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Related Manuals for Vaisala FD12P
Summary of Contents for Vaisala FD12P
- Page 1 Weather Sensor FD12P UIDE M210296en-A May 2002...
- Page 2 The contents are subject to change without prior notice. Please observe that this manual does not create any legally binding obligations for Vaisala towards the customer or end user. All legally binding commitments and agreements are included exclusively in the applicable supply contract or...
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Page 3: Table Of Contents
PRODUCT OVERVIEW ................17 Introduction................17 Hardware Structure .............17 Sensing Elements ............19 Electronics Enclosure .............20 Structural Elements ............20 Operating Principle ..............21 Using FD12P ...............22 Equipment Nomenclature ............23 Specifications .................24 Mechanical Specifications ...........24 Electrical Specifications............24 Optical Specifications ............25 Capabilities and Limitations..........26 Visibility Measurement Specifications .........26 Weather Sensing Specifications..........26... - Page 4 Connecting Cables.............. 43 Basic Wiring..............43 Communication Cable EMC-shielding......46 Connecting a Background Luminance Sensor or a Day/Night Switch to FD12P ........... 48 Communication Options ............. 50 Serial Communications Settings........50 Serial Transmission RS-232 .......... 50 Serial Multipoint Transmission RS-485 ......51 Modem DMX21..............
- Page 5 DRY and WET Commands ..........89 AN Command ..............90 Analog Output Commands ..........91 Analog Output Calibration ..........91 Data Scaling ..............92 Hardware Check.............92 Other Commands ..............93 TIME Command .............93 DATE Command ............93 RESET Command............94 CHAPTER 5 FUNCTIONAL DESCRIPTION ..............95 General..................95 Optical Measurement .............96 VAISALA _________________________________________________________________________ 5...
- Page 6 User's Guide _______________________________________________________________________ Optical Arrangement ............96 FDT12B Transmitter Unit ............ 96 FDR12 Receiver Unit ............98 Additional Measurements ............. 99 General ................99 DRI21 Interface Board ............99 DRD12 Rain Detector ............100 DTS14B Temperature Sensor .......... 101 FDP12 Control Unit .............. 101 Measurement Signal Processing........
- Page 7 Have Jumper Settings Been Changed? ......137 Values for Internal Monitoring..........137 Getting Help ................140 Return Instructions...............140 APPENDIX A NWS AND WMO CODES USED IN FD12P ..........143 The NWS Codes ..............143 APPENDIX B JUMPER SETTINGS AND INTERNAL WIRING........147 CPU Board ................149 DC-Regulator.................149 DRI21 Interface Board ............149...
- Page 8 Figure 22 FDT12B Transmitter Block Diagram ........97 Figure 23 FDR12 Receiver Block Diagram ..........98 Figure 24 DRI21 Block Diagram in the FD12P Application....100 Figure 25 DRD12 Block Diagram............101 Figure 26 FDP12 Control Unit Block Diagram ........102 Figure 27 Optical Raw Data (in Rain) ............
- Page 9 WMO SYNOP Codes (4680, W ) ........144 Table 33 WMO SYNOP Codes (4680, W ) ........144 Table 34 WMO Code Table 4678. Codes Used by FD12P....145 Table 35 CPU Board Jumpers...............149 Table 36 CPU Board Connectors ............149 Table 37 DC-regulator Connectors............149 Table 38 DRI21 Interface Board Jumpers ..........149...
- Page 10 User's Guide _______________________________________________________________________ This page intentionally left blank. ______________________________________________________ M210296en-A...
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Page 11: General Information
- Chapter 6, Maintenance, describes the overall maintenance of the product. - Chapter 7, Troubleshooting, deals with troubleshooting information. - Appendix A, NWS and WMO Codes Used in FD12P - Appendix B, Jumper Settings and Internal Wiring - Appendix C, Transmitter and Receiver Test Points VAISALA ________________________________________________________________________ 11... -
Page 12: Version Information
User's Guide _______________________________________________________________________ Version Information Table 1 Manual Revisions Manual Code Description FD12P-U106en-1.2 Weather Sensor, User's Guide M210296en-A This manual. Related Manuals Table 2 Related Manuals Manual Code Manual Name DMX21T0496-1.1 DMX21 CCITT Modem LM11T0545-1.2 LM11 Background Luminance Meter Safety... -
Page 13: Product Related Safety Precautions
Chapter 1 _________________________________________________________ General Information Product Related Safety Precautions The FD12P Weather Sensor delivered to you has been tested for safety and approved as shipped from the factory. Note the following precautions: WARNING Ground the product, and verify outdoor installation grounding periodically to minimize shock hazard. - Page 14 Do not substitute parts or modify the instrument. Because of the danger of introducing additional hazards, do not modify or substitute parts in the instrument. Contact Vaisala or its authorized representative for repairs to ensure that safety features are maintained.
