User manual VAISALA WMT52

[. . . ] USER'S GUIDE Vaisala WINDCAP® Ultrasonic Wind Sensor WMT52 M210925EN-A PUBLISHED BY Vaisala Oyj P. O. Box 26 FIN-00421 Helsinki Finland Phone (int. ): Fax: +358 9 8949 1 +358 9 8949 2227 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. 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 . [. . . ] = = = = Device address Measurement break command 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 _______________________________________________________________________ 63 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 95. Table 6 Abbreviation Sn Sm Sx Dn Dm Dx Th Vh Vs Id Name Wind speed minimum Wind speed average Wind speed maximum Wind direction minimum Wind direction average Wind direction maximum Heating temperature Heating voltage Supply voltage Information field Abbreviations and Units Unit m/s, km/h, mph, knots m/s, km/h, mph, knots m/s, km/h, mph, knots deg deg deg °C, °F V V alphanumeric Status1 #, M, K, S, N #, M, K, S, N #, M, K, S, N #, D #, D #, D #, C, F #, N, V, W, F2 V 1. The letters in the status field indicate the Unit, the # character indicates invalid data. 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. Device Address (?) This command is used to query the address of the device on the bus. <cr><lf> = = Device address query command Command terminator 64 ___________________________________________________________________M210925EN-A Chapter 7 __________________________________________________ Getting the Data Messages The response: b<cr><lf> where b <cr><lf> Example: ?<cr><lf> 0<cr><lf> If more than one sensor is connected to the bus, see Appendix A, Networking, on page 121. If you need to change the device address, see Changing the Communication Settings (aXU) on page 59. = = Device address (default = 0) Response terminator. Acknowledge Active Command (a) This command is used to ensure that a device is responding to a data recorder or another device. Command format: a<cr><lf> where a <cr><lf> = = Device address Command terminator The response: a<cr><lf> where a <cr><lf> Example: 0<cr><lf> 0<cr><lf> = = Device address Response terminator VAISALA _______________________________________________________________________ 65 User's Guide ______________________________________________________________________ Wind Data Message (aR1) With this command you can request the wind data message. Command format: aR1<cr><lf> where a R1 <cr><lf> = = = Device address Wind message query command 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 R1 Dn Dm Dx Sn Sm Sx <cr><lf> = = = = = = = = = Device address Wind message query command Wind direction minimum (D = degrees) Wind direction average (D = degrees) Wind direction maximum (D = degrees) Wind speed minimum (M = m/s) Wind speed average (M = m/s) Wind speed maximum (M = m/s) Response terminator To change the parameters and units in the response message and to make other sensor settings, see section Wind Sensor on page 95. 66 ___________________________________________________________________M210925EN-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 R5 <cr><lf> = = = Device address Supervisor message query command 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 R5 Th Vh Vs Vr <cr><lf> Id = = = = = = = = Device address Supervisor message query command Heating temperature (C = °C) Heating voltage (N = heating is off) Supply voltage (V = V) 3. 5 V reference voltage (V = V) Response terminator Information field To change the parameters and units in the response message and to make other settings, see section Supervisor Message on page 101. The content of the parameter "Id" is a text string which can be modified by using the Vaisala Configuration Tool only. 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 _______________________________________________________________________ 67 User's Guide ______________________________________________________________________ Combined Data Message (aR) With this command you can request all individual messages aR1 and aR5 with just one command. Command format: aR<cr><lf> where a R <cr><lf> = = = Device address (default = 0) Combined message query command Command terminator Example of the response: 0R1, Dm=027D, Sm=0. 1M<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 and supervisor data. Command format: aR0<cr><lf> where a R0 <cr><lf> = = = Device address Composite data message query command Command terminator Example of the response (the parameters included can be chosen from the full parameter set of the commands aR1 and aR5): 0R0, Dx=005D, Sx=2. 8M, Th=23. 6C<cr><lf> For selecting the parameter set in the response message, see Chapter 8, Sensor and Data Message Settings, on page 95. 68 ___________________________________________________________________M210925EN-A Chapter 7 __________________________________________________ Getting the Data Messages 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. For more information about the CRC-computation see Appendix C, CRC-16 Computation, on page 133. Requesting a wind data message with a CRC: Command format: ar1xxx<cr><lf> where a r1 xxx <cr><lf> = = = = Device address Wind message query command Three-character CRC for ar1 command 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. Example of asking the CRC for the wind data message query ar1: Command format: ar1yyy<cr><lf> where a r1 yyy <cr><lf> = = = = Device address Wind message query command Arbitrary three-character CRC Command terminator VAISALA _______________________________________________________________________ 69 User's Guide ______________________________________________________________________ Response: atX, Use chksum GoeIU~<cr><lf> where a tX, Use chksum Goe IU~ <cr><lf> = = = = = Device address Text prompt Correct three-character CRC for the ar1 command Three-character CRC for the response message Response terminator Example of the other data query commands with CRC (when the device address is 0): Supervisor query Combined message query = = 0r5Kcd<cr><lf> 0rBVT<cr><lf> 0r0Kld<cr><lf> Composite data message query = 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 95. Automatic Mode When automatic ASCII protocol is selected the sensor sends data messages at user configurable update intervals. [. . . ] 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 27 SDI-12 Timing Diagram VAISALA ______________________________________________________________________ 131 User's Guide ______________________________________________________________________ - 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). [. . . ]