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SWS-200 User Manual

1. 55 Re calibration zone end bte do DL cr b eb dee iia 59 MOUINTIN cse SEE INSTALLATION O OPTIONAL ACCESSORIES semer hi dece de re Me ete Ddug hentai dd cdd 2 64 Ambient Light Sensor seen 9 Calibration Kit Mains Adaptor Transit case ORIENTATION OESENSOR 4 221 5 3 3 0 pte dne eb Hades Ue MR EUR dre ebd pae deed od ill te EE MR PERPE RUE ge 24 P PINCONNEGTIONS 3 0 ioci is eddie a eg M dpa ee 4 Index 83 Biral Index CG _ a Section 7 Connections for 0 4 20mA analogue output seen 8 Connections for Power Supply Connections for Relay Connections for RS232 or RS422 POWER REQUIREMENTS 54 den reto so ret ee e tee Pared Eten rt dd ipeo re E ea Meme ees o Cre eva Pao E ba DRE VER Papa PRECIPITATION AMOUNT CALIBRATION PRESENT WEATHER yc tiree O R D PD FA SETA TERN EET EROR TERTII Fy ASEE IPSE ERE seed Present weather codes in SWS 100 data message ooooociccocccocicconconcononcnnnononncononocnnononnnononn cn ncnncnnonn cn noncannnnnns Present weather codes in SWS 200 data message T Present weather codes in SWS 250 data message ssssssssssseeeeeee HELI eene ene PRODUCT OVERVIEW i55 e risdecsdevess etere bene munie inde e re RI poer TYF ota enceintes eek re TD sion decana PROTECTIVE EARTH BONDING ui ee Uno e d bete tes et e debite rete poe eerie papi R RELAYS Pin Conec
2. Sensor Set up 1 SENSOR SET UP The format of this section is such that it logically follows these recommended procedural steps Step 1 Unpack equipment and ensure that all required parts are supplied and identified Step 2 Make electrical connection as required for testing and configuration Step 3 Power up and test equipment on bench Step 4 Configure equipment as required for site installation Step 5 Installation including siting considerations height orientation mounting and electrical grounding Step 6 Carry out commissioning test procedure NOTE Many of the tests specified within this manual require the use of a PC or equivalent To achieve the two way serial communication required Biral recommends the use of a PC running the Biral Sensor Interface Software If this software is not available use a terminal program for example Windows Hyper Terminal M The Biral Sensor Interface Software is available from our website www Biral com or contact Biral at Info Biral com Sensor Set up 1 Biral Sensor Set up Section 1 1 4 STEP 1 Unpacking the Sensor The sensor is packed in a foam filled shipping container and is fully assembled ready for usc The sensor is delivered with U bolts for pole mounting SWS sensor in 2 off ferrites for cable foam filled EMC protection packaging NS Documentation example shows SWS 200 Other optional items you may have ordered F
3. Function Details Interface Type RS232C Full Duplex User Selectable RS422 RS485 Communication Parameters Function Details Baud Rates User selectable 1200 Baud to 57K6 Baud Default 9600 Baud Data Bits 8 Parity None Stop Bits 1 Flow Control None Message Termination lt CR LF gt Message Checksum Selectable sum modulo 128 for RS232 422 LRC for RS485 Reporting Interval Programmable Response to poll or Automatic at programmable intervals 10 seconds to 5 minutes 1 minute typical Message Content Instrument Identification Number Programmable Reporting Interval seconds Meteorological Optical Range Kilometres Precipitation Type Obstruction to Vision Fog Haze None Precipitation Amount One Minute Interval Temperature Remote Self Test amp Monitoring Flags Date and time tags Table 6 11 Digital communication interface specifications 78 Digital Communication Interface Biral Section 6 6 9 Analog Outputs ST Product Overview These are available only on models SWS 050T SWS 100 and SWS 200 Function Details Voltage 0 to 10 Volts out Equivalent to 0 to MORyAx 4 to 20 mA Equivalent to 0 to MORyAx option Current 0 to 20 mA Equivalent to 0 to MORmax option NOT SWS 050T Table 6 12 Analog output specification 6 10 Relay Outputs These are available only on models SWS 050T SWS 1
4. 00D FF Recommendations When using the sensor on an RS485 network it is recommended that the sensor be set up in polled mode Automatic message transmission disabled rather than transmitting a data message automatically See paragraph 1 4 7 for full instructions for setting this configuration NOTE When RS485 communications are enabled the sensor will not output the Biral Sensor Startup message on power up and reset Automatic message setting The sensor can be set to send a data message automatically after each data collection period or to send a data message only when requested polled sensor The default setting is for automatic data transmission To check which method 1s programmed send the message OSAM The sensor will send the reply 00 Automatic message transmission disabled 01 Automatic message transmission enabled To set the sensor to the required automatic message setting send the message STEP 4 Configuration Options 19 Sensor Setup Section 1 20 1 4 8 1 4 9 OSAMx Where x is 0 Automatic message transmission disabled 1 Automatic message transmission enabled The sensor will respond with OK Optional hood heater operating setting The sensor can be set to have the hood heaters disabled or for them to work automatically The default setting for sensors with fitted hood heaters is for automatic hood heater operation To check which configuration is programmed send the