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Page 15: Radio Frequency Interference Statement (Usa)
ESD Protection Electrostatic Discharge (ESD) can cause immediate or latent damage to electronic circuits. Vaisala products are adequately protected against ESD for their intended use. However, it is possible to damage the product by delivering electrostatic discharges when touching, removing, or inserting any objects inside the equipment housing. -
Page 16: Trademarks
Intel® is a registered trademark of the Intel Corporation in the U.S. and other countries. Warranty For certain products Vaisala normally gives a limited one-year 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. -
Page 17: Chapter 2 Product Overview
Hardware Structure The structural basis of the FD12P is the pole mast that supports the transducer crossarm (FDC115). The crossarm contains the optical VAISALA ________________________________________________________________________ 17... -
Page 18: Figure 1 Fd12P Weather Sensor Site
= DRD12 Rain Detector = DTS14 Temperature Sensor = Pole mast = Electronics enclosure The FD12P Weather Sensor consists of three parts: sensing elements, electronics enclosure, and structural elements. They are described in detail on the next page. ______________________________________________________ M210296en-A... -
Page 19: Sensing Elements
The DRD12 is illustrated in Figure 2 below. The DTS14B Temperature Sensor is a Pt100 thermistor that is used to measure the crossarm temperature. See Figure 2 below. 0201-086 Figure 2 DRD12 Rain Detector and DTS14B Temperature Sensor VAISALA ________________________________________________________________________ 19... -
Page 20: Electronics Enclosure
ON/OFF switch, which also functions as an automatic fuse. The FDS12 DC Voltage Regulatorconverts the AC or DC input voltage (min. 18 V) to 12 VDC power used by FD12P electronics. The FDS12 also includes one relay used to control heater power. -
Page 21: Operating Principle
Chapter 2 ___________________________________________________________Product Overview Operating Principle The FD12P Weather Sensor is a microprocessor controlled, intelligent sensor combining optical forward scatter measurement, capacitive precipitation sensing, and temperature measurement. The main units of the FD12P are shown in Figure 3 below. 9502-091... -
Page 22: Using Fd12P
The final weather message (SYNOP, METAR) is then coded in the central unit of a weather observation system (for example, Vaisala MILOS 500) or by a human observer using the FD12P as an observation aid. The FD12P output is a digital serial interface, which can be... -
Page 23: Equipment Nomenclature
Termbox-48 Mains and Signal Adapting/extending the local Junction Box cable. Contains heavy-duty transient protection circuitry. FD12MODEM Modem Option For remote communication. FD12PLM11 LM11 Option For ambient light measurement. 16616ZZ Extended Transducer For optional high-mast Cable mounting. VAISALA ________________________________________________________________________ 23... -
Page 24: Specifications
User's Guide _______________________________________________________________________ Specifications Mechanical Specifications - Dimensions: 2.3 m × 1.6 m × 0.6 m (H × W × D) - Weight: 35 kg, excluding the installation plate for the pole mast - Mounting: on a concrete foundation with three ∅16-mm bolts - Material: anodized aluminum, natural gray Electrical Specifications... -
Page 25: Optical Specifications
- Photodiode: PIN 6 DI - Spectral response: max. responsivity at 850 nm, 0.55 A/W (in range 550 ... 1050 nm over 0.3 A/W) - Reception lens diameter: 71 mm - Backscatter light source: near-infrared LED for contamination and blockage measurement VAISALA ________________________________________________________________________ 25... -
Page 26: Capabilities And Limitations
User's Guide _______________________________________________________________________ Capabilities and Limitations Visibility Measurement Specifications Measurement range of Meteorological Optical Range (MOR): - 10 ... 50 000 m according to a 5 % Contrast Threshold Definition Accuracy: - ± 10 %, range 10 ... 10 000 m - ±... -
Page 27: Environmental Specifications
- − 40 ... +55 o C Operating humidity range: - Up to 100 % RH Wind speed: Up to 60 m/s (standard mast) Sun orientation: - Direct and reflected sunlight into the light receiver must be avoided. VAISALA ________________________________________________________________________ 27... - Page 28 User's Guide _______________________________________________________________________ This page intentionally left blank. ______________________________________________________ M210296en-A...
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Page 29: Chapter 3 Installation
Before installation, read section Product Related Safety Precautions on page 13. Organizing Installation Before you begin to install the FD12P Weather Sensor, make a plan of the installation steps. The following is an example of how to organize the installation process. -
Page 30: Location And Orientation
Start-up tests for the system. Location and Orientation The main requirements for the location of the FD12P are as follows: Place the FD12P at a site where the measurements will be representative of the surrounding weather conditions. The ideal site has a minimum clearance of 100 meters from all large buildings and other constructions that generate heat and/or obstruct precipitation droplets. -
Page 31: Figure 4 Recommended Location For The Fd12P
There should be no flashing lights near the sensor. A flashing light can cause errors in detecting precipitation towards No obstacles or reflecting surfaces 0110-178 Figure 4 Recommended Location for the FD12P The following numbers refer to Figure 4 above. Transmitter Receiver VAISALA ________________________________________________________________________ 31... -
Page 32: Grounding And Lightning Protection
User's Guide _______________________________________________________________________ Power supply and communication lines must be available. When the site for the FD12P is selected, take into consideration the available power supply and communication lines. This influences the amount of work and accessories needed and thus, the actual installation costs. -
Page 33: Figure 5 Fd12P Equipment Grounding
Chapter 3 ________________________________________________________________ Installation 0111-001 Figure 5 FD12P Equipment Grounding The following numbers refer to Figure 5 above: Electronics enclosure Junction box (optional) Mains cable Cable tubing Grounding rods Signal cable 16 mm² grounding cables Grounding clamp VAISALA ________________________________________________________________________ 33... -
Page 34: Internal Grounding
Assembling the FD12P on page 40 and Figure 10 on page 43. Grounding for Testing Purposes The FD12P is provided with a two-meter mains cable. The cable has a grounded plug. The plug must be connected only to an outlet that has a ground terminal. -
Page 35: Cable Selection
Chapter 3 ________________________________________________________________ Installation Cable Selection Line Power Cabling The FD12P is supplied with a two-meter power cable. If a local terminal for 115/230 VAC power supply is not available, use an extended mains cable from the FD12P to the nearest power source. -
Page 36: Unloading And Unpacking
Place the packing materials and covers back in the cases and store them for possible reshipment. Storage Information Store the FD12P in its packages in dry conditions, not in the open air. The storage conditions are as follows: - Temperature −40 o C ... 70 o C. -
