0 = Transducer id for min wind direction A = Transducer id 1 type (wind direction) 320 = Transducer id 1 data (average wind direction) D = Transducer id 1 units (degrees, average wind direction) 1 = Transducer id for average wind direction A = Transducer id 2 type (wind direction) 330 = Transducer id 2 data (max wind direction) D = Transducer id 2 units (degrees, max wind direction) 2 = Transducer id for max wind direction S = Transducer id 0 type (wind speed) 0.1 = Transducer id 0 data (min wind speed) M = Transducer id 0 units (m/s, min wind speed) 0 = Transducer id for min wind speed VAISALA _______________________________________________________________________ 99 User’s Guide ______________________________________________________________________ S = Transducer id 1 type (wind speed) 0.2 = Transducer id 1 data (average wind speed) M = Transducer id 1 units (m/s, average wind speed) 1 = Transducer id for average wind speed S = Transducer id 2 type (wind speed) 0.2 = Transducer id 2 data (max wind speed) M = Transducer id 2 units (m/s, max wind speed) 2 = Transducer id for max wind speed * Checksum delimiter 57 = Two-character checksum for the response <cr><lf> = Response terminator The structure of the pressure, temperature and humidity sensor response message: where $ = Start of the message WI = Device type (WI = weather instrument) XDR = Transducer measurement response identifier C = Transducer id 0 type (Temperature), see the following Transducer table 23.3 = Transducer id 0 data (Temperature) C = Transducer id 0 units (C, Temperature) 0 = Transducer id for Temperature C = Transducer id 1 type (temperature) 23.3 = Transducer id 1 data (Tp internal temperature) C = Transducer id 1 units (C, Tp internal temperature) 1 = Transducer id for Tp internal temperature H = Transducer id 0 type (Humidity) 50.1 = Transducer id 0 data (Humidity) P = Transducer id 0 units (%, Humidity) 0 = Transducer id for Humidity P = Transducer id 0 type (Pressure) 1009.1 = Transducer id 0 data (Pressure) 100 __________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages H = Transducer id 0 units (hPa, Pressure) 0 = Transducer id for Pressure * Checksum delimiter 75 = Two-character checksum for the response <cr><lf> = Response terminator The structure of the precipitation sensor response message: where $ = Start of the message WI = Device type (WI = weather instrument) XDR = Transducer measurement response identifier V = Transducer id 0 type (Accumulated rainfall), see the following Transducer table 0.02 = Transducer id 0 data (Accumulated rainfall) I = Transducer id 0 units (mm, Accumulated rainfall) 0 = Transducer id for Accumulated rainfall Z = Transducer id 0 type (Rain duration) 30 = Transducer id 0 data (Rain duration) s = Transducer id 0 units (s, Rain duration) 0 = Transducer id for Rain duration R = Transducer id 0 type (Rain intensity) 2.7 = Transducer id 0 data (Rain intensity) M = Transducer id 0 units (mm/h, Rain intensity) 0 = Transducer id for Rain intensity V = Transducer id 1 type (Hail accumulation) 0.0 = Transducer id 1 data (Hail accumulation) M = Transducer id 1 units (hits/cm2, Hail accumulation) 1 = Transducer id for Hail accumulation Z = Transducer id 1 type (Hail duration) 0 = Transducer id 1 data (Hail duration) s = Transducer id 1 units (s, Hail duration) 1 = Transducer id for Hail duration VAISALA ______________________________________________________________________ 101 User’s Guide ______________________________________________________________________ R = Transducer id 1 type (Hail intensity) 0.0 = Transducer id 1 data (Hail intensity) M = Transducer id 1 units (hits/cm2h, Hail intensity) 1 = Transducer id for Hail intensity R = Transducer id 1 type (Rain peak intensity) 6.3 = Transducer id 1 data (Rain peak intensity) M = Transducer id 1 units (mm/h, Rain peak intensity) 2 = Transducer id for Rain peak intensity R = Transducer id 1 type (Hail peak intensity) 0.0 = Transducer id 1 data (Hail peak intensity) M = Transducer id 1 units (hits/cm2, Hail peak intensity) 3 = Transducer id for Hail peak intensity * Checksum delimiter 51 = Two-character checksum for the response <cr><lf> = Response terminator The structure of the supervisor response message: where $ = Start of the message WI = Device type (WI = weather instrument) XDR = Transducer measurement response identifier C = Transducer id 2 type (temperature), see the following Transducer table 20.4 = Transducer id 2 data (Heating temperature) C = Transducer id 2 units (C, Heating temperature) 2 = Transducer id for Heating temperature U = Transducer id 0 type (voltage) 12.0 = Transducer id 0 data (Heating voltage) M = Transducer id 0 units (N = heating disabled or heating temperature too high1, Heating voltage) 0 = Transducer id for Heating voltage U = Transducer id 1 type (Supply voltage) 102 __________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages 12.5 = Transducer id 1 data (Supply voltage) V = Transducer id 1 units (V, Supply voltage) 1 = Transducer id for Supply voltage U = Transducer id 2 type (voltage) 3.460 = Transducer id 2 data (3.5V reference voltage) V = Transducer id 2 units (V, 3.5V reference voltage) 2 = Transducer id for 3.5V reference voltage G = Transducer id 4 type (generic) HEL/___ = Transducer id 4 data (info field) Transducer id 4 units (none, null) 4 = * Transducer id for generic field Checksum delimiter 2D = Two-character CRC for the response. <cr><lf> = Response terminator 1. See Chapter 8, section Supervisor Message, Setting Fields for definitions of the Heating voltage field. Table 8 Transducer Table Transducer Type Units Field Temperature C Angular displacement (wind direction) Wind speed A C = Celsius F = Fahrenheit D = degrees S K = km/h, M = m/s, N = knots Pressure Humidity Accumulated precipitation Time (duration) Intensity (flow rate) P H V B = bars, P = Pascal P = Percent M = mm, I = in, H = hits Z R Voltage U S = seconds M = mm/h, I = in/h, H = hits/h for rainfall M = hits/cm2h, I = hits/in2h, H = hits/h for hails V = volts (also 50 % duty cycle for heating) Generic G Comments S = mph, non-standardized1 H = hPa, I = inHg, M = mmHg non-standardized1 non-standardized1 non-standardized1 N = not in use, F = 50% duty cycle for heating, W = full power for heating None (null) P=Percent 1. Not specified in the NMEA 0183 Standard. VAISALA ______________________________________________________________________ 103 User’s Guide ______________________________________________________________________ TXT Text Transmission These short text messages and their interpretation are shown in Table 11 on page 134. The text transmission response format: $WITXT,xx,xx,xx,c--c*hh<cr><lf> where $ = Start of the message WI = Talker identifier (WI = weather instrument) TXT = Text transmission identifier. xx = Total number of messages, 01 to 99 xx = Message number. xx = Text identifier (see text message table) c---c = Text message (see text message table) * Checksum delimiter hh = Two-character checksum for the query command. <cr><lf> = Response terminator Examples: $WItXT,01,01,01,Unable to measure error*6D<cr><lf> (wind data request when all the wind parameters were disabled from the wind message). $WITXT,01,01,03,Unknown cmd error*1F (unknown command 0XO!<cr><lf>). $WITXT,01,01,08,Use chksum 2F*72 (wrong checksum used in MWV query command) 104 __________________________________________________________________M210906EN-A Chapter 7 __________________________________________________ Getting the Data Messages Automatic Mode When NMEA 0183 v3.0 automatic protocol is selected, the transmitter sends data messages at user configurable update intervals. The message format is the same as in the MWV and XDR data queries. The NMEA wind formatter parameter in the wind sensor settings determines whether the wind messages are sent in MWV or XDR format. You can use ASCII data query commands aR1, aR2, aR3, aR5, aR, aR0 and their CRC-versions ar1, ar2, ar3, ar5, ar and ar0 also in NMEA 0183 protocol. The responses to these commands will be in standard NMEA 0183 format. For formatting the messages, see Chapter 8, Sensor and Data Message Settings, on page 107. Automatic Composite Data Message (aR0) When automatic composite data messaging is selected, the transmitter sends composite data messages at user configurable intervals. 