5. 1 Relay for precipitation or visibility This model has an extra backscatter receiver for SWS 250 Rain rate Snowfall rate Precipitation accumulation Biral Visibility Precipitation type identification Rain rate Snowfall rate Precipitation accumulation This model will additionally report 39 weather codes from WMO Code Table 4680 mcluding Past weather Freezing Fog Ice Pellets Biral PATENT COVERAGE The Present Weather Measurement Techniques are protected by the following Patents U S Patent No 4 613 938 Canadian Patent No 1 229 240 German Patent No 3 590 723 RoHS compliant Thank you for choosing Biral as your supplier of present weather sensors A great deal of time has been invested at Biral to offer the best combination of sensor performance and value and almost three decades of experience and knowledge have been incorporated into the SWS series We are confident that they will provide you with many years of accurate operation Features of the SWS Sensors full date time stamp in data string provided by the real time on board clock flexibility to connect to a wide range of data collection processing units with a choice of serial analogue and relay switching outputs easy installation due to its light weight and small footprint simple field calibration automatic sequence can be initiated after fitting calibration plaque Switching of external equip
6. Biral Section 6 Sensor Model Capability SWS 200 Visibility Precipitation type identification 1 Fault relay switch 1 Relay for visibility 1 Relay for precipitation or visibility This model has an extra backscatter receiver for Rain rate Snowfall rate Precipitation accumulation SWS 250 Visibility Precipitation type identification Rain rate Snowfall rate Precipitation accumulation This model will additionally report 39 weather codes from WMO Code Table 4680 mcluding Past weather Freezing Fog Ice Pellets Product Overview d Figure 6 2 SWS 200 and SWS 250 Capabilities Biral SWS 050 SWS 100 SWS 200 and SWS 250 Present Weather Sensors 63 Product Overview Section 6 64 6 1 1 6 1 3 Instrument Components Each sensor has been engineered and manufactured with high reliability components to provide accurate measurements under all weather conditions Its rugged aluminium powder coated construction is intended to serve you in the severest of environmental conditions throughout the long life of the instrument All models are shipped fully assembled Optional Items Hood Heaters standard on the SWS 050 and SWS 250 Heaters for the transmitter and receiver hoods These are to minimise any build up of ice within the optical paths They reguire 12W per hood supplied from an independent customer supplied source of 24 V either AC or DC Not to be confused with window heaters wh
7. SELECT REQUIRED BAUDRATE BY TYPING B NUMBER 1200 BAUD 2400 BAUD 1800 BAUD 9600 BAUD 19K2 BAUD 38K4 BAUD 57K6 BAUD SO En SA Select the baud rate to use for example to select 4800 baud the user would type B3 lt CRLF gt The user then receives a prompt to send an OK to the sensor at the new baud rate setting The new setting will only be accepted if the user manages to communicate with the sensor at the new baud rate within 60 seconds Otherwise the sensor will reset and continue operation with the original baud rate settings If an OK command is received at the new baud rate the sensor will update its settings and restart STEP 4 Configuration Options 21 Sensor Setup Section 1 22 1 4 11 Configuring the Relays To get the current relay configuration send the command JRO The sensor will respond with a number which corresponds to Value Description 0 No Relays Configured 1 Fault Relay Relay 1 triggered on visibility and Relay 2 triggered on precipitation 2 Fault Relay Relay 1 triggered on visibility and Relay 2 triggered on visibility 3 Fault Relay Relay 1 triggered on visibility and Relay 2 triggered on snow Table 1 7 Relay configuration The default value is set to 1 NOTE A response of 225 means that no relays are configured the same as 0 To change the configuration To change the relay configuration send the command JROx
8. The checksum character is positioned after the message and before the end characters lt crlf gt The checksum value is between 0 and 127 and is the sum modulo 128 the remainder after the sum is divided by 128 of all the ASCII values of the characters in the message except the end characters The checksum value is replaced by its bit wise complement if it happens to be any of the following ASCII 8 backspace ASCII 10 linefeed ASCII 13 carriage return ASCII 17 through ASCII 20 DC1 through DC4 or ASCII 33 exclamation point For Message Cl Cm lt cksum gt lt crlf gt The calculation is as follows lt cksum gt gt e wonias n 1 STEP 4 Configuration Options l Sensor Setup Section 1 16 IF lt cksum gt 8 THEN lt cksum gt 119 IF lt cksum gt 10 THEN lt cksum gt 117 IF lt cksum gt 13 THEN lt cksum gt 114 IF lt cksum gt 17 THEN lt cksum gt 110 IF lt cksum gt 18 THEN lt cksum gt 109 IF lt cksum gt 19 THEN lt cksum gt 108 IF lt cksum gt 20 THEN lt cksum gt 107 IF lt cksum gt 33 THEN lt cksum gt 94 1 44 Communications Configuration 1 4 5 The SWS sensor can use either RS232C or RS422 RS485 signal voltage levels The configuration of the sensor is selected by connecting to the appropriate terminal connections and setting the right jumper position see section 1 2 3 Connecting the power supply and signal cable If
