Vaisala PWD22/52 User manual

USER'S GUIDE
Vaisala Present Weather Detecto
r
PWD22/52
M210543EN-E

PUBLISHED BY
Vaisala Oyj Phone (int.): [phone]
P.O. Box 26 Fax: [phone]
FI-00421 Helsinki
Finland
Visit our Internet pages at www.vaisala.com.
© Vaisala 2012
No part of this manual may be reproduced, published or publicly displayed in any form
or by any means, electronic or mechanical (including photocopying), nor may its
contents be modified, translated, adapted, sold or disclosed to a third party without prior
written permission of the copyright holder. Translated manuals and translated portions
of multilingual documents are based on the original English versions. In ambiguous
cases, the English versions are applicable, not the translations.
The contents of this manual are subject to change without prior notice.
This manual does not create any legally binding obligations for Vaisala towards
customers or end users. All legally binding obligations and agreements are included
exclusively in the applicable supply contract or the General Conditions of Sale and
General Conditions of Service of Vaisala.

________________________________________________________________________________
VAISALA ________________________________________________________________________ 1
Table of Contents
CHAPTER 1
GENERAL INFORMATION............................................................................ 9
About This Manual ................................................................... 9
Contents of This Manual ....................................................... 9
Version Information ............................................................. 10
Related Manuals ................................................................. 10
Documentation Conventions ............................................... 10
Safety....................................................................................... 11
ESD Protection.................................................................... 13
Recycling ................................................................................ 13
Regulatory Compliances ....................................................... 14
Trademarks ............................................................................. 14
License Agreement ................................................................ 14
Warranty.................................................................................. 14
CHAPTER 2
PRODUCT OVERVIEW................................................................................ 15
Introduction to Vaisala Present Weather Detector
PWD22/52 ................................................................................ 15
Hardware Structure ................................................................ 16
Using PWD22/52................................................................. 16
Product Nomenclature........................................................... 17
CHAPTER 3
FUNCTIONAL DESCRIPTION..................................................................... 19
Optical Measurements ........................................................... 21
Optical Arrangement ........................................................... 21
Transmitter Unit PWT11...................................................... 21
Light Receiver ..................................................................... 22
Additional Measurements ..................................................... 22
Vaisala RAINCAP®Rain Sensor......................................... 22
Background Luminance Sensor PWL111 (optional)........... 23
BLSC Command ............................................................ 24
Continuous Mode...................................................... 24
Day/night Switch Mode ............................................. 24
Disabling PWL111 .................................................... 24
BLCAL Command .......................................................... 24
Temperature Sensor ........................................................... 25
Applications............................................................................ 25
Internal Monitoring................................................................. 26
Built-in Tests........................................................................ 26
Memory Tests...................................................................... 27
Signal Monitoring ................................................................ 27
Hardware Monitoring........................................................... 27
Monitoring Contamination ................................................... 28

USER'S GUIDE____________________________________________________________________
2 ___________________________________________________________________ M210543EN-E
CHAPTER 4
INSTALLATION............................................................................................29
Selecting Location..................................................................29
Grounding and Lightning Protection ...................................31
Equipment Grounding .........................................................31
Internal Grounding of PWD22/52 ........................................31
Grounding the Remote Units and the Communication
Cable ...................................................................................31
Installation Procedure............................................................32
Unpacking Instructions ........................................................32
Unpacking Procedure.....................................................32
Storage...........................................................................32
Mounting..............................................................................33
Connections............................................................................34
Connecting Cables ..............................................................34
Basic Wiring ...................................................................35
Supplying Power to PWD22/52 ...........................................37
Internal Heaters and Heaters for PWL111 Option .........37
PWH111 Hood Heaters..................................................38
Communication Options ......................................................38
Serial Communication Settings ......................................38
Serial Transmission RS-232...........................................38
Serial Multipoint Transmission RS-485 ..........................39
Connection of the Maintenance Terminal ......................39
Relay Controls .....................................................................40
RELAY Command ..........................................................43
Initial Settings ......................................................................43
Weather Parameters ......................................................44
Verification...........................................................................45
CHAPTER 5
OPERATION.................................................................................................47
Getting Started........................................................................47
Operating Instructions ...........................................................48
Entering and Exiting the Command Mode ..........................49
OPEN .............................................................................49
CLOSE ...........................................................................49
Message Types ...................................................................50
Message 0......................................................................51
Message 1......................................................................51
Message 2......................................................................52
Message 3......................................................................52
Message 4......................................................................52
Messages 5 and 6 ..........................................................53
Message 7......................................................................53
Automatic Message Sending...............................................54
Message Polling .............................................................55
Precipitation Sums .................................................................57
List of Commands ..................................................................57
PWD22/52 Command Set ...................................................57
HELP ..............................................................................57
MES................................................................................58
AMES .............................................................................58
Weather Related Commands ..............................................59
WPAR.............................................................................59