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. Example (the parameters included can be chosen from the full parameter set of the commands aR1, aR2, aR3 and aR5): $WIXDR,A,057,D,1,S,0.6,M,1,C,22.6,C,0,H,27.1,P,0,P,1013.6,H,0,V, 0.003,I,0,U,12.0,N,0,U,12.4,V,1*67<cr><lf> Example (rain and voltage parameters removed): $WIXDR,A,054,D,1,S,0.4,M,1,C,22.5,C,0,H,26.3,P,0,P,1013.6,H,0*79 <cr><lf> For selecting the parameter set in the response message, see Chapter 8, Sensor and Data Message Settings, on page 107. Automatic composite data messaging is a concurrent, not an alternate mode to either the polled or automatic modes. VAISALA ______________________________________________________________________ 105 User’s Guide ______________________________________________________________________ 106 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings CHAPTER 8 SENSOR AND DATA MESSAGE SETTINGS This chapter presents the sensor configuration and data message formatting commands for all communications protocols: 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 Table 22 on page 143. Wind Sensor Checking the Settings (aWU) With the following command you can check the current wind sensor settings. Command format in ASCII and NMEA 0183: aWU<cr><lf> Command format in SDI-12: aXWU! VAISALA ______________________________________________________________________ 107 User’s Guide ______________________________________________________________________ where a = Device address WU = Wind sensor settings command in ASCII and NMEA 0183 XWU = 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],G=[G],U=[U],D=[D],N=[N],F=[F]<cr> <lf> The response in SDI-12: aXWU,R=[R],I=[I],A=[A],G=[G],U=[U],D=[D],N=[N],F=[F]<cr ><lf> where [R][I][A][G][U][D][N] are the setting fields, see the following sections. Example (ASCII and NMEA 0183, device address 0): 0WU<cr><lf> 0WU,R=01001000&00100100,I=60,A=10,G=1,U=N,D= 90,N=W,F=4<cr><lf> Example (SDI-12, device address 0): 0XWU!0XWU,R=11111100&01001000,I=10,A=3,G=1,U=M,D=0,N =W,F=4<cr><lf> 108 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings Setting Fields [R] = Parameter selection: This field consists of 16 bits defining the wind 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 parameters in the data message obtained with the following commands: -ASCII: aR1 and ar1 -NMEA 0183: $--WIQ,XDR*hh -SDI-12: aM1, aMC1, aC1, and aCC1 -SDI-12 continuous: aR1 and aRC1 1st bit (most left) 2nd bit 3rd bit 4th bit 5th bit 6th bit 7th bit 8th bit & The bits 9-16 determine the 9th bit wind parameters in the 10th bit composite data message 11th bit obtained with the following 12th bit commands: 13th bit -ASCII: aR0, ar0 14th bit -NMEA 0183: aR0, ar0 -SDI-12: aM, aMC, aC, and aCC 15th bit -SDI-12 continuous: aR and 16th bit (most right) aRC Dn Direction minimum Dm Direction average Dx Direction maximum Sn Speed minimum Sm Speed average Sx Speed maximum spare spare delimiter Dn Wind direction minimum Dm Wind direction average Dx Wind direction maximum Sn Speed minimum Sm Speed average Sx Speed maximum spare spare [I] = Update interval: 1 ... 3600 seconds [A] = Averaging time: 1 ... 3600 seconds Defines the period over which the wind speed and direction averaging is calculated. Same period is also used for maximum and minimum calculation. See also Appendix D Wind Measurement Averaging Method on page 161 for difference in averaging practices when A<I and A>I. VAISALA ______________________________________________________________________ 109 User’s Guide ______________________________________________________________________ [G] = Wind speed max/min calculation mode: 1 or 3 seconds G =1: Traditional max/min calculation is performed both for speed and direction. G =3: Gust & lull are calculated for wind speed, while direction calculation is as it is with G =1. In the output messages, gust & lull replace the wind speed max/min values (Sx, Sn), respectively. For more detailed definitions of max/min and gust & lull calculations see section Wind Measurement Principle on page 25. [U] = Speed unit: M = m/s, K = km/h, S = mph, N = knots [D] = Direction offset: -180 ... 180°, see section Wind Direction Offset on page 42. [N] = NMEA wind formatter: T = XDR (transducer syntax), W = MWV (wind speed and angle) Defines whether the wind message is sent in XDR or MWV format. [F] = Sampling rate: 1, 2, or 4 Hz Defines how frequently the wind is measured. Lower sampling rate reduces the power consumption, but it also weakens the measurement representativeness. <cr><lf> = Response terminator NOTE When using MWV wind messages in NMEA 0183, one of the [R] field's bits 1-6 must be 1. NOTE For representative wind values, use long enough averaging time in relation to sampling rate (at least four samples per averaging time). 110 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings Changing the Settings (aWU) You can change the following settings: - parameters included in the wind data message, - update interval, - averaging time, - wind speed max/min calculation mode, - speed unit, - direction offset, and - NMEA wind formatter. Make the desired setting with the following command. Select the correct value/letter for the setting fields, see Setting Fields on page 109. See the examples. Command format in ASCII and NMEA 0183: aWU,R=x,I=x,A=x,G=x,U=x,D=x,N=x,F=x<cr><lf> Command format in SDI-12: aXWU, R=x,I=x,A=x,G=x,U=x,D=x,N=x,F=x! where NOTE R, I, A, G, U, = D, N, F The wind sensor setting fields, see Setting Fields on page 109. x = Value for the setting <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 If averaging time [A] is greater than update interval [I], it shall be a whole multiple of the update interval and at maximum 12 times greater. Example: If I = 5 s, Amax = 60 s. VAISALA ______________________________________________________________________ 111 User’s Guide ______________________________________________________________________ Examples (ASCII and NMEA 0183, device address 0): You need a 20-second averaging time for wind speed and direction both in wind data and composite data message in every 60 seconds. Wind speed shall be in knots and wind direction offset +10°. Changing the measurement interval to 60 seconds: 0WU,I=60<cr><lf> 0WU,I=60<cr><lf> NOTE 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 unit to knots, and direction offset to +10°: 0WU,A=20,U=N,D=10<cr><lf> 0WU,A=20,U=N,D=10<cr><lf> 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 wind message response after the change above: 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. 112 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings Pressure, Temperature, and Humidity Sensors Checking the Settings (aTU) With this command you can check the current pressure, temperature and humidity sensor settings. Command format in ASCII and NMEA 0183: aTU<cr><lf> Command format in SDI-12: aXTU! where a = Device address TU = Pressure, temperature and humidity sensor settings command in ASCII and NMEA 0183 XTU = Pressure, temperature and humidity 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: 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 ______________________________________________________________________ 113 User’s Guide ______________________________________________________________________ Setting Fields [R] The bits 1-8 determine the parameters included in the message obtained with the following commands: -ASCII: aR2 and ar2 -NMEA 0183: $--WIQ,XDR*hh -SDI-12: aM2, aMC2, aC, and aCC2 -SDI-12 continuous: aR2 and aRC2 = 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. 1st bit (most left) 2nd bit 3rd bit 4th bit 5th bit 6th bit 7th bit 8th bit & The bits 9-16 determine the 9th bit PTU parameters included in 10th bit the composite data message 11th bit obtained with the following 12th bit commands: 13th bit -ASCII: aR0 and ar0 14th bit -NMEA 0183: aR0, ar0 -SDI-12: aM, aMC, aC, and aCC 15th bit -SDI-12 continuous: aR and 16th bit aRC Pa Air pressure Ta Air temperature Tp Internal temperature1 Ua Air humidity spare spare spare spare delimiter Pa Air pressure Ta Air temperature Tp Internal temperature1 Ua Air humidity spare spare spare spare 1. Tp temperature value is used in pressure calculation, it does not express the air temperature. [I] = Update interval: 1 ... 