9. connections are as follows Table 1 5 Pin Number Designation J12 J 0 4 20 mA Analogue Output MOR ve J12 K 0 4 20 mA Analogue Output MOR ve J12 L Not Used Table 1 5 Connections for 0 4 20mA analogue output This is a current sourced from the sensor It is derived from a 10 V digital to analogue output and is not isolated It should be terminated with a resistance not greater than 500 O to enable the maximum current of 20 mA to be available EMC Compliance In order to comply with the EMC reguirements in particular the susceptibility to conducted interference some of the leads connected to the sensor should be fitted with ferrites If this is not carried out the sensor could be affected by external electromagnetic fields The ferrites supplied with the unit should be clipped over the power and the signal leads between the gland and the connector blocks These are not reguired on the relay connections or on the hood heater supplies STEP 2 Electrical connections Biral Section 1 sensor set up 1 2 8 Biral Optional ALS 2 Connections Any of the SWS sensors can be supplied with an ambient light sensor model ALS 2 This sensor will be connected directly to the SWS sensor drawing its power from the sensor supply If required the ALS 2 will be fitted with hood heaters which will operate when the sensor hood heaters operate The output
10. 10m to 75km Visibility MOR Meteorological Optical Range reductions caused by fog haze smoke Meas res sand drizzle rain snow and general precipitation MOR 10km Better than 10 Measurement Accuracy MOR 20km Better than 15 MOR 30km Better than 20 Measurement Time Constant 30 seconds Stability of MOR Zero Setting Function Details Ambient Temperature Effects lt 0 02 km Long Term Drift lt 0 02 km Biral Sensor Specifications 75 Product Overview Section 6 Precipitation Measurements Not SWS 050 Function Details Detection Threshold Rain 0 01 5mm hr 0 0006 in hr Detection Threshold Snow H 0 Equivalent 0 0015mm hr 0 00006 in hr Rain Rate Maximum 500mm hr 20 in hr Maintenance Function Details MTBF Calculated 52 500 hrs 6 years Typical Calibration Check Interval 6 months Typical Clean Windows Interval 3 months Remote Self Test Monitoring Included Table 6 9 Sensor specifications 6 7 Instrument Characteristics Physical Function Details Scattering Angle 45 with 6 cone angle Sample Volume 400 cm Weight SWS 050 and SWS 100 SWS 200 and SWS 250 3 8Kg 4 3Kg including pole mounting kit 4 0Kg 4 5Kg including pole mounting kit Length 0 81 m Light Source Function Details Type IRED Central Wavelength 0 85u
11. 35 Freezing Fog 40 Indeterminate Precipitation Type 5 Slight Drizzle 52 Moderate Drizzle 53 Heavy Drizzle 57 Slight Drizzle and Rain 58 Moderate or Heavy Drizzle and Rain 61 Slight Rain 62 Moderate Rain 63 Heavy Rain 67 Slight Rain and Snow 68 Moderate or Heavy Rain and Snow 2 Standard Operating Data Message for the SWS 250 37 Biral Standard Operating Data Section 2 38 MESSAGE MEANING 71 Slight Snow 72 Moderate Snow 73 Heavy Snow 74 Slight Ice Pellets 75 Moderate Ice Pellets 76 Heavy Ice Pellets TI Snow Grains 78 Ice Crystals 81 Slight Rain Showers 82 Moderate Rain Showers 83 Heavy Rain Showers 85 Slight Snow Showers 86 Moderate Snow Showers 87 Heavy Snow Showers 89 Hail or Small Hail Graupel W Past Weather Typel SYNOP Code No past weather code 4 Fog or Thick Haze 5 Drizzle 6 Rain 7 Snow or Mixed rain amp snow 8 Showers W Past Weather Type2 SYNOP Code No past weather code 4 Fog or Thick Haze 5 Drizzle 6 Rain 7 Snow or Mixed rain amp snow 8 Showers DD Obstruction to Vision Message Blank No obstruction HZ Haze FG Fog EEEEE METAR Reporting Code See Section 2 4 1 FFF FFF Precipitation Rate mm hr GG GG KM Meteorological Optical Range km This is the instantaneous value HHH HH Total Exco km This is the averaged value OL Transmissometer equiva
12. 40 UP Indeterminate precipitation type 71 Precipitation Measurements Product Overview Section 6 Code METAR Description 5 DZ Drizzle not freezing slight 52 DZ Drizzle not freezing moderate 53 DZ Drizzle not freezing heavy 57 RADZ Drizzle and Rain slight 58 RADZ Drizzle and Rain moderate 58 RADZ Drizzle and Rain heavy 61 RA Rain not freezing slight 62 RA Rain not freezing moderate 63 RA Rain not freezing heavy 67 RASN Rain or Drizzle and Snow slight 68 RASN Rain or Drizzle and Snow moderate 68 RASN Rain or Drizzle and Snow heavy 71 SN Snow slight 72 SN Snow moderate 73 SN Snow heavy 74 PL Ice Pellets slight 75 PL Ice Pellets moderate 76 PL Ice Pellets heavy 77 SG Snow Grains 78 IC Ice Crystals 81 SHRA Rain Showers slight 82 SHRA Rain Showers moderate 83 SHRA Rain Showers heavy 85 SHSN Snow Showers slight 86 SHSN Snow Showers moderate 87 SHSN Snow Showers heavy 89 GR Hail 89 GS Small Hail Graupel 72 Table 6 8 SWS 250 WMO and METAR codes Precipitation Measurements Biral Section 6 Product Overview 6 5 4 Precipitation Recognition Matrix Biral The SWS series of sensors measure the amplitude and duration of the light pulse created by each precipitation particle as it falls through the sample volume Fro