Page 37: Installation Procedures
Figure 6 below. It is easiest to mount the foundation screws while casting the pad. If the pad was casted earlier, drill three holes into the concrete for the wedge bolts. 0110-179 Figure 6 Casting a Concrete Foundation VAISALA ________________________________________________________________________ 37... -
Page 38: Mounting When Casting The Pad
Reinforcing steel Reinforcing steel or use steel mesh 150 × 150 mm The Installation Set included in the FD12P delivery contains the required equipment both for mounting when casting the pad and mounting to an existing surface. Use the triangle shaped template as an auxiliary device and remove it before mounting the base plate. -
Page 39: Figure 7 Constructing The Fd12P Foundation
Chapter 3 ________________________________________________________________ Installation 0110-180 Figure 7 Constructing the FD12P Foundation VAISALA ________________________________________________________________________ 39... -
Page 40: Assembling The Fd12P
M10, 4 pieces 11 = Baseplate Assembling the FD12P Mount the base plate and level it with the six M16 nuts. Mount the pole mast pedestal and the tilting support on the base plate with four M10 bolts (Figure 7 on page 39, C, top view). -
Page 41: Attaching The Dts14B Temperature Sensor To The Mast
- Push the screw head to the holder with you finger. - Put the holder to the hole in the mast pole. - Slide the holder upwards as long as it goes and hold it there. - Tighten the fixing screw firmly. VAISALA ________________________________________________________________________ 41... -
Page 42: Figure 9 Dts14B And The Sensor Holder Assembly To Mast
User's Guide _______________________________________________________________________ - Insert the crossarm to the pole mast and lock it in the right position with two 8-mm bolts. - Erect the mast. - Lift the DRD12 Rain Detector to an upright position. Tighten the clamp. 0201-088 Figure 9 DTS14B and the Sensor Holder Assembly to Mast The following numbers refer to Figure 9 above:... -
Page 43: Connecting Cables
The following numbers refer to Figure 10 above: Crossarm Ground terminal socket Grounding flat connector Pole mast MIL-connector Connecting Cables Basic Wiring To do the basic wiring, do the following: The electronics enclosure includes a power cable. Remove the plug. VAISALA ________________________________________________________________________ 43... -
Page 44: Figure 11 Cabling Principle
User's Guide _______________________________________________________________________ If you use another, longer cable, make sure to connect the wires in a correct way, especially the protective ground wire (usually yellow-green). Refer to Figure 11 below. Connect the power cord to the screw terminals in a junction box or bring the power line directly to the electronics enclosure. -
Page 45: Figure 12 Line Voltage And On/Off Switches
FDW13 unit (see Figure 12 below). 0110-183 Figure 12 Line Voltage and ON/OFF Switches The following numbers are related to Figure 12 above: Electronics enclosure Pole mast DMX21 modem DC regulator FDW13 ON/OFF switch Line voltage setting FD12P control unit VAISALA ________________________________________________________________________ 45... -
Page 46: Communication Cable Emc-Shielding
User's Guide _______________________________________________________________________ 0110-184 Figure 13 Electronics Enclosure Feedthroughs The following numbers refer to Figure 13 above: Grounding DTS14 cable feedthrough Temperature sensor (TE) Cap (Pg 13.5) of optional opening for the LM11 background luminance meter Main power cable FDC115 transducer cable feedthrough Standard communication cable feedthrough Communication Cable EMC-shielding The electronics enclosure has one cable outlet for a cable diameter... -
Page 47: Figure 14 Cable Grounding Instructions
Tighten the cable with the cable gland and proceed with the wiring. Connect the signal cable to the screw terminals in the electronics enclosure. Ground the signal cable with the same method at both ends. 0205-006 Figure 14 Cable Grounding Instructions VAISALA ________________________________________________________________________ 47... -
Page 48: Connecting A Background Luminance Sensor Or A Day/Night Switch To Fd12P
Figure 16 on page 50. Positive voltage is interpreted as a night condition and the background luminance value in the FD12P output message is set to 0. Negative voltage or an open circuit is interpreted as a day condition and the luminance value is set to 1. -
Page 49: Figure 15 Wiring The Connector For The Lm11 Background Luminance
Chapter 3 ________________________________________________________________ Installation 9610-006 Figure 15 Wiring the Connector for the LM11 Background Luminance Meter VAISALA ________________________________________________________________________ 49... -
Page 50: Communication Options
Communication Options Serial Communications Settings NOTE The factory default settings of the FD12P serial communications port are 300 baud. Even parity is 7 data bits, 1 stop bit. Serial Transmission RS-232 For the RS-232 communication, connect the signal wires to screw terminal X18 (CTR lines not needed) at CPU board FDP12. -
Page 51: Serial Multipoint Transmission Rs-485
In the multidrop configuration, where several FD12P Weather Sensors are on the same communication line, units are differentiated by an ID. Set a different unit ID to each FD12P with the CONF command. Set FD12 P to the polling mode with the AMES 0 2 command. The host system must ask data messages by polling each FD12P. -
Page 52: Modem Dmx21
Figure 19 on page 53. If the X2 jumper is in position 3-4 and if the unit ID is not set, FD12P keeps the modem carrier signal on all the time. Set the FD12P to the polling mode with the AMES 0 2 command. -
Page 53: Figure 19 Wiring The Modem
Usually, the modem of the FD12P operates in the answer mode, and the modem of the host computer in the originate mode. In the standard FD12P system, the S3 switch on the DMX21 board is in the DOWN position and the answer mode is selected. When the switch is in the UP position, the originate mode is selected. -
Page 54: Indicators And Manual Controls
User's Guide _______________________________________________________________________ Indicators and Manual Controls This section describes the alternatives of the indicators and manual controls available in the FD12P DMX21 modem. Indicators The LED indicators of the DMX21 modem are listed and described in Table 8 below. -
Page 55: Analog Transmission
Any computer equipped with a terminal emulation software or a VT100 compatible terminal with the RS-232 serial interface can be used as a maintenance terminal for the FD12P. The optional maintenance cable provides a 9-pin D-connector for the computer and a 3-pin connector for the FD12P. -
Page 56: Startup Testing
15 seconds in the display. Initial Settings The FD12P Weather Sensor is typically interfaced to a host computer or a data logger in an automatic weather observing system. After the physical connection has been made, the communication details can be configured in the FD12P software. -
Page 57: Table 10 Default Communication Settings
No ID set In multipoint communication where several sensors share the same communication line, the FD12P should be used in the polled mode and individual sensors must have distinct identifiers (ID). The baud rate should not be changed if the optional 300-baud modem is used. - Page 58 WSET command. The new scaling factor can be calculated by comparing the FD12P against a reference rain gauge. For details, see the description of the WSET command in section WSET Command on page 73.