________________________________________________________________________________
VAISALA ________________________________________________________________________ 3
WSET............................................................................. 59
CLRS.............................................................................. 61
System Configuration Commands ...................................... 62
PAR................................................................................ 62
CONF ............................................................................. 62
Hood Heaters ................................................................. 67
BAUD ............................................................................. 67
Analog Output ..................................................................... 67
Analog Output Modes .................................................... 69
Mode 0 ...................................................................... 69
Mode 1 ...................................................................... 70
Mode 2 ...................................................................... 70
Mode 3 ...................................................................... 71
Mode 4 ...................................................................... 71
Analog Output Calibration.............................................. 71
Maintenance Commands .................................................... 73
STA ................................................................................ 73
CAL ................................................................................ 74
CLEAN ........................................................................... 75
ZERO ............................................................................. 75
CHEC ............................................................................. 76
DRY ON and WET ......................................................... 76
DRY ON .................................................................... 76
WET .......................................................................... 77
HEAT.............................................................................. 77
Other Commands................................................................ 78
TIME............................................................................... 78
DATE.............................................................................. 78
RESET ........................................................................... 79
VER................................................................................ 79
CHAPTER 6
MAINTENANCE ........................................................................................... 81
Periodic Maintenance ............................................................ 81
Cleaning .............................................................................. 82
Cleaning Lenses and Hoods.......................................... 82
Cleaning RAINCAP®...................................................... 83
Calibration............................................................................... 83
Visibility Calibration ............................................................. 83
Calibration Check Procedure ......................................... 84
Calibration Procedure .................................................... 85
Removing and Replacing ...................................................... 86
Removing and Replacing the Optical Units ........................ 86
Removing PWT11.......................................................... 87
Removing PWC22/52 .................................................... 88
Replacing RAINCAP®.................................................... 91
CHAPTER 7
TROUBLESHOOTING ................................................................................. 93
Common Problems ................................................................ 93
Message Indicating Warning or Alarm ................................ 93
Message Missing ................................................................ 93
Message Exists but Visibility Value Does Not..................... 94
Visibility Value is Continuously Too Good .......................... 95
Visibility Constantly Too Low .............................................. 95

USER'S GUIDE____________________________________________________________________
4 ___________________________________________________________________ M210543EN-E
PWD22/52 Reports Precipitation When There Is None ......96
PWD22/52 Reports Frozen Precipitation during Rain.........96
PWD22/52 Electrical Troubleshooting.................................97
Technical Support ..................................................................98
Product Returns......................................................................98
CHAPTER 8
TECHNICAL DATA ......................................................................................99
Specifications .........................................................................99
Mechanical Specifications ...................................................99
Electrical Specifications.....................................................100
Optical Specifications ........................................................100
Visibility Measurement Specifications ...............................101
Weather Sensing Specifications........................................101
Environmental Specifications ............................................102
APPENDIX A
VALUES FOR INTERNAL MONITORING .................................................103
APPENDIX B
PWC22/52 CONNECTORS AND JUMPER SETTINGS ............................107
APPENDIX C
NWS AND WMO CODE TABLES..............................................................111
INDEX .........................................................................................................113