13. Not used Table 3 3 Command T response 3 2 Sensor Responses RESPONSE MEANING BAD CMD The command was not understood by the sensor Check the text of the command and re send COMM ERR An error was detected in a character in the command Re send the command OK Command with no quantitative response was understood and executed TIMEOUT Command was sent with more than 10 seconds between characters Re send the command Command message was longer than 24 characters including end LOC LONG characters Check the text of the command and re send Biral Table 3 4 Sensor responses Sensor Responses 47 Maintenance Procedures Section 4 4 MAINTENANCE PROCEDURES The SWS series of sensors reguire very little maintenance The following sections detail the checks that are advisable to ensure continued good operation of the sensor The freguency of these checks depends upon the location and environmental conditions under which the sensor operates It is suggested that a general check plus window cleaning should take place typically at three monthly intervals This period may be increased or decreased dependent on the contamination determined during these inspections It is also recommended that a calibration check See Paragraph 5 1 is carried out at six monthly intervals to verify that the instrument is still continuing to perform within the specification Paragraph 4 2 Self Test Codes
14. Receiver test in progress Ired OFF 8 Sensor power reset since last R Command or any combination of these Field 3 Field 4 Field 5 Field 6 Field 7 Field 8 Field 9 Field 10 Field 11 Field 12 Field 13 Field 14 Field 15 Field 16 Field 17 46 2 450 2 550 Internal reference voltage 9 00 36 00 Supply voltage 11 5 14 0 Internal operating voltage 4 5 5 5 Internal operating voltage 11 5 14 0 Internal operating voltage 0 00 6 00 Forward scatter background brightness 0 00 6 00 Backscatter background brightness not SWS 050 or SWS 100 85 105 Transmitter power monitor 80 120 Forward receiver monitor option for SWS 100 and SWS 200 80 120 Back receiver monitor not SWS 050 or SWS 100 00 99 Transmitter window contamination 00 99 Forward receiver window contamination option for SWS 100 and SWS 200 00 99 Back receiver window contamination option for SWS 200 Temperature C 3300 4200 ADC interrupts per second Table 3 2 Command R response Sensor Commands Biral Section 3 Commands and Responses 3 1 3 Command T Send Instrument Times Message Response aaaa bbbb ccccc dddd aaaa Measurement interval for each operational data message 10 to 300 seconds default 60 bbbb Auxiliary measurement sample period time between measurement of peripheral signals during measurement interval 2 to 20 seconds default 5 Not used
15. dust and smoke Automated Measurements The present weather sensor utilises microprocessor technology to perform automatic visibility precipitation and temperature measurements The standard version is DC power operated however a mains converter is also available Patented techniques are employed to identify precipitation and to determine the presence of fog during episodes of precipitation 6 4 Visibility Measurements 66 6 4 1 Visibility Measurement Capability The visibility measurement capabilities of the sensor are summarised in Table 6 1 Determination of visual range is based on measurements of the atmospheric extinction coefficient EXCO Note that EXCO includes the attenuating effects of both suspended particles and precipitating particles Meteorological optical range MOR is determined by application of the standard relation MOR 3 00 EXCO Haze and fog are the two most common forms of obstructions to vision In the absence of precipitation the sensor determines the presence of haze or fog based on the MOR If the Present Weather Measurements Visibility Measurements Biral Section 6 Product Overview MOR is less than 1 km then fog 30 is indicated in the output message If the MOR is between 1 and 10 km then haze 04 is indicated in the output message If MOR is greater than 10 km no obstruction to vision is indicated Note Definitions of haze and fog may change dependent on the country of
16. see Figure 1 4 onto pins 1 and 2 for RS422 485 outputs and onto pins 2 and 3 to select RS232 outputs E D T Location of J7 PCB105281 Biral of zd Jumper on 1 amp 2 4 RS422 RS485 a Jumper on 2 amp 3 RS232 as in photograph Figure 1 4 Location of J7 RS232 422 485 select STEP 2 Electrical connections Biral Section Y gt Sensor set up 1 2 4 Connecting the relays Biral The unique ability to switch equipment using a visibility fog relay and or a precipitation rain snow relay is a feature of the SWS 100 and SWS 200 sensors For example you can set relays to automatically switch a speed reduction sign when visibility is below 100 m and then switch an additional danger of aguaplaning alert when it rains These connections are along the right hand side of the main circuit board at the gland end see Figure 1 5 They are a two part connector with pins in the circuit board and a removable plug for the connections It is advised that the plug is removed from the pins to enable the connections to be made to the cable before re connecting to the circuit board The connections are of a screw clamp type Contacts are defined here when relays are not energised RL2 NC RL2 COM RL2 NO RL1 NC RL1 COM RL1 NO FAULT NC FAULT COM FAULT NO NB The Fault relay operates in Failsafe mode ie is energised when there is no fault Figure 1 5 Relay Connections
