User manual VAISALA WAC155

[. . . ] USER'S GUIDE Vaisala Serial Wind Transmitter WAC155 M210822EN-A PUBLISHED BY Vaisala Oyj P. O. Box 26 FIN-00421 Helsinki Finland Visit our Internet pages at http://www. vaisala. com/ © Vaisala 2007 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. [. . . ] For example, enabling sensor heating without connecting the heating power will cause an error state. Howerver, if the problem is with the operating power, the service connection may not be available even if the LED is flashing. If the signal cable from the WAC155 transmitter is connected to a data collection system and the system is powered up, check that the wind readings react correctly. For testing the wind vane, hold the vane in a few fixed angles and verify the data. 30 ___________________________________________________________________M210822EN-A Chapter 4 ________________________________________________________________ Operation CHAPTER 4 OPERATION This chapter contains information that is needed to operate the Vaisala Serial Wind Transmitter WAC155. User Interface The WAC155 does not provide a direct user interface, except for a status indicator LED on the component board. The LED will flash green when the operational status is OK, and red when there is an error condition. The LED is activated for five minutes after the transmitter is powered up. Service personnel must connect to the service connection to resolve the problem. These connections are described in the next section. Communication Interfaces The WAC155 transmitter communicates over a half-duplex RS-485 interface. The WAC155 can be configured to send wind data messages at regular intervals (auto-transmit mode), and it can provide the data as a response to an MWV query. In addition, a service interface is available for configuration and status information. VAISALA _______________________________________________________________________ 31 User's Guide ______________________________________________________________________ More than one transmitter can be connected to a single RS-485 bus. In the case of single transmitter, the auto-transmit mode can be used (the device transmits data messages with configured interval). If there are several transmitters in the same bus, auto-transmission may not be enabled, and data can be only polled by query. Each device in the same bus has a unique configurable ID, containing 1. . 5 characters. Alphabetical characters a-z and A-Z (case-sensitive) are accepted, as well as numbers 0-9. Table 4 Property Baud rate Data bits Parity Stop bits WAC155 Default Serial Communication Settings Description / Value 9600 8 none 1 NMEA Message Format The NMEA specification defines wind speed and angle message MWV as follows: $WIMWV, <a. a>, <R>, <s. s>, <U>, <S>*<CS><cr><lf> where $WIMWV = <a. a> <R> <s. s> <U> <S> * <CS> = = = = = = = Fixed text at the start of the message Wind angle, 0. . 359 degrees Reference: R=relative, T=theoretical Wind speed Units: K=km/h, M = m/s, N=knots Status: A=valid, V=invalid Asterisk, indicating that the next field is the checksum Two character checksum for the message The comma ", " is used as a separator between the fields. Here are some examples of MWV messages output by the WAC155: 32 ___________________________________________________________________M210822EN-A Chapter 4 ________________________________________________________________ Operation $WIMWV, 39, R, 1. 3, M, A*06 $WIMWV, 39, R, 0. 5, M, A*01 $WIMWV, 61, R, 1. 0, M, A*08 $WIMWV, 59, R, 1. 2, M, A*01 $WIMWV, 53, R, 1. 5, M, A*0c $WIMWV, 46, R, 1. 2, M, A*0f $WIMWV, 70, R, 1. 1, M, A*09 Polling Data using a Query Polling for the MWV messages can be done using the following command: $WIP<ID>Q, *<CS><cr><lf> where $WIP= <ID> = Q * = = Fixed text at the start of the query Transmitter device ID Marks the message as a query Asterisk, indicating that the next field is the checksum Two character checksum for the device ID <CS>= The data in the response follows the MWV message format, but the header is slightly different: $P<ID>MWV, <a. a>, <R>, <s. s>, <U>, <S>*<CS><cr><lf> where $P = Fixed text at the start of the response Transmitter device ID Marks the message as a wind speed and angle message <ID> = MWV = After receiving a query that uses its device ID, the transmitter will reply with an MWV message containing the wind data. However, if you have not defined any messages of the type mwvmessage using the SETMES command, the transmitter will not respond. Example polling command for transmitter with device ID "A": $WIPAQ, *72 VAISALA _______________________________________________________________________ 33 User's Guide ______________________________________________________________________ Example response: $PAMWV, 50, R, 0. 0, M, A*04 Table 5 on page 34 provides checksums and polling strings for some typical device IDs. Table 5 A B C D E F G H I J K L M N O Checksum table Checksum <CS> Polling String 72 71 70 77 76 75 74 7B 7A 79 78 7F 7E 7D 7C $WIPAQ, *72<cr><lf> $WIPBQ, *71<cr><lf> $WIPCQ, *70<cr><lf> $WIPDQ, *77<cr><lf> $WIPEQ, *76<cr><lf> $WIPFQ, *75<cr><lf> $WIPGQ, *74<cr><lf> $WIPHQ, *7B<cr><lf> $WIPIQ, *7A<cr><lf> $WIPJQ, *79<cr><lf> $WIPKQ, *78<cr><lf> $WIPLQ, *7F<cr><lf> $WIPMQ, *7E<cr><lf> $WIPNQ, *7D<cr><lf> $WIPOQ, *7C<cr><lf> ID Character <id> Service Connection The service connection allows you to configure the device and gather status information. The same physical RS-485 interface connection is used for both the data transmission and the service connection. When the service connection is opened (using the OPEN command), the data transmission and query are disabled as long as the service connection remains open. When you change any parameters using the service connection, remember that a reset (or a power-up) is required to take the new parameters into use. [. . . ] RESET <cr> Example: >RESET Wait 5 seconds delay. . . ERRS When issued alone without the [mask] option, the ERRS command returns the current error status of the transmitter. Possible errors, their codes, and the corresponding hexadecimal values are described inTable 10 on page 52. You can use the [mask] option to define the set of errors that causes NMEA messages to be marked as invalid. The error mask is a hexadecimal number formed by combining the hexadecimal values of the desired errors. [. . . ]