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Page 59: Chapter 4 Operation
WMO codes is presented in Appendix A on page 143. User Commands in Normal Operation User intervention is not required in the normal operation of the FD12P Weather Sensor. Operator commands are used only in the initial set- up and during routine maintenance. Several commands are also available for troubleshooting. -
Page 60: Table 13 Settings And Corresponding Commands
User's Guide _______________________________________________________________________ When the sensor has been installed, the user may need to change some of the default settings. For details, see section Initial Settings on page Table 13 below lists the settings and the corresponding commands. Table 13 Settings and Corresponding Commands Operation Command... -
Page 61: Markings Used In This Manual
Entering/Exiting the Command Mode Before any commands can be given to the FD12P, the communication line in the FD12P has to be assigned to the operator. Otherwise, it is assigned to automatic messages or polled communication. The user assigns the command mode with the OPEN command. -
Page 62: Close Command
User's Guide _______________________________________________________________________ The FD12P answers LINE OPENED FOR OPERATOR COMMANDS If no input is given within 60 seconds, the FD12P closes the line automatically. CLOSE Command Line can be released to automatic data messages by typing ↵ ↵ ↵ ↵... -
Page 63: Message Types
The length of the status message depends on the possible alarm and warning states. The FD12P adds frame strings to the polled and automatic messages. The content of the frame strings is presented in the following: !FD id"message body#-*... -
Page 64: Message 0
User's Guide _______________________________________________________________________ NOTE The contents of messages 0, 1, 2, 5, 6, and 7 are illustrated as follows: <- The first row is the output. 6800 110.96 ↓↓ ↓ ↓ ì ì ì ì Field --------- offset frequency í í í í descriptions ------- one minute average visibility î... -
Page 65: Message 2
0#-* 01234567890123456789012345678901234567890123456789012345 Message 3 Message 3 is the same as the status message obtained by using the STA command. Refer to Table 22 on page 86 for possible error texts. FD12P STATUS SIGNAL 0.39 OFFSET 126.83 DRIFT 0.14 REC. BACKSCATTER 1281 CHANGE TR. -
Page 66: Message 4
-- S, status heading ------ background luminance value cd/m2(option) -- B, background luminance heading ------- (contamination) compensated visibility (reserved, not supported by FD12P) --- CV, compensated visibility heading ------- non-compensated visibility m -- V, visibility heading -- unit ID (one character only) -- ID, start indicator - <STX>... -
Page 67: Table 16 Transmitter Status Correspondence Between Mitras And Fd12P
Chapter 4 _________________________________________________________________ Operation The status bits emulate the MITRAS status as shown in Table 16 and Table 17 below. Table 16 Transmitter Status Correspondence between MITRAS and FD12P MITRAS FD12P MEAS MODE ECON MODE OPTICAL SURFACE TRB warning or alarm... -
Page 68: Message 7
The background luminance value displays the measured luminance in cd/m², if the Vaisala LM11 Background Luminance Meter is attached to the FD12P (option FD12PLM11). If a day/night switch is connected to the processor board, the background luminance value displays the switch state (1 = day, 0 = night). -
Page 69: Message Polling
Selected in the configuration message_ Optional number If only one FD12P unit in on the line and no id is set, the command format is the following: <ENQ> FD <CR> When the FD12P unit number two (id = 2) is polled for message number 3, the command format is the following: <ENQ>... -
Page 70: Fd12P Command Set
<SOH> (01 hex) character. The FD12P waits about 100 ms after turning the carrier on before it starts to send the message. When the FD12P has sent the message, it turns the carrier off. This will also generate additional characters, which have to be ignored by the host. -
Page 71: Mes Command
↵ MES 2 AMES Command The AMES command defines the message, which the FD12P transmits as the automatic message or as the default polled message. Messages can also be displayed by the MES command, described in MES Command on page 71. -
Page 72: Ames Message_Number Message_Interval
User's Guide _______________________________________________________________________ The format of the AMES command is the following: AMES Message_number Message_interval where Message_number - The valid range is 0 to 7. - Selects the corresponding message. Any negative message number is converted to 0. - The message number is also the default number for the MES command and polling. -
Page 73: Weather Related Commands
The command asks for one parameter at a time, showing the parameter name and the current setting. Accept the current value by pressing ENTER. You can give a new value by typing the value before pressing ENTER. VAISALA ________________________________________________________________________ 73... -
Page 74: Precipitation Limit
Haze Limit The Haze limit parameter specifies the visibility threshold for reporting haze or mist. When the visibility is between 1000 m and the Haze limit, the FD12P will report either haze or mist depending on the air humidity. ______________________________________________________ M210296en-A... -
Page 75: Rain Intensity Scale
Drizzle Limit The Drizzle limit parameter refers to the maximum drop size (in FD12P internal units), which can be detected as drizzle. The typical value is 15, which has been found to be the optical signal from a 0.5 mm diameter droplet measured by typical FD12P hardware. The... -
Page 76: Heavy Drizzle Limit
The typical value for Snow limit is 5. A smaller value directs the FD12P to report more wet precipitation as snow. Heavy Snow Limit The Heavy snow limit parameter defines the minimum visibility (m) on a two-minute average in heavy snow. -
Page 77: Snow Pellets Limit
Chapter 4 _________________________________________________________________ Operation Snow Pellets Limit The Snow pellets limit parameter specifies the minimum particle size (in FD12P internal units), which is detected as snow pellets. (Additional internal criteria are used before the precipitation type is determined to be snow pellets.) -
Page 78: Clrs Command
This resetting can also be done in the protocol mode by the host computer, using the following command format: <ESC> FD id C <CR> Then the FD12P responds to the accepted command with the following ASCII character: <ACK> (06 hex) -
Page 79: System Configuration Commands
The current system parameters can be displayed by using the PAR, the System Parameters, command. When you type ↵ the system output is shown on the next page. SYSTEM PARAMETERS VAISALA FD12P V 1.83 1999-11-19 SN: 46401 ID STRING: AUTOMATIC MESSAGE 2 INTERVAL ALARM LIMIT 1 ALARM LIMIT 2 OFFSET REF 130.50... -
Page 80: Conf Command
User's Guide _______________________________________________________________________ CONF Command The configuration command, CONF, is used to set or update system parameters and to adjust certain calibrations, reference values, and limits. You can limit the use of this command by protecting it with a password. New parameter values are saved in the non-volatile memory (EEPROM). - Page 81 The system asks the following: UPDATE CONFIGURATION PARAMETERS UNIT ID (2 CHAR)( 1) If the FD12P unit is named by one- or two-character ID codes, the OPEN and POLLING commands use it as a parameter. The ID code is VAISALA ________________________________________________________________________ 81...