3600 seconds [P] = Pressure unit: H = hPa, P = Pascal, B = bar, M = mmHg, I = inHg [T] = Temperature unit: C = Celsius, F = Fahrenheit <cr><lf> = Response terminator 114 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings Changing the Settings (aTU) You can change the following settings: - parameters included in the data message, - update interval, - pressure unit, and - temperature unit. Make the desired setting with the following command. Select the correct value/letter for the setting fields, see Setting Fields on page 114. See the examples. Command format in ASCII and NMEA 0183: aTU,R=x,I=x,P=x,T=x<cr><lf> Command format in SDI-12: aXTU,R=x,I=x,P=x,T=x! where R, I, P, T = x The pressure, temperature and humidity sensor setting fields, see Setting Fields on page 114. Value for the setting <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 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 ______________________________________________________________________ 115 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. Precipitation Sensor Checking the Settings (aRU) With this command you can check the current precipitation sensor settings. Command format in ASCII and NMEA 0183: aRU<cr><lf> Command format in SDI-12: aXRU! where a = Device address RU = Precipitation sensor settings command in ASCII and NMEA 0183 XRU = Precipitation 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: aRU,R=[R],I=[I],U=[U],S=[S],M=[M],Z=[Z],X=[X],Y=[Y]<cr> <lf> 116 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings The response in SDI-12: aXRU,R=[R],I=[I],U=[U],S=[S],M=[M],Z=[Z],X=[X],Y=[Y]<cr> <lf> where [R][I][U][S][M][Z][X][Y] 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,X=100, Y=100<cr><lf> Example (SDI-12, device address 0): 0RU!0RU,R=11111100&10000000,I=60,U=M,S=M,M=R, Z=M,X=100,Y=100<cr><lf> VAISALA ______________________________________________________________________ 117 User’s Guide ______________________________________________________________________ Setting Fields [R] = 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 parameters included in the messages obtained with the following commands: -ASCII: aR3 and ar3 -NMEA 0183: $--WIQ,XDR*hh -SDI-12: aM3, aMC3, aC3, aCC3 -SDI-12 continuous: aR3 and ar3 The bits 9-16 determine the precipitation parameters included in the composite data messages obtained with the following commands: -ASCII: aR0 and ar0 -NMEA 0183: aR0, ar0 -SDI-12: aM, aMC, aC, aCC -SDI-12 continuous: aR and aRC 1st bit (most left) 2nd bit 3rd bit 4th bit 5th bit 6th bit 7th bit 8th bit & 9th bit 10th bit 11th bit 12th bit 13th bit 14th bit 15th bit 16th bit (most right) Rc Rain amount Rd Rain duration Ri Rain intensity Hc Hail amount Hd Hail duration Hi Hail intensity Rp Rain peak Hp Hail peak delimiter Rc Rain amount Rd Rain duration Ri Rain intensity Hc Hail amount Hd Hail duration Hi Hail intensity Rp Rain peak Hp Hail peak [I] = Update interval: 1 ... 3600 seconds. This interval is valid only if the [M] field is = T [U] = Precipitation units: M = metric (accumulated rainfall in mm, Rain duration in s, Rain intensity in mm/h) I = imperial (the corresponding parameters in units in, s, in/h) 118 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings [S] = Hail units: M = metric (accumulated hailfall in hits/cm2, Hail event duration in s, Hail intensity in hits/cm2h) I = imperial (the corresponding parameters in units hits/in2, s, hits/in2h), H = hits (hits, s, hits/h) Changing the unit resets the precipitation counter. [M] = Autosend mode: R = precipitation on/off, C = tipping bucket, T = time based R = precipitation on/off: The transmitter sends a precipitation message 10 seconds after the first recognition of precipitation. Rain duration Rd increases in 10 s steps. Precipitation has ended when Ri = 0. This mode is used for indication of the start and the end of the precipitation. C = tipping bucket: The transmitter sends a precipitation message at each unit increment (0.1 mm/0.01 in). This simulates conventional tipping bucket method. T = time based: Transmitter sends a precipitation message in the intervals defined in the [I] field. However, in polled protocols the autosend mode tipping bucket should not be used as in it the resolution of the output is decreased (quantized to tipping bucket tips). [Z] = Counter reset: M = manual, A = automatic, L=limit Y = immediate M = manual reset mode: The counter is reset with aXZRU command only, see Precipitation Counter Reset (aXZRU) on page 67. A = automatic reset mode: The counts are reset after each precipitation message whether in automatic mode or when polled. L = overflow reset mode. The rain counter or hail counter is reset, when it reaches the predefined limit. The overflow limits (x, y) are defined with the commands aRU,X=x for rain counter and aRU,Y=y for hail counter. Y = immediate reset: The counts are reset immediately after receiving the command. VAISALA ______________________________________________________________________ 119 User’s Guide ______________________________________________________________________ [X] = Rain accumulation limit : 100...65535. Sets the rain accumulation counter resetting limit. When the value exceeds the limit, the counter is reset to zero. If the precipitation unit aRU,U=x is metric, the limit corresponds the range between 1.00 …655.35 mm. If the precipitation unit is imperial, the equivalent range varies between 0.100 … 65.535 in. To enable this feature, set the counter reset to aRU,Z=L (overflow reset mode). [Y] = Hail accumulation limit : 100...65535. Sets the hail accumulation counter resetting limit. When the value exceeds the limit, the counter is reset to zero. If the hail unit aRU,S=x is metric, the limit corresponds the range between 10.0 …6553.5 hits/ cm2. If the unit is imperial, the equivalent range varies between 100 … 65535 hits/in2. If the unit is hits, the limit matches directly to the amount of hits: 100…65535 hits. To enable this feature, set the counter reset to aRU,Z=L (overflow reset mode). <cr><lf> = Response terminator 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 field [Z] defines how the counters are reset. Use "L" to enable the rain overflow reset mode. Now the rain accumulation limit feature (X and Y) becomes particularly useful for systems using an analog interface adapter. Thus, the dataloggers have no serial interface that would enable them to reset the rain counters. 120 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings Changing the Settings (aRU) You can change the following settings: - parameters included in the precipitation data message, - update interval in the time based autosend mode, - precipitation units, - hail units, - autosend mode, - counter reset, - rain accumulation limit and - hail accumulation limit. Make the desired setting with the following command. Select the correct value/letter for the setting fields, see Setting Fields on page 118. See the examples. Command format in ASCII and NMEA 0183: aRU,R=x,I=x, U=x,S=x,M=x,Z=x, X=x, Y=x<cr><lf> Command format in SDI-12: aXRU,R=x,I=x,U=x,S=x,M=x,Z=x, X=x,Y=x! where R, I, U, S, = M, Z, X, Y The precipitation sensor setting fields, see Setting Fields on page 118. x = Input value for the setting <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 Examples (ASCII and NMEA 0183): Changing the precipitation units to imperial: 0RU,U=I<cr><lf> 0RU,U=I<cr><lf> VAISALA ______________________________________________________________________ 121 User’s Guide ______________________________________________________________________ Changing the autosend mode to the tipping bucket mode: 0RU,M=C<cr><lf> 0RU,M=C<cr><lf> Making the Rain amount Rc and Rain intensity Ri available both in the precipitation message and composite data message: 0RU,R=1010000010100000<cr><lf> 0RU,R=10100000&10100000<cr><lf> 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. Supervisor Message Checking the Settings (aSU) 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 a = Device address SU = Supervisor settings command in ASCII and NMEA 0183 XSU = Supervisor settings command in SDI-12 122 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 The response in ASCII and NMEA 0183: aSU,R=[R],I=[I],S=[S],H=[Y]<cr><lf> The response in SDI-12: aXSU,R=[R],I=[I],S=[S],H=[Y]<cr><lf> Setting Fields [R] The bits 1-8 determine the parameters included in the message obtained with the following commands: -ASCII: aR5 and ar5 -NMEA 0183: $--WIQ,XDR*hh -SDI-12: aM5, aMC5, aC5, and aCC5 -SDI-12 continuous: aR5 and aRC5 = Parameter selection: This field consists of 16 bits defining the supervisor parameters included in the data messages. The bit value 0 disables and the bit value 1 enables the parameter. 1st bit (most left) 2nd bit 3rd bit 4th bit 5th bit 6th bit 7th bit 8th bit & The bits 9-16 determine the 9th bit supervisor parameters 10th bit included in the composite data 11th bit message obtained with the 12th bit following commands: 13th bit -ASCII: aR0 and ar0 14th bit -NMEA 0183: aR0, ar0 -SDI-12: aM, aMC, aC, and aCC 15th bit -SDI-12 continuous: aR and 16th bit (most right) aRC Th Heating temperature Vh Heating voltage Vs Supply voltage Vr 3.5 V reference voltage Id Information field spare spare spare delimiter Th Heating temperature Vh Heating voltage Vs Supply voltage Vr 3.5 V reference voltage Id Information field spare spare spare VAISALA ______________________________________________________________________ 123 User’s Guide ______________________________________________________________________ [I] = Update interval: 1 ... 