________________________________________________________________________________
VAISALA ________________________________________________________________________ 5
List of Figures
Figure 1 PWD22/52 Present Weather Detector ..................................... 16
Figure 2 PWD22/52 Block Diagram........................................................ 20
Figure 3 PWD22/52 Optical System....................................................... 21
Figure 4 RAINCAP®Block Diagram ....................................................... 23
Figure 5 PWL111 Block Diagram ........................................................... 25
Figure 6 LED Indicators on the PWC22/52 Board.................................. 26
Figure 7 Recommended Location of PWD22/52 Sensor. ...................... 30
Figure 8 Installing PWD22/52 to the Support Arm ................................. 33
Figure 9 Installing the Subassembly to the Mast with the Vaisala
Clamp Assembly ...................................................................... 33
Figure 10 Testing the Connector .............................................................. 34
Figure 11 Cabling Principle ...................................................................... 36
Figure 12 Maintenance Cable .................................................................. 36
Figure 13 PWL111 jumper settings. ......................................................... 37
Figure 14 Relay Connection: PWD22/52 Supplies................................... 41
Figure 15 Relay Connection: External Relay Supply ............................... 42
Figure 16 Illustration of Contents of Messages 0, 1, and 2...................... 50
Figure 17 Analog Current Output Connection .......................................... 68
Figure 18 Analog Current Output Connection
(External Current Source) ........................................................ 69
Figure 19 Assembling the Opaque Glass Plates...................................... 85
Figure 20 Removing PWT11 .................................................................... 87
Figure 21 Opening Box Screws (1) .......................................................... 88
Figure 22 Removing the PWC15PB Protection Board............................. 89
Figure 23 Removing the PWC22/52 Board .............................................. 90
Figure 24 Removing the Rain Sensor ...................................................... 91
Figure 25 Location of Jumpers and Connectors on the PWC22/52
Processor/Receiver Board ..................................................... 109

USER'S GUIDE____________________________________________________________________
6 ___________________________________________________________________ M210543EN-E
This page intentionally left blank.

________________________________________________________________________________
VAISALA ________________________________________________________________________ 7
List of Tables
Table 1 Manual Revisions ..................................................................... 10
Table 2 Related Manuals ...................................................................... 10
Table 3 PWD Sensor Series Model and Performance Table................ 15
Table 4 Vaisala Present Weather Detector
PWD22/52 Nomenclature......................................................... 17
Table 5 Nomenclature for Options of the Vaisala Present Weather
Detector PWD Family............................................................... 17
Table 6 Receptable Connector Default Wiring...................................... 35
Table 7 Control Logic of Relay Controls 1 and 2 .................................. 40
Table 8 Control Logic of Relay Controls 1, 2, and 3 ............................. 41
Table 9 Default Communication Settings.............................................. 43
Table 10 Commands for Changing Default Settings............................... 44
Table 11 Commands for Displaying and Changing Parameters............. 44
Table 12 Initial Settings and Corresponding Commands........................ 48
Table 13 Commands for Routine Maintenance Operations.................... 48
Table 14 Command Set .......................................................................... 57
Table 15 Hardware Error Texts ............................................................... 74
Table 16 Warnings .................................................................................. 74
Table 17 PWD22/52 Specifications........................................................ 99
Table 18 PWD22/52 Electrical Specifications ....................................... 100
Table 19 Optical Specifications of the Light Transmitter....................... 100
Table 20 Optical Specifications of the Light Receiver........................... 101
Table 21 Visibility Measurement Specifications .................................... 101
Table 22 Weather Sensing Specifications ............................................ 101
Table 23 Environmental Specifications ................................................. 102
Table 24 Values from STA message for Internal Monitoring ................ 103
Table 25 Internal Weather Types and Supported NWS Codes ............ 111
Table 26 WMO SYNOP Codes (Table 4680, WaWa) Used by
PWD22/52 .............................................................................. 111
Table 27 WMO METAR Codes (Table 4678) Used by PWD22/52....... 112

USER'S GUIDE____________________________________________________________________
8 ___________________________________________________________________ M210543EN-E
This page intentionally left blank.

Chapter 1 ________________________________________________________ General Information
VAISALA ________________________________________________________________________ 9
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 Present Weather Detector PWD22/52.
Contents of This Manual
This manual consists of the following chapters:
- Chapter 1, General Information, provides general notes for the
product.
- Chapter 2, Product Overview, introduces Vaisala Present Weather
Detector PWD22/52 features, advantages, and the product
nomenclature.
- Chapter 3, Functional Description, describes the functionality of the
product.
- Chapter 4, Installation, provides you with information that is intended
to help you install this product.
- Chapter 5, Operation, contains information that is needed to operate
this product.
- Chapter 6, Maintenance, provides information that is needed in basic
maintenance of the product.
- Chapter 7, Troubleshooting, describes common problems, their
probable causes and remedies, and provides contact information for
technical support.
- Chapter 8, Technical Data, provides the technical data of PWD22/52.
- Appendix A includes Values for Internal Monitoring.
- Appendix B includes Jumper Settings.
- Appendix C includes NWS and WMO Code Tables.
- INDEX is located at the end of the manual.