- Page 82 The new value is used to correct the internal TE scaling factor. The TE temperature is used as a backup in FD12P. The temperature is used in the visibility measurement to control the precipitation effect correction algorithm. Snow and rain have a different kind of effect on the scattering signal when it is used for the visibility calculation.
- Page 83 0 as LN(0) is not defined. ANALOG OUTPUT MODE 0 = LINEAR 1 = LN ( 0) ANALOG OUTPUT RANGE MAX VISIBILITY 10000) MIN VISIBILITY END OF CONFIGURATION VAISALA ________________________________________________________________________ 83...
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Page 84: Baud Command
BLSC Command The Vaisala LM11 Background Luminance sensor can be connected to the FD12P for ambient light measurement. Each LM11 sensor has an individual scaling coefficient, which is defined at the factory. The scaling coefficient is written on a label in the LM11 sensor. This coefficient should be configured to the FD12P for correct scaling of the measured background luminance values. -
Page 85: Maintenance Commands
10.400 If a day/night switch is connected to the serial line control input on the FDP12 processor board, the FD12P can read the switch state and report it as a background luminance value of 1 (day) or 0 (night). The FD12P firmware will read the switch if the background luminance scaling factor is set to 0. -
Page 86: Table 22 Hardware Error Texts
User's Guide _______________________________________________________________________ SIGNAL 0.39 OFFSET 126.83 DRIFT 0.14 REC. BACKSCATTER 1281 CHANGE TR. BACKSCATTER 10.3 CHANGE 19.4 LEDI 15.1 -15.0 BGND -0.1 AMBL 0.1 DUTY DRI21 MEASUREMENTS 1.8 DRD INST 811 DRY 915.6 HARDWARE : An asterisk (*) before a value indicates an exceeded limit. In the end, there are verbal comments on the combined errors detected. -
Page 87: Cal Command
CAL 985 The calibrator signal value is printed on the labels of the glass plates. Typically, the signal is close to 1000 Hz. The FD12P calculates a new scaling factor and stores it in the non-volatile memory (EEPROM). Refer to section Calibration on page 119 for instructions. -
Page 88: Clean Command
This command is given during maintenance procedures after cleaning the lenses or after replacing the transmitter or receiver board. When you type ↵ ↵ ↵ ↵ CLEAN the FD12P output is as follows: CLEAN REFERENCES TRANSMITTER 12.0 RECEIVER 1402... -
Page 89: Chec Command
ESC key. The first line is a title line with the signal names. DRY and WET Commands The DRY and WET commands are used to check and adjust the operation of the Rain Detector DRD12 analog signal measurement. VAISALA ________________________________________________________________________ 89... -
Page 90: An Command
User's Guide _______________________________________________________________________ The DRY command is used to set the dry signal end of the DRD12 signal normalization calculation. When you type ↵ ↵ ↵ ↵ the output is, for example, the following: DRD DRY OFFSET 915.6 The DRY OFFSET value must be between 850 and 980 when the DRD12 hardware operates normally. -
Page 91: Analog Output Commands
In linear mode: Scale 1 = bits16mA / (maximum vis - minimum vis) In logarithmic mode: Scale 1 = (ln(max vis) - ln(min vis)) / bits16mA bits16mA = (3200 / (high current - low current)) × 16 VAISALA ________________________________________________________________________ 91... -
Page 92: Data Scaling
User's Guide _______________________________________________________________________ When you type ↵ ↵ ↵ ↵ ACAL the command gives, for example, the following output: MEASURED CURRENT (mA) 22.16 MEASURED CURRENT (mA) 4.52 Data Scaling The FD12 scales the visibility value to a binary number for the DAC ( = DACBITS) so that the minimum visibility corresponds to the 4 mA-calibrated value and maximum visibility to the 20 mA- calibrated value. -
Page 93: Other Commands
The DATE command is used to display the current date. Type ↵ ↵ ↵ ↵ DATE To set a new system date, use the command: DATE yyyy mm dd ↵ ↵ ↵ ↵ where yyyy = Year mm = Month VAISALA ________________________________________________________________________ 93... -
Page 94: Reset Command
User's Guide _______________________________________________________________________ RESET Command The RESET command makes the hardware reset by the watchdog circuitry. The command format is the following: ↵ ↵ ↵ ↵ RESET ______________________________________________________ M210296en-A... -
Page 95: Functional Description
As the extra parameter, the FD12P measures an estimate of the water content of precipitation with the DRD12 rain detector. In rain, the water equivalent and the volume are equal. -
Page 96: Optical Measurement
The FD12P has a small sample volume of about 0.1 liters (see Figure 21 above). This enables independent particles to be measured even at quite heavy precipitation intensities. -
Page 97: Figure 22 Fdt12B Transmitter Block Diagram
A reset pulse (RES) from the FDR12 Receiver synchronizes the IR- LED timing with the receiver's lock-in amplifier. The CPU can also delay the transmitter firing for a special out-of-phase measurement. This feature is used in measuring the internal noise level (offset) of the circuitry. VAISALA ________________________________________________________________________ 97... -
Page 98: Fdr12 Receiver Unit
User's Guide _______________________________________________________________________ An extra photodiode measures the light scattered backwards from the lens, other objects, or contaminants. This signal as well as several internal signals are monitored via MUX-line. The CPU board supplies only one voltage Vb = 10 - 13 V for both the transmitter and receiver. -
Page 99: Additional Measurements
Additional Measurements General The FD12P includes the DRD12 Rain Detector for estimating the water content of precipitation and the DTS14B Temperature Sensor for measuring the sensor crossarm temperature (TS). Both additional sensors are measured using the DRI21 Interface Board, which is coupled on the FD12P PICOBUS. -
Page 100: Drd12 Rain Detector
User's Guide _______________________________________________________________________ 9807-031 Figure 24 DRI21 Block Diagram in the FD12P Application DRD12 Rain Detector The DRD12 analog signal is proportional to the water amount on the sensing surfaces. Water on the DRD12 changes the capacitance of the sensor elements. The capacitance of the elements controls the output frequency of an oscillator. -
Page 101: Dts14B Temperature Sensor
The temperature (TS) is used to select the default precipitation type and to separate freezing rain from non-freezing rain. FDP12 Control Unit The FDP12 Control Unit consists of the microprocessor, communication interface, memory, frequency measurement circuitry, watchdog, monitoring circuitry, and digital-to-analog converter. VAISALA _______________________________________________________________________ 101... -
Page 102: Figure 26 Fdp12 Control Unit Block Diagram