3600 seconds. When the heating is enabled the update interval is forced to 15 seconds. [S] = Error messaging: Y = enabled, N = disabled [H] = 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 29. Heating disabled: Heating is off in all conditions. <cr><lf> = Response terminator 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 (aSU) You can change the following settings: - parameters included in the supervisor data message, - update interval, - error messaging on/off, and - heating control. Make the desired setting with the following command. Select the correct value/letter for the setting fields, see Setting Fields on page 123. See the examples. 124 __________________________________________________________________M210906EN-A Chapter 8 ____________________________________________ Sensor and Data Message Settings Command format in ASCII and NMEA 0183: aSU,R=x,I=x,S=x,H=x<cr><lf> Command format in SDI-12; aXSU,R=x,I=x,S=x,H=x! where R, I, S, H = The supervisor setting fields, see Setting Fields on page 123. x = Value for the setting <cr><lf> = Command terminator in ASCII and NMEA 0183 ! = Command terminator in SDI-12 Example (ASCII and NMEA 0183, device address 0): Disabling the heating and error messaging: 0SU,S=N,H=N<cr><lf> 0SU,S=N,H=N<cr><lf> Example (SDI-12, device address 0): Changing the update interval to 10 seconds: 0XSU,I=10!0<cr><lf> In SDI-12 mode a separate enquiry (0XSU!) must be given to check the data content. Composite Data Message (aR0) The parameters to be included in the composite data message aR0 can be defined in the parameter selection fields of each parameter (aWU,R, aTU,R, aRU,R, and aSU,R). See parameter tables of each sensor in the previous sections. See the following examples. NOTE When changing the bits 9-16 of the parameter selection of any sensor, the command can be shortened by replacing the bits 1-8 with a single '&' character, see the examples. VAISALA ______________________________________________________________________ 125 User’s Guide ______________________________________________________________________ Example (ASCII and NMEA 0183, device address 0): 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> Replace the maximum wind direction (Dx) and speed (Sx) with average wind direction (Dm) and average wind speed (Sm): 0WU,R=&01001000<cr><lf> 0WU,R=11110000&01001000<cr><lf> Remove the heating voltage (Vh) and temperature (Th) data from the composite data message, and include the information field (Id): 0SU,R=&00001000<cr><lf> 0SU,R=11110000&00001000<cr><lf> Remove the accumulated rainfall (Rc) from the composite data message: 0RU,R=&00000000<cr><lf> 0RU,R=11111100&00000000<cr><lf> The final composite data message query and response in ASCII: 0R0<cr><lf> 0R0,Dm=009D,Sm=0.2M,Ta=23.3C,Ua=37.5P, Pa=996.8H,Id=HEL___<cr><lf> 126 __________________________________________________________________M210906EN-A Chapter 9 ______________________________________________________________ Maintenance CHAPTER 9 MAINTENANCE This chapter contains instructions for the basic maintenance of Weather Transmitter WXT520 and contact information for Vaisala Service Centers. Cleaning To ensure the accuracy of measurement results, Weather Transmitter WXT520 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. CAUTION Be extremely careful when cleaning the wind sensors. The sensors should not be rubbed nor twisted. VAISALA ______________________________________________________________________ 127 User’s Guide ______________________________________________________________________ Replacing the PTU Module 1. Turn the power off. Loosen the three fixing screws at the bottom assembly of the WXT520. 2. Turn out the top of the transmitter. 3. Release the small white latch (see section A in Figure 26 on page 128) and remove the PTU module. 4. Remove the vacuum bag protecting the PTU module. Connect the new PTU module. Avoid touching the white filter cap with your hands when handling the PTU module. 5. Turn the top back in. Make sure the flat cable does not get stuck or squeezed between the top and the funnel for the flat cable. 6. Tighten the three fixing screws that fasten the top and the bottom. To make sure that the radiation shield stays straight, do not tighten the screws all the way in one go. Do not overtighten. 0602-013 Figure 26 Replacing the PTU Module 128 __________________________________________________________________M210906EN-A Chapter 9 ______________________________________________________________ Maintenance Factory Calibration and Repair Service Send the device to Vaisala Instruments Service Centers for calibration and adjustment, see contact information below. Vaisala Service Centers NORTH AMERICAN SERVICE CENTER Vaisala Inc., 10-D Gill Street, Woburn, MA 01801-1068, USA. Phone: +1 781 933 4500, Fax: +1 781 933 8029 E-mail: [email protected] EUROPEAN SERVICE CENTER Vaisala Instruments Service, Vanha Nurmijärventie 21 FIN-01670 Vantaa, FINLAND. Phone: +358 9 8949 2658, Fax: +358 9 8949 2295 E-mail: [email protected] TOKYO SERVICE CENTER Vaisala KK, 42 Kagurazaka 6-Chome, Shinjuku-Ku, Tokyo 162-0825, JAPAN. Phone: +81 3 3266 9617, Fax: +81 3 3266 9655 E-mail: [email protected] 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: [email protected] www.vaisala.com VAISALA ______________________________________________________________________ 129 User’s Guide ______________________________________________________________________ 130 __________________________________________________________________M210906EN-A Chapter 10 __________________________________________________________ Troubleshooting CHAPTER 10 TROUBLESHOOTING This chapter describes common problems, their probable causes and remedies, and includes contact information for technical support. Table 9 Data Validation Problem Possible causes Action(s) Wind measurement failure. Both the speed and direction units are replaced by a # sign or the data values are irrelevant. Blockage (trash, leaves, branches, bird, snow, ice) between the wind transducers. Incorrect <cr><lf> settings in the terminal program. Remove the blockage, and check that the wind transducers are not damaged. If the blockage is ice or snow, it will melt after some time if heating is enabled. Time for clearance depends on the severity of the weather event. If birds are causing the blockage, consider using the bird spike kit. Pressure, humidity or temperature measurement failure. The unit is replaced by a # sign or the data values are irrelevant. The PTU module may not be properly connected. There may be water in the PTU module. In ASCII and NMEA protocols both <cr> and <lf> are required after each command. Check that your terminal program sends both when pressing enter. Note: The direction unit is # for the wind speeds less than 0.05 m/s. Ensure the proper connection of the PTU module. Remove and dry the module. VAISALA ______________________________________________________________________ 131 User’s Guide ______________________________________________________________________ Table 10 Communication Problems Problem Possible causes Action(s) No response to any commands. Wrong wiring or operation voltage not connected. Baud rate/start bits/parity/stop bit settings do not match between the device and the host. Check the wiring and operation voltage, see Chapter 5, Wiring and Power Management, on page 43. Connect the service cable, use the communication settings 19200,8 N,1. Check the serial port settings of the device with Configuration Tool or with terminal program. Use command aXU! (SDI-12) or aXU<cr><lf> (ASCII/NMEA). Change the values if needed. A software/ hardware reset is needed to validate the changes. When you have no service cable, try typing address query commands ?! and ?<cr><lf> with different serial settings in terminal program. When the communication parameters match, the device responds with its address. The settings can now be changed using aXU! (SDI-12) or aXU<cr><lf> (ASCII/ NMEA) commands. A software/ hardware reset is needed to validate the changes. In ASCII and NMEA protocols both <cr> and <lf> are required after each command. Check that your terminal program sends both when pressing enter. Request the device address with ?! command and then retype the command now with the correct address. Check the data query commands from Chapter 7, Getting the Data Messages, on page 65. Enable the error messaging using the Vaisala Configuration Tool or any terminal by setting aSU,S=Y, then try the command again. Incorrect <cr><lf> settings in the terminal program. Connection works but data messages not available. Wrong device address in a SDI12 command or a mistyped SDI12 command (in SDI-12 a mistyped command is in no way responded). A command mistyped in ASCII/ NMEA mode while error messaging/text messages is disabled (aSU,S=N). 