17. where x is the value from the table above e g JRO2 Configures Relay 2 to be a second visibility relay To read the visibility Threshold levels To read the visibility threshold levels for Relay 1 and relay 2 send the following command RLn where n is the relay number either 1 or 2 The sensor will respond with the visibility threshold in km e g 10 00 km To change the visibility Threshold levels To change the visibility threshold levels for relay 1 or relay 2 send the following command RLn xx xx where n is the relay number either 1 or 2 and xx xx 1s the threshold level in km e g to set the threshold for relay 1 to 1km send the command RL1 1 00 STEP 4 Configuration Options 2 Biral Section 1 sensor set up 1 5 STEP 5 Installation 1 5 1 Biral Please consider the following factors when installing the sensor 1 Siting considerations 2 Height of the sensor above ground 3 Orientation of the sensor 4 Mounting the sensor 5 Electrical grounding Each of these factors is covered in more detail below Siting Considerations Pollutants Care should be taken to ensure that the sensor is situated away from any possible sources of pollutants for example car exhausts air conditioning outlets etc Particulates entering the sensor s sample volume will cause errors in the reported visibility measurements Reflected Light Car
18. A SUITABLE SWS CALIBRATION KIT AND PC ARE AVAILABLE 2 STEP 3 Equipment Test 11 Biral Sensor Set up Section 1 1 4 STEP 4 Configuration Options 12 1 4 1 There are a number of configuration options available for the user to select Three options date and time enable checksum enable and RS485 enable are set using a configuration byte of the Options Word detailed in sections 1 4 1 to 1 4 6 The remaining options are set using a configuration byte of the Operating State word These are set directly using commands starting with OS Each of these is detailed below in sections 1 4 7 to 1 4 9 Options Word The options word consists of two bytes Their current values can be determined by sending the OP command The reply will be as follows aaaaaaaa bbbbbbbb The upper byte aaaaaaaa is used to set internal operating parameters and should not be changed It will in general be 00000000 For the lower byte a value is entered as a binary number 1 s and 0 s Leading 0 s in the value need not be entered The value is stored in non volatile memory and the operating configuration when power is applied is that set by the last entered options word The definition of each bit of this byte is shown below Table 1 6 Note the first bit is bit 8 the last being bit 1 Each bit ofthe lower byte of the Options Word is defined as follows bbbbbbbb Bit 1 1 Add Date and Time to the start
19. SERERE H HEATERS Hood Heaters OU M D ss Connecting Power Supply etr beet it tee ever d A FD FT eb pede seek de ae des dede AU 5 Window heaters de mistets corde ctr ea id ar 48 I IDENTIFICATION NUMBER SENS Anne o ML INSTALLATION ee Electrical Grounding Height Above Ground Mountimgarnoiu n NN Os EIU ee sl O Siting Considerations TP RATING dd mere mn et dre fe me M MAINS ADAPTER ioo RH RERO MEN QI RP ID ME No E Eee 2 MAINTENANCE 48 General Checks Ae PCA m 48 Hood He ters i pire in ert d E e eb cei ada ME bond lasts ds dn iS een 48 Window Cie iii dec be eere a ede lr D C e eer ede 49 Self Test Codes ER User Confidence Checks uo nine Vo ever YNN CE SEEE EAE EKE REE iedabecyesh eva Ve Nd 51 MOR Calibration Check eu e eie toro dete ee or edd oves sa ade ete e de eon Dod eee 51 Receiver Background Brightness Check Window Monitor Checks MAINTENANCE SCHEDULS vit rete ceder edo ccties cendo eh do ren o do FIN dea do cites sedcheed deced deb de Sion cectudeasedebcchorstaendeddasencecs 76 MEASUREMENT PRINCIPLES Precipitation Recognition Matrix ses 74 METAR CODES eoa GG A e p CH e A EM rs esie e ERE EY EY ede eta need 40 41 72 METEOROLOGICAL OPTICAL RANGE 8 32 33 35 56 59 66 75 Calibration Check neii gi U
20. a variety of forms of precipitation dependent on the model selected Detection of the onset of precipitation in all the sensors is extremely sensitive being 0 00025 mm per minute for rain and approximately 0 000025 water equivalent mm per minute for frozen precipitation The actual limits of measurements are given in Table 6 2 Precipitation Measurements 67 Biral Product Overview Section 6 Function Details a Liquid Precipitation 0 00025 mm min 0 00001 in min minimum detection limit 0 015 mm hr 0 00060 in hr b Snow H50 Equivalent 0 000025 mm min 0 000001 in min minimum detection limit 0 0015 mm hr 0 000060 in hr Rain Up to 500 mm hr 20 in hr Precipitation Tate aain Snow Rain Equivalent up to 500 mm hr 20 in hr Table 6 2 Precipitation measurement limits 6 5 2 Precipitation Intensity Measurements In addition to the basic precipitation identification carried out in the SWS 100 SWS 200 and SWS 250 sensors the SWS 200 and SWS250 sensors are designed to measure the intensity of precipitation The intensity for each type of precipitation is classified as slight moderate of heavy Intensity of precipitation may be defined differently from one country to another In both the United Kingdom and the United States the intensity of precipitation is defined differently for drizzle and rain than for snow For drizzle and rain the intensity slight moderate