FDP12 takes care of communication through the RS-232 serial port. The alternative RS-485 interface allows a simple method for multiple FD12P Weather Sensors to communicate on the same line. The PICOBUS interface facilitates a connection to a number of Vaisala peripheral units. The memory includes a 512-kbit EEPROM for program code and a 256- kbit static RAM for data and working parameters. -
Page 103: Measurement Signal Processing
Measurement Signal Processing Optical Signal Processing The software running in the FDP12 CPU controls the measurement hardware and reads the data samples. The FD12P measures in 15- second cycles as follows: - 10 s signal frequency and analog monitoring voltages are... -
Page 104: Drd12 Signal Processing
User's Guide _______________________________________________________________________ 9807-034 Figure 28 Optical Signal Amplitude Distribution (in Rain) DRD12 Signal Processing The DRD12 output voltage is measured once a second by the DRI21 interface board. With dry surfaces, the voltage is approximately 3 V and drops when the sensing elements become wet (Figure 29 below). 0110-186 Figure 29 DRD12 Surface Signal (Heavy Rain Beginning) -
Page 105: Algorithm Description
FD12P. The estimated humidity is used to separate between haze and mist. As the FD12P can detect the beginning of precipitation from the optical signal, the DRD12 heating can be turned off when there is no precipitation. -
Page 106: Detecting Precipitation
The precipitation ending is detected when the summed optical signal amplitudes decrease below another, lower threshold value. The summing interval depends on the detected precipitation intensity. Typically, the FD12P will detect precipitation ending within a few minutes but in low intensity precipitation the detection time may reach 10 minutes. -
Page 107: Precipitation Accumulation
In liquid precipitation the optical intensity is reported as such. When frozen precipitation is detected, the FD12P multiplies the optical intensity with a scaling factor to get an estimate of the water equivalent intensity. This scaling factor is calculated from the DRD12 and optical intensities. -
Page 108: Present Weather
Snow limit value. - Rain&snow and Rain when the intensity ratio is between one and Snow limit. If this temperature limit is set higher (towards +8 °C), the FD12P reports snow and rain&snow more often (but not above this limit temperature). -
Page 109: Liquid Precipitation
0 °C (TS), it is indicated as freezing rain or freezing drizzle (ZR, ZL). NOTE The FD12P freezing precipitation detection is based on the practical definition of "rain (or drizzle) freezing on surfaces", not on detecting supercooled water. -
Page 110: Frozen Precipitation
(stratus cloud). The FD12P reports the instant weather code by the size information only. The 15-minute weather code in the FD12P report is drizzle, when at least ten minutes of only drizzle precipitation has been observed. The one-hour code is generated by the majority principle. -
Page 111: Mixed Precipitation
Chapter 5 _______________________________________________________ Functional Description Mixed Precipitation The FD12P reports either rain and snow (WMO codes 67 and 68) or ice pellets (WMO codes 74, 75, and 76) when the intensity ratio is between one and Snow limit. The intensity is determined by estimating the water equivalent intensity and using the rain intensity limits. -
Page 112: Haze And Mist
(10) is used instead of HAZE. If the estimated humidity is low and the visibility during the 10-minute average is less than 1000 m, then code 05 (smoke, dust, or sand) is used. When visibility increases above Haze limit × 1.2, the FD12P will report CLEAR (code 00). Weather Classes The weather classes are continuous, showers, or intermittent. -
Page 113: Weather Code Selection
W and W are for weather after the last main observation (00, 06 ... ). The FD12P codes are directly intended to be used for W . The automactic weather station will generate W The (automatic) weather station that uses the FD12P data, can in many cases also use other weather parameters to select from the three codes from the FD12P or even correct them. -
Page 114: Internal Monitoring
Normal operation is indicated by the green LED blinking once every second. The yellow LED is on when the FD12P measures the visibility signal. _____________________________________________________ M210296en-A... -
Page 115: Memory Tests
Memory Tests After resetting, the FD12P tests and clears its SRAM data memory. It indicates an error by the red LED blinking. After 50 blinks, the FD12P tries to start the program anyway. Usually, this causes a watchdog reset, if the SRAM is really faulty. -
Page 116: Contamination Monitoring
User's Guide _______________________________________________________________________ Contamination Monitoring The FD12P monitors both the transmitter and receiver contamination by measuring the backscattered signal. The CLEAN command is used to set the clean reference values of the backscatter signals. The deviation of the backscatter signal from the clean values is proportional to the contamination on the lenses. -
Page 117: Chapter 6 Maintenance
MAINTENANCE This chapter describes the overall maintenance of the product. General No initial calibration of the FD12P is needed because the sensor has been calibrated at the factory. The periodic maintenance of the FD12P Weather Sensor includes: - Cleaning the transmitter and receiver lenses and hoods. -
Page 118: Cleaning
User's Guide _______________________________________________________________________ Cleaning Cleaning Lenses and Hoods The lenses of the FD12P transmitter and receiver units must be relatively clean to obtain reliable results. Dirty lenses give too high visibility values. Clean the lenses every six months or more often depending on the conditions (for example, if there are roads nearby). -
Page 119: Calibration
Calibration General The FD12P has been calibrated at the factory. Normally, the FD12P needs no recalibration as long as the circuit boards are not changed or there is no call for warnings and alarms. The circuit boards need no hardware calibration. -
Page 120: Calibration Check Procedure
User's Guide _______________________________________________________________________ When the calibrator is used in precipitation, the error will be proportional to the area of the scatter plates, which are covered by droplets. Make sure that this area is negligible compared with the total area. Bright sunlight shining on the calibrator plates will increase noise in the scatter measurement and make the CHEC command output less stable. - Page 121 The signal value must be close to the one printed on the plates. If the difference is less than 3 %, the calibration is correct. If not, continue with the calibration procedure. Terminate the CHEC command by pressing the ESC key. VAISALA _______________________________________________________________________ 121...