USER'S GUIDE____________________________________________________________________
10 __________________________________________________________________ M210543EN-E
Version Information
Table 1 Manual Revisions
Manual Code Description
M210543EN-E August 2012. This manual. Added information
regarding PWC15PB.
M210543EN-D Previous version.
Related Manuals
Table 2 Related Manuals
Manual Code Manual Name
M210542EN Vaisala Present Weather Detector PWD12, User's
Guide
M210541EN Vaisala Visibility Sensor PWD10/20/50, User's
Guide
Documentation Conventions
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.

Chapter 1 ________________________________________________________ General Information
VAISALA _______________________________________________________________________ 11
Safety
Vaisala Present Weather Detector PWD22/52 delivered to you has been
tested for safety and approved as shipped from the factory. Note the
following precautions:
WARNING The chassis of the PWD22/52 must be connected to a good electrical
earth.
WARNING Do not touch the surface of the RAINCAP®Rain sensor plate. When you
need to touch the sensors plate, for example during cleaning, touch first
metallic part of PWD22/52 to discharge possible electrostatic load of
your body. The measuring principle does not allow for proper ESD
protection.
WARNING Do not operate the equipment in the presence of flammable gases or
fumes. Operation of any electrical instrument in such an environment
constitutes a definite safety hazard.
WARNING A lightning strike through a communication wire can cause voltage surge
dangerous to life at remote sites if the remote units are not properly
grounded.
CAUTION Do not modify or substitute parts in the instrument. Contact Vaisala or its
authorized representative for repairs.
CAUTION The component boards including CMOS microchips should be
transported and stored in conductive packages. Although new CMOS
devices are protected against overvoltage damages caused by static
electric discharge of the operator, careful handling is recommended: the
operator should be properly grounded. Unnecessary handling of
component boards should be avoided.

USER'S GUIDE____________________________________________________________________
12 __________________________________________________________________ M210543EN-E
CAUTION Tighten the connector properly. The cable connector must not swing in
relation to the fixed connector.
CAUTION Servicing the equipment must be performed by qualified personnel.
RADIO FREQUENCY INTERFERENCE STATEMENT (USA)
The United States Federal Communications Commission (in 47 CFR
15.838) has specified that the following notice must be brought to the
attention of users of this kind of a product in the USA:
Federal communications commission radio frequency interference
statement
This equipment generates and uses radio frequency energy and if not
installed and used properly, that is in strict accordance with the
manufacturer's instructions, may cause interference to radio and
television reception. The Present Weather Detector is designed to
provide reasonable protection against such interference in an airport
installation. However, there is no guarantee that interference will not
occur in a particular installation. If this equipment causes interference to
radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
- Reorient the receiving antenna
- Relocate this device with respect to the receiver
- Move this device away from the receiver
If necessary, the user should consult the dealer or an experienced
radio/television technician for additional suggestions.

Chapter 1 ________________________________________________________ General Information
VAISALA _______________________________________________________________________ 13
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
to the equipment chassis before touching the boards. Ground yourself
with a wrist strap and a resistive connection cord. When neither of the
above is possible, 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.

USER'S GUIDE____________________________________________________________________
14 __________________________________________________________________ M210543EN-E
Regulatory Compliances
The PWD series visibility sensors and present weather detectors are in
conformity with the provisions of the following EU directive(s):
- EMC Directive (2004/108/EC)
Conformity is shown by compliance with the following standards:
- EN 61326-1:2006-04 Electrical equipment for measurement, control
and laboratory use - EMC requirements - for use in industrial
locations.
- EN 55022:2006 + Am 1:2007 to EN55022:2006 Class B. Information
technology equipment - Radio disturbance characteristics - Limits and
methods of measurement.
Trademarks
RAINCAPis a registered trademark of Vaisala. Microsoft, Windows®,
and Windows NT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.
Warranty
Visit our Internet pages for standard warranty terms and conditions:
www.vaisala.com/warranty.
Please observe that any such warranty may not be valid in case of
damage due to normal wear and tear, exceptional operating conditions,
negligent handling or installation, or unauthorized modifications. Please
see the applicable supply contract or Conditions of Sale for details of the
warranty for each product.