21. and heavy is based on the rate of fall of precipitation For snow the intensity is based on visual range In classifying precipitation intensity the sensor utilises the precise definitions given by the UK CAA CAP 746 document or in the US the Federal Meteorological Handbook These definitions are given in the tables below Table 6 3 and Table 6 4 Note If a sensor is intended for installation in a country where the definitions of precipitation intensity differ from the U K definitions it is possible for the sensor to be produced with the appropriate definitions installed BIRAL must be informed of this reguirement at the time of order UK Precipitation Definitions Drizzle Slight A trace to 0 26mm hour Moderate 0 26mm hour to 1 0 mm hour Heavy More than 1 0 mm hour 68 Precipitation Measurements Biral Section 6 Product Overview Rain Slight A trace to 1 0 mm hour Moderate Greater than 1 0 mm hour to 3 99 mm hour Heavy More than 3 99mm hour Snow Slight Visibility greater than 800m Moderate Visibility between 400 and 800 meters Heavy Visibility less than 400 meters Table 6 3 UK precipitation intensity definitions Based on CAA CAP 746 Reguirements for Meteorological Observations at Aerodromes US Precipitation Definitions Drizzle Slight A trace to 0 01 inches 0 3 mm hour Moderate 0 01 inche
22. data message from an SWS 200 sensor is as follows SWS200 001 060 00 13 KM 00 000 30 24 5 C 00 13 KM XOO Standard Operating Data Message for the SWS 200 z Biral Section 2 Standard Operating Data 2 4 Standard Operating Data Message for the SWS 250 The data message format is lt Date gt lt Time gt SWS250 NNN XXXX AA AA KM CC W W DD EEEEE FFF FFF GG GG KM HHH HH IILII 5JJJ JJ EKKK K C tLLLLL MMM NNNN OO OOOO PPP lt cs gt lt crlf gt MESSAGE MEANING lt Date gt Optional Date string in the form DD MM YY Time Optional Time string in the form HH MM SS SWS250 SWS250 message prefix NNN Instrument identification number set by the user XXXX Averaging time period in seconds AA AA KM Meteorological Optical Range km This is the averaged value CC Present weather codes From WMO Table 4680 Automatic Weather Station XX Not Ready first 5 minutes from restart 00 No significant weather observed 04 Haze or Smoke or Dust 20 Fog in last hour but not at time of observation 21 Precipitation in last hour but not at time of observation 22 Drizzle in last hour but not at time of observation 23 Rain in last hour but not at time of observation 24 Snow in last hour but not at time of observation 30 Fog 31 Fog in patches 32 Fog becoming thinner in last hour 33 Fog no appreciable change in last hour 34 Fog begun or becoming thicker in last hour
23. forward scatter receiver directly due South TRANSMITTER RECEIVER Figure 1 7 SWS 050 and SWS 100 Orientation TRANSMITTER RECEIVER Figure 1 8 SWS 200 and SWS 250 Orientation z STEP 5 Installation 75 Biral Sensor Setup Section 1 1 5 4 26 Mounting the Sensor On a pole Two stainless steel U bolts and saddles are provided for securing the sensor to the top of a mast see Figure 1 9 U Bolt Mounting Method The two V block saddles oppose the U bolt thus providing a secure grip on the mast The sensor can be mounted on a galvanised steel pipe or heavy walled aluminium tube with an outer diameter between 40 to 64 mm For mast diameters outside this range the U bolts provided will not be suitable Note pipe sizes often refer to their inside diameter some 60 mm ID pipe may be too large for the U bolts to fit around The sensor head should be mounted near the very top so that the mast will not interfere more than necessary with the free flow of fog or precipitation through the sample volume The flat stainless steel washers should be placed next to the powder coated surface of the mounting plate to prevent gouging by the lock washers as the nuts are tightened Figure 1 9 U Bolt Mounting Method STEP 5 Installation e Biral Section 1 sensor set up 1 5 5 Biral On a wall The sensor can be bolted directly to a flat su
24. of the data message 0 No Date and Time at the start of the data message Bit2 Not used Bit 3 0 Use temperature sensor value in PW determination This bit should not be changed Bit4 Not used Bit5 Not used Bit6 1 Add a checksum character to all sensor output messages 0 Don t add checksum character to all sensor output messages Bit 7 0 Adjust MOR values in data messages for measured transmitter window contamination This bit should not be changed Bit8 1 Use RS485 addressable Communications protocol 0 Do not use RS485 addressable Communications protocol Table 1 6 Options word lower byte STEP 4 Configuration Options e Biral Section 1 sensor set up 1 4 2 To set this word send command CO to enable changes and then command OPa0b0000c to set the Option Word as required For example send OP100000 to enable the checksum with no date and time stamp and not using RS485 leading 0 s are not necessary in this command Bit 1 Date and Time enable Bit6 Checksum enable and Bit 8 RS485 enable are the only bits which may be set to 1by the user All other bits MUST be left at 0 for correct sensor operation The functions controlled by this byte are detailed in sections 1 4 2 to 1 4 6 The Default setting 00000000 Date and Time Stamp in data string By default the date and time stamp is not included at the start of the data string This is co