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Page 122: Figure 31 Assembling The Fda13 Calibrator
User's Guide _______________________________________________________________________ 0201-087 Figure 31 Assembling the FDA13 Calibrator _____________________________________________________ M210296en-A... -
Page 123: Calibration Procedure
CAL 985 The calibrator signal value is printed on the labels of the glass plates. Typically the signal is close to 1000 Hz. The FD12P calculates a new scaling factor and stores it in the non-volatile memory (EEPROM). Type... -
Page 124: Calibrating The Dts14B Temperature Sensor
User's Guide _______________________________________________________________________ Calibrating the DTS14B Temperature Sensor Calibration of the DTS14 Temperature Sensor is recommended to be carried out once a year. For the sensor accuracy, only 0 °C temperature is important as this temperature is used to identify freezing rain. -
Page 125: Figure 32 Dts14 Sensor Holder Assembly To Mast
Chapter 6 _______________________________________________________________Maintenance 0201-088 Figure 32 DTS14 Sensor Holder Assembly to Mast The following numbers refer to Figure 32 above: Sensor holder DTS14 Fixing screw VAISALA _______________________________________________________________________ 125... -
Page 126: Removing And Replacing
FDT12B Transmitter, FDR12 Receiver, and the Rain Detector DRD12. You can remove the units when you suspect that malfunction of the FD12P is caused by faults in the optical units or the rain detector. Removing and Replacing Optical Units WARNING The equipment contains dangerous voltage of 230 VAC. -
Page 127: Figure 33 Removing The Optical Units
Removing the Optical Units The following numbers are related to Figure 33 above: Hood tube FDT12B transmitter/FDR12 receiver Round flange Cover 4 screws (M6 x 16 DIN7991) 5 mm Allen key 3 locking bolts Connector Ribbon cable VAISALA _______________________________________________________________________ 127... -
Page 128: Figure 34 Replacing The Optical Units
User's Guide _______________________________________________________________________ To replace the optical unit, do the following: Insert the FDT12B Transmitter/ FDR12 Receiver unit into the hood. Note that the position of the unit is correct, see Figure 34 below. Connect the ribbon cable connector with the optical unit. Tighten the three-hexagon socket locking bolts with a 5-mm, T- handle Allen key. -
Page 129: Removing And Replacing The Drd12 Rain Detector
Loosen the hexagon nut of the cable feedthrough and detach the wires from the screw terminal inside the DRD12 unit. Then pull the DRD12 cable out of the unit. Deliver the entire DRD12 unit to Vaisala. 0110-189 Figure 35 Removing the DRD12 Rain Detector... -
Page 130: Calibrating Fd12P Weather Sensor After Unit Replacement
Calibrating FD12P Weather Sensor after Unit Replacement The hardware of FD12P electronics unit has been checked and tuned at the factory. All adjustments specific to a complete sensor are made in the software. The sensor stores the calibration factors and several internal monitoring values in the EEPROM memory on the processor board. -
Page 131: Table 24 Parameters For Optical Measurement
Note! Scaling coefficient can be left unchanged without practically any harmful effects. DTS14 Temperature Update offset value. TCAL TS Sensor DRI21 Sensor Update temperature offset. TCAL TS Interface FDP12 Processor All of the above (including Board WET). VAISALA _______________________________________________________________________ 131... -
Page 132: Table 28 Parameters And Commands
User's Guide _______________________________________________________________________ The parameters controlling the operation mode (automatic or polling), message type, and weather type decision thresholds are also stored in the EEPROM. If the processor board is replaced, these parameters should also be checked and updated. The parameters and commands are listed in Table 28 on page 132. -
Page 133: Chapter 7 Troubleshooting
Open the command mode and check the status information with the STA command or poll Message 3 for the same information. See section STA Command on page 85 for descriptions of the status message errors and warnings. Check the monitoring values against the internal monitoring limits. VAISALA _______________________________________________________________________ 133... -
Page 134: Message Missing
User's Guide _______________________________________________________________________ Message Missing Check that your terminal has the correct settings. The FD12P default is 300 bit 7E1. If the settings are not correct, you can - Change the baud rate, for example, to 300 baud. - Check that you have seven data bits, even parity, one stop bit. -
Page 135: Visibility Value Is Missing
Chapter 7 ____________________________________________________________ Troubleshooting Visibility Value is Missing The FD12P control electronics is probably working. Check the following: - Check the status information with the STA command (see section STA Command on page 85). If there are active hardware alarms, visibility values are removed from data message. -
Page 136: Visibility Is Constantly Too Low
DRD12 detection is used in cross-checking the optical detection and false detection can only be caused by problems in both measurements. Check that there are no flashing lights close to the FD12P. Flashing lights may cause the FD12P to detect peaks in the optical signal. -
Page 137: Have Jumper Settings Been Changed
- If possible, check the accumulated water sum against a reference rain gauge This will indicate how close Rain intensity scale is to the optimal value. Decrease the scaling factor if the FD12P rain amount is too high. - Otherwise, increase DRD scale. Have Jumper Settings Been... -
Page 138: Table 29 Values For Internal Monitoring
<-9 V The sun is shining directly or from reflecting 2. Check orientation surface (water, window, of FD12P. etc.) to the receiver. 0.8 V +0.6 V/ <0.2 V No heating current is 1. Check that the Lens heater. - Page 139 Move your hand in the proportional to sampling volume, and visibility. you can check the operation of FD12P. If no sound or no Freq. Corr. Sound changes in range change, check other Visibility 130 ... 10000 Hz...