132 __________________________________________________________________M210906EN-A Chapter 10 __________________________________________________________ Troubleshooting Table 10 Communication Problems (Continued) Problem Possible causes Action(s) Data messages are not in expected format. The communication protocol may not be the one you want. Some parameters are missing from the data messages. The formatting of the data messages is not what you expect. An error message as a response to a command. WXT520 keeps sending the message "TX Sync/address error". See section Error Messaging/ Text Messages on page 133. The polling address and WXT520 address do not match. The WXT520 is on an RS-485 bus with other polled devices and Error Messages are enabled. Check the communication protocol of the device by using the Vaisala Configuration Tool or any terminal with command aXU,M! (SDI-12) aXU,M<cr><lf> (ASCII/NMEA) and change it if needed. See Chapter 6, Connection Options, on page 55. Format the data messages of the concern by using the Vaisala Configuration Tool or any terminal program. See Chapter 8, Sensor and Data Message Settings, on page 107. See section Error Messaging/ Text Messages on page 133. Set correct address either for the WXT520 or to the polling request. Disable the Error Messages with the command aSU,S=N <crlf>. Self-Diagnostics Error Messaging/Text Messages WXT520 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 (aSU) on page 124. Examples: 0R1!0TX,Unable to measure error<cr><lf> (request of wind data while all the wind parameters were disabled from the wind message) 1XU!0TX,Sync/address error<cr><lf> (wrong device address. Ask the correct address with ? or ?! command. 0XP!0TX,Unknown cmd error<cr><lf> VAISALA ______________________________________________________________________ 133 User’s Guide ______________________________________________________________________ 0xUabc!0TX,Use chksum CCb<cr><lf> (wrong checksum applied to the 0xU command) Table 11 Text message Text Message identifier (in NMEA 0183 v3.0 protocol only) 01 Error Messaging/Text Messages Table Interpretation and action Unable to measure error The requested parameters are not activated in the message, see Chapter 8, Sensor and Data Message Settings, on page 107, and check the parameter selection fields. Sync/address error The device address in the beginning of the command is invalid. Ask the device address with the ?! (SDI-12) or ?<cr><lf> (ASCII and NMEA) command and retype the command with the correct address. Unknown cmd error The command is not supported, use the correct command format, see Chapter 7, Getting the Data Messages, on page 65. Profile reset Checksum error in configuration settings during powerup. Factory settings used instead. Factory reset Checksum error in calibration settings during power-up. Factory settings used instead. Version reset New software version in use. Start-up Software reset. Program starts from the beginning. Use chksum xxx Given checksum not correct for the command. Use the proposed checksum. Measurement reset The ongoing measurement of all the sensors interrupted and started from the beginning. Rain reset The precipitation sensor counter reset. Inty reset Precipitation sensor intensity counter reset. 02 03 04 05 06 07 08 09 10 11 See also Chapter 10, Troubleshooting, on page 131. In case of constant error, please contact Vaisala Service Center, see Vaisala Service Centers on page 129. NOTE When WXT520 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>. 134 __________________________________________________________________M210906EN-A Chapter 10 __________________________________________________________ Troubleshooting Rain and Wind Sensor Heating Control The supervisor message aSU (see Supervisor Message on page 122) shows you continuously monitored information about rain and wind sensor heating (heating temperature Th and heating voltage Vh). The heating temperature should stay above 0 °C when the heating is on (except in extremely cold conditions where the heating power is not sufficient). The heating voltage Vh should correspond to the heating voltage supplied. If there is a remarkable deviation, check the wiring. Note that wire gauge should be large enough to avoid remarkable voltage drop in the cable. NOTE In case AC or full-wave rectified AC is used for the heating, the Vh measurement behaves as follows: While heating is off, Vh indicates the positive peak value (Vp) of the heating voltage waveform. While heating is on, Vh indicates: - 0.35 x Vp in case of AC voltage - 0.70 x Vp in case of full-wave rectified AC voltage Operating Voltage Control The supervisor message aSU (see Supervisor Message on page 122) shows you continuously monitored supply voltage level (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 [email protected] Fax +358 9 8949 2790 VAISALA ______________________________________________________________________ 135 User’s Guide ______________________________________________________________________ 136 __________________________________________________________________M210906EN-A Chapter 11 ____________________________________________________ Technical Specifications CHAPTER 11 TECHNICAL SPECIFICATIONS This chapter provides the technical data of Weather Transmitter WXT520. Performance Table 12 Barometric Pressure Property Description/Value Range Accuracy 600 ... 1100 hPa ±0.5 hPa at 0 ... +30 °C (+32 ... +86 °F) ±1 hPa at -52 ... +60 °C (-60 ... +140 °F) 0.1 hPa, 10 Pa, 0.001 bar, 0.1 mmHg, 0.01 inHg hPa, Pa, bar, mmHg, inHg Output resolution Units available Table 13 Property Air Temperature Description/Value Range -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 ______________________________________________________________________ 137 User’s Guide ______________________________________________________________________ °C 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 °C -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7 -80 -60 -40 -20 0 20 40 0505-209 Figure 27 Accuracy Over Temperature Range Table 14 Wind Property Wind speed range response time available variables accuracy output resolution units available Wind direction azimuth response time available variables accuracy output resolution Measurement frame averaging time update interval 60 80 Description/Value 0 ... 60 m/s 0.25 s average, maximum, and minimum ±0.3 m/s or ±3 % whichever is greater for the measurement range of 0 ... 35 m/s ±5 % for the measurement range of 36 ... 60 m/s 0.1 m/s (km/h, mph, knots) m/s, km/h, mph, knots 0 ... 360° 0.25 s average, maximum, and minimum ±3.0° 1° 1 ... 3600 s (= 60 min), at 1 s steps, on the basis of samples taken at 4, 2 or 1 Hz rate (configurable) 1 ... 3600 s (= 60 min), at 1 s steps 138 __________________________________________________________________M210906EN-A Chapter 11 ____________________________________________________ Technical Specifications Table 15 Relative Humidity Property Description/Value Range Accuracy 0 ... 100 %RH ±3 %RH at 0 ... 90 %RH ±5 %RH at 90 ... 100 %RH 0.1 %RH 1 ... 3600 s (= 60 min), at one second steps Output resolution PTU Measuring interval Table 16 Precipitation Property Description/Value Rainfall cumulative accumulation after the latest auto or manual reset collecting area 60 cm2 0.01 mm (0.001 in) output resolution field accuracy for daily accumulation units available Rain duration output resolution Rain intensity range units available Hail better than 5 %1, weather dependent mm, in counting each 10-second increment whenever droplet detected 10 s running one minute average in 10-second steps 0 ... 200 mm/h (broader range with reduced accuracy) mm/h, in/h cumulative amount of hits against collecting surface output resolution 0.1 hit/cm2, 1 hit/in2, 1 hit units available hits/cm2, hits/in2, hits counting each 10-second increment whenever hailstone detected 10 s one-minute running average in 10-second steps Hail duration output resolution Hail intensity output resolution 0.1 hit/cm2h, 1 hit/in2h, 1 hit/h units available hits/cm2h, hits/in2h, hits/h 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 ______________________________________________________________________ 139 User’s Guide ______________________________________________________________________ Inputs and Outputs Table 17 Inputs and Outputs Property Description/Value Operating voltage 5 ... 