25. scatter calibration value of the plaque and the response to the BB command is within 5 of the back scatter calibration value of the plaque then the sensor is within its calibration limits The sensor can be returned to its operational configuration with confidence Sensor Re calibration Biral Section 5 Calibration Procedures 5 3 Precipitation Amount Calibration Biral Note All commands should be terminated with lt Carriage Return gt and lt Line Feed gt lt crlf gt see Paragraph 1 3 This section is only applicable to models SWS 200 and SWS 250 This process provides for adjusting the calibration factor of the sensor precipitation measurement The amount of adjustment to this factor is determined by making an independent measurement of the liguid accumulation over several rain episodes and comparing the accumulation reported by the sensor to this independently measured accumulation The value to be entered to adjust the precipitation amount factor is calculated as follows Value entered _ Desired precipitation accumulation 100 Sensor s reported precipitation accumulation EXAMPLE Over several rainstorms a reference sensor measures an accumulation of 225 millimetres The SWS sensor reported an accumulation of 244 millimetres To adjust the sensor s precipitation accumulation factor the value to be entered is 225 x 100 92 2 244 The suggested procedure to be used for precipitatio
26. smoke 30 Fog 40 Indeterminate precipitation type 50 Drizzle 60 Rain 70 Snow DD D C Not used in the SWS100 Set to 99 9 C EE EE KM Meteorological Optical Range km This is the instantaneous value Standard Operating Data Message for the SWS 100 33 Biral Standard Operating Data J __ Section 2 MESSAGE MEANING FFF Self test and Monitoring see section 4 2 FFF O other self test values OK X other self test faults exist O windows not contaminated X window contamination warning cleaning recommended F Window contamination fault cleaning required O sensor not reset since last R command X sensor reset since last R command 34 If selected this will be the checksum character The checksum is off by Edd default Table 2 2 SWS 100 Operating data message format A typical data message from an SWS 100 sensor is as follows SWS100 001 060 00 14 KM 99 999 30 99 9 C 00 14 KM XOO Standard Operating Data Message for the SWS 100 Biral Section 2 Standard Operating Data 2 3 Standard Operating Data Message for the SWS 200 The data message format is lt Date gt lt Time gt SWS200 NNN XXX AA AA KM BB BBB CC DD D C EE EE KM FFF lt cs gt lt crlf gt MESSAGE MEANING lt Date gt Optional Date string in the form DD MM Y Y Time Optional Time string in t
27. test Capabilities Biral Product Overview Section 6 6 12 SWS Sensors external dimensions All SWS sensors have dimensions as shown below The diagrams show the SWS 200 and SWS 250 versions The SWS 050 and SWS100 versions do not have the back scatter hood and window Backscatter receiver 330 242 315 Figure 6 4 External Dimensions of SWS Sensors Dimensions in mm 81 SWS Sensors External Dimensions Biral Index KK Section 7 7 INDEX A ACCESSORIES Ambient Light Sensor 25 dE Ee de fae GN e SM Calibration Kit intret exert ertet dae xS ER OR EE WDR EUER E US HR TE Mains Adapter Power and Signal Cables Transit Case o AFTER SALES SUPPORTH A AW I Cen ud y y Ud ALl Gn dansa AMBIENT LIGHT SENSOR o iiie erede ee tae FD Yu YA e ene ep EDNA FANA ERE le ea Urna NAIN ADUR ANY sieste te mener eee adr dea n Data Message Extension ANALOG DATA OUTPUT 8 64 79 Connections for Optional 0 4 20mA orte e ide rere re eee cde a GEO Heart 8 B BACKSCATTER RECEIVER 53 54 62 65 BAUD RATE 1 I OPE EH HOD HERD dd IW dee o didi bi tht 10 21 28 BIRAL SENSOR INTERFACE SOFTWARE eese ethernet thnnn ee en netten UL LL eet eter arse enne terere annee 1 10 28 49 51 Power and Signal Cables a cet erroe eae ree RR ERR e rH YD O Ea eos 2 65 Connecting CALIBRATION Calibration Certificate C
28. test values OK X other self test faults exist O windows not contaminated X window contamination warning cleaning recommended F Window contamination fault cleaning required O sensor not reset since last R command X sensor reset since last R command 22 If selected this will be the checksum character The checksum is off by default Table 2 1 SWS 050 Operating data message format A typical data message from an SWS 050 sensor is as follows SWS050 001 060 00 14 KM 30 022 18 XOO Standard Operating Data Message for the SWS 050 z Biral Section 2 Standard Operating Data 2 2 Standard Operating Data Message for the SWS 100 The data message format is lt Date gt lt Time gt SWS100 NNN XXX AA AA KM BB BBB CC DD D C EE EE KM FFF lt cs gt lt crlf gt MESSAGE MEANING lt Date gt Optional Date string in the form DD MM Y Y Time Optional Time string in the form HH MM SS SWS100 SWS100 message prefix NNN Instrument identification number set by the user XXX Averaging Time period in seconds AA AA KM Meteorological Optical Range km This is the averaged value BB BBB Not used in the SWS100 Set to 99 999 CC Present weather codes From WMO Table 4680 Automatic Weather Station XX Not Ready first 5 measurement periods from restart 00 No Significant weather observed 04 Haze or