Chapter 2 __________________________________________________________ Product Overview
VAISALA _______________________________________________________________________ 15
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces Vaisala Present Weather Detector PWD22/52
features, advantages, and the product nomenclature.
Introduction to Vaisala Present Weather
Detector PWD22/52
PWD22/52 is an intelligent, multi-variable sensor for automatic weather
observing systems. The sensor combines the functions of a forward
scatter visibility meter and a present weather sensor. PWD22/52 can
measure the intensity and amount of both liquid and solid precipitation. If
the detector is equipped with a background luminance sensor, it can also
measure ambient light.
PWD22/52 suitable for automatic weather station applications especially
for low-power requirement installations.
Table 3 PWD Sensor Series Model and Performance Table
Model Performance
Visibility Sensor PWD10 Visibility range 10 m ... 2000 m
Present Weather Detector PWD12 Visibility range 10 m ... 2000 m
4 different precipitation types
Visibility Sensor PWD20 Visibility range 10 m ... 20000 m
Visibility Sensor PWD50 Visibility range 10 m ... 35000 m
Present Weather Detector PWD22 Visibility range 10 m ... 20000 m
7 different precipitation types
Present Weather Detector PWD22M For Vaisala TACMET stations
Present Weather Detector PWD52 Visibility range 10 m ... 35000 m
7 different precipitation types
The versatility of PWD22/52 is achieved with a unique operating
principle. PWD22/52 measures an estimate of the precipitation water
content with a capacitive device Vaisala RAINCAP®Rain Sensor and
combines this information with optical scatter and temperature
measurements. These three independent measurements together provide
sufficiently data for an accurate evaluation of prevailing visibility and
weather type.

USER'S GUIDE____________________________________________________________________
16 __________________________________________________________________ M210543EN-E
Hardware Structure
PWD22/52 is a self-contained instrument that can be fastened to the side
of the mast and into a cross arm using the mounting clamps.
0308-002
Figure 1 PWD22/52 Present Weather Detector
The following numbers refer to Figure 1 above.
1 = Transmitter
2 = Controller/Receiver
3 = PWR211 Vaisala RAINCAP®Rain Sensor
(PWR111 in PWD22M)
4 = Pt100 temperature sensor in the tube
5 = Mounting clamp
6 = Hood heaters (optional)
7 = Place for Vaisala Luminance Sensor PWL111 (optional)
Using PWD22/52
PWD22/52 is typically used as a component of a weather observing
system.
The PWD22/52 output is either a digital serial interface or an analog
current signal. The digital serial interface can be configured into two
different operating modes: the sensor can be set to send a data message
automatically at selected intervals, or PWD22/52 can be polled by the
host computer. The same serial line is also used as an operator interface.
The analog current signal can be used to report the prevailing visibility.
Three relay controls can be used, driven by visibility limits.
The operator controls and checks the operation of PWD22/52 using a
maintenance terminal. A set of built-in commands and test routines are
provided for configuring and monitoring the multiple functions of
PWD22/52.

Chapter 2 __________________________________________________________ Product Overview
VAISALA _______________________________________________________________________ 17
The standard data messages contain a status character for indicating
faults detected by the internal diagnostics. If the error status is set, the
operator can display a special status message, which contains the detailed
results of the diagnostics and a written description of the fault. With this
information the operator can take corrective action or give the
maintenance personnel advice.
Product Nomenclature
Table 4 Vaisala Present Weather Detector PWD22/52
Nomenclature
Code Common Name Description
PWT11 Transmitter LED Transmitter circuit board.
PWC22 Controller/Receiver Controller and photo diode
circuit board for PWD22.
PWC52 Controller/Receiver Controller and photo diode
circuit board for PWD52.
PWR211 RAINCAP®Double-Plate
Rain Sensor
A capacitive detector to sense
water droplets and/or moisture.
Two plate in a 90-degree angle
towards each other.
Table 5 Nomenclature for Options of the Vaisala Present
Weather Detector PWD Family
Code Common Name Description
PWL111 Background Luminance
Sensor
PWH111 Hood Heater Foils
PWA11 Calibration Set Includes a pair of
precalibrated scatterers, a
piece of cloth for cleaning the
lenses and tools.
16385ZZ RS-232 (9-pin)
maintenance cable
Connects to standard PC
communication port.
APPKP60-set -1/2
75-set -1/2
100-set -1/2
Attachment clamp 60 mm, 75 mm or 100 mm
clamp according to the mast
diameter

USER'S GUIDE____________________________________________________________________
18 __________________________________________________________________ M210543EN-E
This page intentionally left blank.