32 VDC1 Average current consumption minimum typical maximum Heating voltage typical ranges 0.1 mA @ 12 VDC (SDI-12 standby) 3 mA @ 12 VDC (with default measuring intervals) 14 mA @ 5 VDC (with constant measurement of all parameters) Options: DC, AC, full-wave rectified AC 12 VDC ± 20 %, 1.1 A max 24 VDC ± 20 %, 0.6 A max 68 Vp-p ± 20 % (AC), 0.6 Arms max 34 Vp ± 20 % (f/w rect. AC), 0.6 Arms max absolute max 32 VDC 84 Vp-p (AC) 42 Vp (f/w rect. AC) Digital outputs Communication protocols SDI-12, RS-232, RS-485, RS-422 SDI-12 v1.3, ASCII automatic & polled, NMEA 0183 v3.0 with query option 1. Below 5.3 V the measurement performance for high wind speeds may be degraded. 140 __________________________________________________________________M210906EN-A Chapter 11 ____________________________________________________ Technical Specifications Operating Conditions Table 18 Operating Conditions Property Description/Value Housing protection class IP65 (without mounting kit) IP66 (with mounting kit attached) Temperature Operation Storage Relative humidity Pressure Wind1 -52 ... +60 °C (-60 ... +140 °F) -60 ... +70 °C (-76 ... +158 °F) 0 ... 100 %RH 600 ... 1100 hPa 0 ... 60 m/s 1. Due to the measurement frequency used in the sonic transducers, RF interference in the 200-400 kHz range can disturb wind measurement. Any temporary element or object (snow, ice, bird etc.) blocking the measurement path between the ultrasonic transducer heads may affect the wind measurement accuracy or even invalidate the output data. Table 19 Electromagnetic Compatibility Applicable Standard Description Level tested CISPR 22 CISPR 22 Performance1 Radiated emissions 30 Hz - 2 GHz Conducted emissions 150 Hz - 30 MHz DC IEC 61000-4-2 Electrostatic discharge 6 kV con / 8 kV air 10 V/m IEC 61000-4-3 RF field immunity2 Class B Class B IEC 61000-4-4 Electric fast transient IEC 61000-4-5 Surge IEC 61000-4-6 Conducted RF immunity B B A 2 kV 2 kV 3 Vemf B A 1. A = Normal performance B = Temporary degradation (self-recoverable) C = Temporary degradation (operator intervention needed) D = not recoverable 2. Within frequency range 600 ... 700 MHz immunity for PTU is 8 V/m VAISALA ______________________________________________________________________ 141 User’s Guide ______________________________________________________________________ Materials Table 20 Materials Property Description/Value Radiation shield, top, and bottom parts Precipitation sensor plate Weight Polycarbonate + 20 % glass fibre Stainless steel (AISI 316) 650 g (1.43 lbs.) General Table 21 General Property Description/Value Self-diagnostic Separate supervisor message, unit/status fields to validate measurement stability Automatic, <5 seconds from power on to the first valid output Start-up 142 __________________________________________________________________M210906EN-A Chapter 11 ____________________________________________________ Technical Specifications Options and Accessories Table 22 Options and Accessories Description Order code Service Pack 2: Vaisala Configuration Tool software and USB service cable USB service cable adapter for WXT510/ WMT50 USB RS-232/RS-485 cable M12 female 2-meter cable with 8-pin M12 female connector 10-meter cable with 8-pin M12 female connector 10-meter extension cable with 8-pin M12 female and male connectors 40-meter cable, open ends Bushing and Grounding kit WXT520 Bottom assembly (with M12 connector and interface card) Mounting kit WXT520 PTU module WXT520 Radiation shield (5 pcs) Surge Protector for transmitter Surge Protector for USB and PC Bird Spike Kit 220614 221523 220782 222287 222288 215952 217020 222109 WXTBOTTOMSP 212792 WXTPTUSP 218817SP WSP150 WSP152 212793 VAISALA ______________________________________________________________________ 143 User’s Guide ______________________________________________________________________ Dimensions (mm/inch) 0803-040 Figure 28 WXT520 Dimensions, Side View 144 __________________________________________________________________M210906EN-A Chapter 11 ____________________________________________________ Technical Specifications 0805-013 Figure 29 WXT520 Dimensions, Top and Bottom View VAISALA ______________________________________________________________________ 145 User’s Guide ______________________________________________________________________ 0505-211 Figure 30 Mounting Kit Dimensions The following numbers refer to Figure 23 on page 120: 1 = Mounting kit with adapter sleeve for ø26.7 mm mast tube 2 = Mounting kit without adapter sleeve for ø30 mm mast tube 146 __________________________________________________________________M210906EN-A Appendix A ______________________________________________________________ Networking APPENDIX A NETWORKING Connecting Several WXT520s on the Same Bus Connecting several WXT520s on the same bus is possible in two ways: 1. Using SDI-12 serial interface and communication protocol, and 2. Using RS-485 serial interface and one of the following communication protocols: ASCII or NMEA 0183 v3.0. SDI-12 Serial Interface Wiring 1. Make the SDI-12 wiring in WXT520 as described in Chapter 5, Wiring and Power Management, on page 43. Remember to combine the two "Data in/out"wires of each WXT520 either in the internal screw terminal inside or outside the transmitter. 2. In the data logger end, combine the "GND for data" wires of each WXT520 to the logger "GND for data" wire. Connect the "Data in/ out" wires of each WXT520 to the logger "Data" wire. VAISALA ______________________________________________________________________ 147 User’s Guide ______________________________________________________________________ Communication Protocol Set the communication protocol SDI-12 v 1.3 (aXU,C=1,M=S) or SDI12 v1.3 continuous (aXU,C=1,M=R). WXT520s on the bus shall be assigned with different addresses (for example: aXU,A=0,1,2, ... ). Thereafter WXT520s on the bus do not respond to the commands not assigned to them nor to the data messages sent by the other WXT520s. Example (A bus with three WXT520s): WXT520 #1 communication settings: 0XXU,A=0,M=S,C=1,B=1200,D=7,P=E,S=1, L=25 WXT520 #2 communication settings: 1XXU,A=1,M=S,C=1,B=1200,D=7,P=E,S=1, L=25 WXT520 #3 communication settings: 2XXU,A=2,M=S,C=1,B=1200,D=7,P=E,S=1, L=25 If simultaneous measurements of the different units are needed, Start concurrent measurement commands aC and aCC should be use for all devices. If the measurements are to be performed consecutively for only one unit at time, in addition to these also Start measurement commands aM and aMC can be used. Start continuous measurement commands aR1, aR2, aR3, aR5, aR, aRC1, aRC2, aRC3, aRC5 and aRC available only in SDI-12 continuous protocol (aXU,M=R) can be used eiher for simultaneous measurements of the units or consecutive measurements for one unit at time. See also SDI-12 Protocol on page 80. RS-485 Serial Interface Wiring 1. Make the RS-485 wiring of WXT520 as described in Chapter 5, Wiring and Power Management, on page 43. 2. In the data logger end, combine the "Data +" wires of each WXT520 to the logger "Data +" wire. Connect the "Data-" wires of each WXT520 to the logger "Data -" wire. 148 __________________________________________________________________M210906EN-A Appendix A ______________________________________________________________ Networking Communication Protocol Set the communication protocol to ASCII polled (with or without CRC) or NMEA query. When using NMEA query, the wind message should be set to XDR (aWU,N=T). NOTE 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 WXT520 on the bus in order to prevent the units responding to the commands not assigned to them. ASCII, Polled WXT520s on the bus shall be assigned with different addresses. (for example: aXU,A=0,1,2, ... ). Example (a bus with three WXT520s): WXT520 #1 communication settings: 0XU,A=0,M=P,C=3,I=0,B=19200,D=8,P=N,S=1,L=25 WXT520 #2 communication settings: 1XU,A=1,M=P,C=3,I=0,B=19200,D=8,P=N,S=1,L=25 WXT520 #3 communication settings: 2XU,A=2,M=P,C=3,I=0,B=19200,D=8,P=N,S=1,L=25 Example (composite data message queries to the sensors 1 and 3 are assigned as follows): 0R0<cr><lf> 1R0<cr><lf> 2R0<cr><lf> VAISALA ______________________________________________________________________ 149 User’s Guide ______________________________________________________________________ NMEA 0183 v3.0, Query The NMEA 0183 query messages do not contain device address information. Individual query