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Page 140: Getting Help
+1 V >+1 V cable. for the transducer, i.e., voltage loss in transducer cable. Getting Help For technical support or comments on the manual, contact the Vaisala technical support: E-mail helpdesk@vaisala.com Telephone +358 9 8949 2789 +358 9 8949 2790... - Page 141 Pack the faulty product using an ESD protection bag of good quality with proper cushioning material in a strong box of adequate size. Please include the Problem Report in the same box. Send the box to: Vaisala Oyj SWD Service Vanha Nurmijärventie 21 FIN-01670 Vantaa Finland VAISALA _______________________________________________________________________ 141...
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Page 143: Nws And Wmo Codes Used In Fd12P
Appendix A _________________________________________NWS and WMO Codes Used in FD12P APPENDIX A NWS AND WMO CODES USED IN FD12P The NWS Codes Table 30 Internal Weather Types, NWS Code Weather Type Code No precipitation Precipitation Drizzle Rain Snow Ice pellets Sleet... - Page 144 User's Guide _______________________________________________________________________ Code figures 20 to 25 are used, if precipitation or fog was observed during the preceding hour but not at the time of observation. Table 32 WMO SYNOP Codes (4680, W Code Weather type PRECIPITATION Drizzle (not freezing) or snow grains Rain (not freezing) Snow Freezing rain or freezing drizzle...
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Page 145: Table 34 Wmo Code Table 4678. Codes Used By Fd12P
Appendix A _________________________________________NWS and WMO Codes Used in FD12P Code Weather type SHOWERS OR INTERMITTENT PRECIPITATION Rain showers, light Rain showers, moderate Rain showers, heavy Rain showers, violent (>32 mm/h) Snow showers. light Snow showers. moderate Snow showers. heavy Showers of hail, with or without rain or rain and snow mixed, not... - Page 146 User's Guide _______________________________________________________________________ This page intentionally left blank. _____________________________________________________ M210296en-A...
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Page 147: Jumper Settings And Internal Wiring
Appendix B ___________________________________________ Jumper Settings and Internal Wiring APPENDIX B JUMPER SETTINGS AND INTERNAL WIRING See Figure 36 on page 148. VAISALA _______________________________________________________________________ 147... -
Page 148: Figure 36 Basic Electronics Enclosure Wiring
User's Guide _______________________________________________________________________ 020-090 Figure 36 Basic Electronics Enclosure Wiring _____________________________________________________ M210296en-A... -
Page 149: Cpu Board
20 ... 24 VAC/4A for hood heaters, (pin 4: alternative status relay input) DC output connector pin 6: GND, pin 4: +11..12 V DRI21 Interface Board Table 38 DRI21 Interface Board Jumpers Jumpers Description PICOBUS address selection VAISALA _______________________________________________________________________ 149... -
Page 150: Table 39 Dri21 Interface Board Connectors
User's Guide _______________________________________________________________________ Table 39 DRI21 Interface Board Connectors Connectors Description sensor interface auxiliary board connector PICOBUS connector Table 40 Electronics Enclosure/Transducer Cable Signals Description Signal name Enclosure Crossarm Color FDP12 FDT/FD DRD12 plug R cable cable Ground X15/1 1/BRN Supply voltage X15/2 2/RED... -
Page 151: Transmitter And Receiver Test Points
Appendix C __________________________________________ Transmitter and Receiver Test Points APPENDIX C TRANSMITTER AND RECEIVER TEST POINTS There are some test points (TP) on the FD12P circuit boards for testing. They are as follows: Table 41 Transmitter Test Points Test Point Description Reference voltage +2.5 V, ±1 %... -
Page 152: Figure 38 Test Points, Receiver
User's Guide _______________________________________________________________________ Table 42 Receiver Test Points Test Points Description Synchronizing pulse for factory tests Reference voltage -2.5 V, ±1 % +5 V Measurement signal after high-pass filter P15: +15 V, ±1 V M15: -15 V, ±1 V Measurement signal after 2-stage amplifier (AC) Measurement signal 0 …... -
Page 153: Index
Analog output commands 130, 149 ACAL Analog Output Commands Analog Transmission DAC command Applications DATE Assembling the FD12P Detecting Precipitation Automatic Message Sending DRD12 Rain Detector DRD12 Signal Processing DRI21 Interface Board Basic Wiring DTS14 Temperature Sensor 18, 124, 131... - Page 154 Modem DMX21 TIME 21, 26, 30, 48, 95, 105, 106 Mounting to an Existing Surface Mounting When Casting the Pad Unloading and Unpacking User Commands in Normal Operation Using FD12P visibility algorithm ON/OFF switch 20, 45 OPEN Operating Principle warnings...
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