commands can thus not be directed to different transmitters. Instead, a specific Time Slot method can be used for receiving data from several transmitters on the bus, just with a single query command. To generate different time slots, each WXT520 is given an individual delay for its query response, by using the RS-485 line delay parameter aXU,L. This parameter defines the time (in milliseconds) between the last character of the query and the first character of the response from WXT520. Example (a bus with three WXT520s): WXT520 #1 communication settings: 0XU,A=0,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=25 WXT520 #2 communication settings: 0XU,A=0,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=1000 WXT520 #3 communication settings: 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, WXT520 #1 responds after 25 ms, WXT520 #2 after 1000 ms and WXT520 #3 responds after 2000 ms. The sufficient delays depend on the maximum number of characters in the response messages and the baud rate. Note that all the transmitters are assigned with the same address. Hence the data logger, after sending the query, shall sort out the response messages on the basis of the individual response times. To gain even more addressability transducer ID information provided in the XDR response messages can also be used. If WXT520 address is set to 0 (aXU,A=0) and all parameters are chosen except Rain peak intensity and Hail peak intensity in the precipitation message, the response to the XDR-query $--WIQ,XDR*2D<cr><lf> will be like: $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> 150 __________________________________________________________________M210906EN-A Appendix A ______________________________________________________________ Networking $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> $WIXDR,C,25.8,C,2,U,10.7,N,0,U,10.9,V,1,U,3.360,V,2*7D<cr><lf> For the transducer IDs, see NMEA 0183 V3.0 Protocol on page 92. The maximum transducer ID is three when WXT520 address is 0. Hence, assigning address 4 for the second and address 8 for the third WXT520 on the bus the following responses to the XDR-query $-WIQ,XDR*2D<cr><lf> will be obtained from these transmitters (same message parameter configuration): The second transmitter (address 4): $WIXDR,A,330,D,4,A,331,D,5,A,333,D,6,S,0.1,M,4,S,0.1,M,5,S,0.2, M,6*55<cr><lf> $WIXDR,C,23.5,C,4,C,24.3,C,4,H,49.3,P,4,P,1010.1,H, 3*59<cr><lf> $WIXDR,V,0.000,I,4,Z,0,s,4,R,0.00,I,4,V,0.0,M,5,Z,0,s,5,R,0.0,M, 5*67<cr><lf> $WIXDR,C,25.8,C,6,U,10.6,N,4,U,10.9,V,5,U,3.362,V,6*78<cr><lf> The third transmitter (address 8): $WIXDR,A,341,D,8,A,347,D,9,A,357,D,10,S,0.1,M,8,S,0.2,M,9,S,0.2, M,10*53<cr><lf> $WIXDR,C,23.5,C,8,C,24.3,C,9,H,49.3,P,8,P,1010.1,H, 8*5F<cr><lf> $WIXDR,V,0.000,I,8,Z,0,s,8,R,0.00,I,8,V,0.0,M,9,Z,0,s,9,R,0.0,M, 9*61<cr><lf> $WIXDR,C,25.8,C,10,U,10.6,N,8,U,10.9,V,9,U,3.360,V, 10*7C<cr><lf> Now the response messages of all three transmitters can be recognized and parsed by the data logger. VAISALA ______________________________________________________________________ 151 User’s Guide ______________________________________________________________________ NOTE WXT520 address may consist of letter characters but the transducer 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: WXT520 address = A => transducer ID = 10, B => 11, a => 36, b => 37 etc. NMEA 0183 v3.0 Query with ASCII Query Commands You can use ASCII query commands aR1, aR2, aR3, aR5, aR, aR0 and their CRC-versions ar1, ar2, ar3, ar5, ar and ar0 also in NMEA 0183 protocol. The responses to these commands will be in standard NMEA 0183 format. and the transmitters shall be assigned with different addresses (for example: aXU,A=0,1,2, ... ). The RS-485 line delays are not needed. Example (a bus with three WXT520s, data requests with combined data message query commands; the same message parameter configuration as in the previous example): WXT520 #1 communication settings: 0XU,A=0,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=25 WXT520 #2 communication settings: 0XU,A=1,M=Q,C=3,I=0,B=4800,D=8,P=N,S=1,L=25 WXT520 #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 WXT520 #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> $WIXDR,C,25.8,C,2,U,10.7,N,0,U,10.9,V,1,U,3.360,V,2*7D<cr><lf> 152 __________________________________________________________________M210906EN-A Appendix A ______________________________________________________________ Networking The query for WXT520 #2 and the response: 1R<cr><lf> $WIXDR,A,330,D,1,A,331,D,2,A,333,D,3,S,0.1,M,1,S,0.1,M,2,S,0.2, M,3*55<cr><lf> $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 WXT520 #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. VAISALA ______________________________________________________________________ 153 User’s Guide ______________________________________________________________________ 154 __________________________________________________________________M210906EN-A Appendix B __________________________________________________________ SDI-12 Protocol APPENDIX B SDI-12 PROTOCOL SDI-12 is a standard for interfacing data recorders with microprocessorbased sensors. The name stands for serial/digital interface at 1200 baud. More information of the complete SDI-12 standard text is available from the SDI-12 web-site in the following address: www.sdi-12.org. SDI-12 Electrical Interface The SDI-12 electrical interface uses the SDI-12 bus to transmit serial data between SDI-12 data recorders and sensors. The SDI-12 bus is the cable that connects multiple SDI-12 devices. This is a cable with three conductors: - a serial data line, - a ground line, and - a 12-volt line. The SDI-12 bus can have at least 10 sensors connected to it. The bus topology is a parallel connection, where each of the three wires of different sensors are connected in parallel. VAISALA ______________________________________________________________________ 155 User’s Guide ______________________________________________________________________ SDI-12 Communications 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 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. Other sensors on the SDI-12 bus ignore the command and return to low-power standby mode. When a data recorder tells a sensor to start its measurement procedure, the recorder does not communicate with any other sensor until the data collection from the first sensor is complete. A typical recorder/sensor measurement sequence proceeds in the following order: 1. The data recorder wakes all sensors on the SDI-12 bus with a break. 2. The recorder transmits a command to a specific, addressed sensor, instructing it to make a measurement. 3. The addressed sensor responds within 15.0 milliseconds returning the maximum time until the measurement data will be ready and the number of data values it will return. 4. If the measurement is immediately available, the recorder transmits a command to the sensor instructing it to return the measurement(s). If the measurement is not ready, the data recorder waits for the sensor to send a request to the recorder, which indicates that the data is ready. The recorder then transmits a command to get the data. 5. The sensor responds, returning one or more measurements. 156 __________________________________________________________________M210906EN-A Appendix B __________________________________________________________ SDI-12 Protocol SDI-12 Timing Figure 31 on page 157 shows a timing diagram for a SDI-12 command and its response. The tolerance for all SDI-12 timing is ±0.40 milliseconds. The only exception to this is the time between the stop bit of one character and the start bit of the next character. The maximum time for this is 1.66 milliseconds, with no tolerance. - A data recorder transmits a break by setting the data line to spacing for at least 12 milliseconds. - The sensor will not recognize a break condition for a continuous spacing time of less than 6.5 milliseconds. The sensor will always recognize a break when the line is continuously spacing for more than 12 milliseconds. - When receiving a break, a sensor must detect 8.33 milliseconds of marking on the data line before it looks for an address. - A sensor must wake up from a low-power standby mode and be capable of detecting a start bit from a valid command within 100 milliseconds after detecting a break. - After a data recorder transmits the last character of a command, it must relinquish control of the data line within 7.5 milliseconds. 0505-218 Figure 31 Timing Diagram VAISALA ______________________________________________________________________ 157 User’s Guide ______________________________________________________________________ NOTE - After receiving the break and the command, the addressed sensor sets the data line to marking at 8.33 milliseconds and then sends the response (tolerance: -0.40 milliseconds.) The start bit of the first response byte must start within 15 milliseconds after the stop bit of the last byte of the command (tolerance: +0.40 milliseconds). - After a sensor transmits the last character of a response, it must relinquish control of the data line within 7.5 milliseconds (tolerance: +0.40 milliseconds.) - No more than 1.66 milliseconds of marking are allowed between the end of the stop bit and the start bit (for example between characters) on any characters in the command or the response (no tolerance.) This permits a response to an M command to be sent within a 380-millisecond window. - Sensors must return to a low-power standby mode after receiving an invalid address or after detecting a marking state on the data line for 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. 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. 158 __________________________________________________________________M210906EN-A Appendix C ______________________________________________________ CRC-16 Computation APPENDIX C CRC-16 COMPUTATION The computation of the CRC is performed on the data response before parity is added. All operations are assumed to be on 16 bit unsigned integers. The least significant bit is on the right. Numbers preceded by 0x are in hexadecimal. All shifts shift in a zero. The algorithm is: Initialize the CRC to zero. For each character beginning with the address, up to but not including the carriage return (<cr>), do as follows: { Set the CRC equal to the exclusive OR of the character and itself for count =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 ______________________________________________________________________ 159 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>. Parity is applied to all three characters, if selected for the character frame. The CRC computation code is added to the end of the response, if the first letter of the command is sent by using lower case. NMEA 0183 v3.0 Checksum Computation The checksum is the last field in the NMEA sentence and follows the checksum delimiter character "*". It is the 8-bit exclusive OR of all characters in the sentence, including "," and "^" delimiters, between but not including the "$" or "!" and the "*" delimiters. The hexadecimal value of the most significant and least significant four bits of the result is converted to two ASCII characters (0-9,A-F) for transmission. The most significant character is transmitted first. 160 __________________________________________________________________M210906EN-A Appendix D ________________________________________ Wind Measurement Averaging Method APPENDIX D WIND MEASUREMENT AVERAGING METHOD The following three figures represent the wind measurement averaging for different selections of communication protocol, wind measurement update interval (I) and averaging time (A). Scalar averaging is used for both wind speed and direction. NOTE Grey boxes indicate that the measurement is in progress during the corresponding second. Update (= internal calculation) is always made in the end of the update interval. In the auto sending protocols (ASCII automatic (+ CRC) and NMEA automatic) outputting the data messages is synchronized to take place immediately after the update. In ASCII polled (+ CRC), NMEA query and SDI-12 continuous measurement protocols trying to request data before the update interval is completed will result in getting the data from the previous completed update interval. 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 ______________________________________________________________________ 161 User’s Guide ______________________________________________________________________ Case 1 I > A, all communication p rotocols other than SDI-12 (aXU,M=S). In this example I=5 sec and A=3 sec. A A ... ... 1 sec Case 2 I time I I < A, all communication p rotocols other than SDI-12 (aXU,M=S). In this example I=2 sec and A=5 sec. A A A A ... ... time 1 sec I I Case 3 I I Communication protocol SDI-12 (aXU,M=S). In this example A=3 sec. I does not have any function in this protocol. A A ... ... time 1 sec Data ready Issuing measurement comm and 0505-215 Figure 32 Issuing measurement command Data ready Wind Measurement Averaging Method 162 __________________________________________________________________M210906EN-A Appendix E ______________________________________________________ factory configurations APPENDIX E FACTORY CONFIGURATIONS The factory configurations are read-only settings which cannot be modified. For each settings command, the following information is shown: - the command to retrieve the settings (ends to ! character) - an example response from the WXT - a table describing the messsage contents VAISALA ______________________________________________________________________ 163 User’s Guide ______________________________________________________________________ General Unit Settings 0XF!0XF,f=11111111&11100010,o=AAC1DB1A,c=A263, i=HEL___,n=A3430012,2=2528,3=3512 <cr><lf> Table 23 General Unit Settings Field Character Field Name Description f o Factory options Order code c Calibration date i Info n Device s/n 2 3 2.5 V reference 3.5 V reference Selection of parameters Ordering identity as delivered (10 characters) Y=2003, A, B,…=2005, 2006, 1..52 = week, 1...7, weekday Factory signature (10 characters) A,B,...=2005,2006..., 1..52 = week, 1...7 = weekday , 1...9999 = serial number 2500mV (default) 3500mV (default) Wind Configuration Settings 0WF!0WF,g=A,l=N,t=A,0=273.00,1=273.01,2=273.00,3=273.00,4=2 73.00,5=273.00,a=45.1,b=50.2,u=54.9,v=63.1,x=65.1,y=65.1<cr><l f> Table 24 Wind Configuration Settings Field Character Field Name Description g Strategy l Pulse length t Single transducer mode 0..5 a,b u,v x,y Zero adjustment Detect level btw. N and E Detect level btw. E and S Detect level btw. S and N A=All, N=North, E=East, S=South N=Normal,auto, A=Adjusted on half, S=Short, E=Extended, T=Test A=All, N=North, E=East, S=South 1...655.35 us (default 273.00 us) 0...100 % (default 70 %) 0...100 % (default 70 %) 0...100 % (default 70 %) 164 __________________________________________________________________M210906EN-A Appendix E ______________________________________________________ factory configurations PTU Configuration Settings 0TF!0TF,n=A0430432 <cr><lf> Table 25 PTU Configuration Settings Field Character Field Name Description n PTU serial number A,B,...=2005,2006..., 1..52 = week, 1...7 = weekday , 1...9999 = serial number Rain Configuration Settings 0RF!0RF,p=1.0,n=3.0,d=N,f=0<cr><lf> Table 26 Rain Configuration Settings Field Character Field Name Description p,n d Positive and negative gain Bypass all hits f Wind filter bypass 0.1...25.5 (p=1.0, n=1.0) Y=Enabled, N=(default) Disabled 0,1...4 (0=wind depended, 1,2,3,4=threshold level) Supervisor Settings 0SF!0SF,t=19.8,b=17159,l=-4.0,m=0.0,h=4.0<cr><lf> Table 27 General Unit Settings Field Character Field Name Description t b l Heat control calibration temp. Direct ADC value of temp.diode Defrosting limit w. 50% duty cycle Heating limit w. full power Heating limit w. 50% duty cycle -50.0...+60.0 °C (calibrate to Ta) 0...4096 -100.0 ...[m] °C (default -4.0 °C) m h [l]...[h] °C(default 0.0 °C) [m]...100.0 °C (default 4.0 °C) VAISALA ______________________________________________________________________ 165 User’s Guide ______________________________________________________________________ 166 __________________________________________________________________M210906EN-A ">

Public link updated
The public link to your chat has been updated.
Advertisement
Key features
- Compact design
- Measures 6 weather parameters
- IP65/IP66 rated housing
- Optional heating for sensors
- Selectable communication protocols
- Windows® based configuration tool available
Frequently asked questions
The WXT520 measures wind speed and direction, precipitation, atmospheric pressure, temperature and relative humidity.
The WXT520 supports SDI-12, ASCII automatic & polled and NMEA 0183 with query option.
The WXT520 can be configured using the optional Vaisala Configuration Tool software, which provides a user-friendly interface for changing device and sensor settings.
The optional heating function helps to improve the accuracy of measurements by preventing ice buildup on the wind and precipitation sensors in cold weather.
The WXT520 is IP65/IP66 rated, which means it is protected against dust and water ingress.