29. 00 and SWS 200 Each relay has a Common terminal and NC and NO terminals Function Details Fault Normally energised Releases on fault condition Relay 1 Settable for visibility range 0 02 km to MORyax Settable for visibility range 0 02 km to MOR yAx OR Relay 2 Triggered by presence of Precipitation OR Triggered by presence of Snow Switching Voltage Max 220 Vdc 250 Vac Biral Switching Current Max 2A Switching Power Max 60 W 125 VA Contact Type Silver alloy with gold alloy overlay Table 6 13 Relay specification Analog Outputs Relay Outputs 79 Product Overview i WMH Section 6 6 11 Sensor Remote Self Test Capabilities 80 Optical Source Power Forward Scatter Receiver Sensitivity Back Scatter Receiver Sensitivity not SWS 050 or SWS 100 Transmitter Window Contamination Forward Scatter Receiver Window Contamination optional on SWS 100 and SWS 200 Back Scatter Receiver Window Contamination optional on SWS 200 Power Supply Voltages Non Volatile Memory Checksum Test EPROM Check Sum Test Restart Occurrence Sensor Sample Interrupt Verification RAM Read Write Verification Register Read Write Verification A D Control Signal Test A D Conversion Accuracy Check Input Voltage Check Forward Scatter Background Illumination Level Back Scatter Background Illumination Level SWS 200 and SWS 250 only Sensor Remote Self
30. 050 100 200 250 X ti JRO Check Current Relay Configuration 1 Ps PER Ve ye ve JROx Set NION Relay Configuration See EP EIE section 1 4 11 Send precipitation matrix accumulated over Mnnn last five measurement periods M i nnn nnn y This is a matrix of 16 rows with up to 21 E See Para 3 1 1 readings Zeros to right not displayed OP Check Option Word configuration See para 1 4 1 y y y y OPxxxxxxxx Set configuration options See para 1 4 1 OK y y y y OSAM Check automatic message setting See para 1 4 7 V y y y OSAMx Set automatic message setting para 1 4 7 OK y y y y OSHH Check hood heater setting See para 1 4 8 y y y y OSHHx Set hood heater setting See para 1 4 8 OK y y y y OSWH Check window heater setting See para 1 4 9 y y y y OSWHx Set window heater setting See para 1 4 9 OK y y y y PV Send program version message SI xxxx yy y y y y R Send remote self test and monitoring See Para 312 y y y y message RLn Check o n visibility threshold setting XX XX KM Ue See section 1 4 11 RLn XX XX Set nny n visibility threshold in km OK ME AE See section 1 4 11 RST Restart instrument OK y y y y SN Send instrument serial number Jxxxx xx y y y y T Send instrument times message See Para 3 1 3 V y y y Set auxiliary measurement sample period TA OK V De MES y Range x 2 20 seconds Default 5 TMx Set measurement interval Range x 10 OK 300 seconds Default 60 Send
31. 2 3 5 01 12 5 00 00 00 00 100 105 107 00 00 00 021 0 4063 Check Data Transmission From Sensor If the sensor is NOT in polled mode Wait for the sensor to transmit a Data Message approx 80 seconds from power up If the sensor is in polled mode Send the command D from the PC terminal to the sensor A Data Message will be transmitted immediately Remote Self Test Check Check that the values in the Remote Self Test amp Monitoring Message from the previous Data Transmission to Sensor check are within the ranges indicated below in Table 1 9 Remote self test and monitoring check fields response to R command Field 1 Space Message starts with a space Field 2 100 or 108 Heater state and error flags Field 3 2 450 2 550 Internal reference voltage Field 4 9 00 36 00 Supply voltage Field 5 10 8 13 2 Internal operating voltage Field 6 4 5 5 5 Internal operating voltage Field 7 10 8 13 2 Internal operating voltage Field 8 00 00 Not applicable in this check Field 9 00 00 Not applicable in this check Field 10 85 105 Transmitter power monitor Field 11 80 120 Forward receiver monitor optional Field 12 80 120 Back receiver monitor SWS 200 and SWS 250 only Field 13 00 99 Transmitter window contamination Field 14 00 99 Forward receiver window contamination optional Field 15 00 99 Back receiver window contamination optional Field 16 Temperature C Field 17 3300 4
32. 200 ADC Interrupts per second Table 1 9 Remote self test and monitoring check fields 29 STEP 6 Test and Commissioning Sensor Setup Section 1 30 1 6 4 Calibration Check The sensor is fully calibrated before it leaves Biral However if you would like to carry out a user confidence calibration check please follow the calibration check procedure in section 5 page 55 to ensure that the MOR value changes ie the sensor responds to changes in visibility THIS PROCEDURE CAN ONLY BE COMPLETED IF A SUITABLE SWS CALIBRATION KIT IS AVAILABLE CONGRATULATIONS YOUR SENSOR SHOULD NOW BE FULLY CONFIGURED TESTED AND INSTALLED READY FOR USE THE REMAINDER OF THIS MANUAL COVERS STANDARD DATA MESSAGES COMMANDS AND RESPONSES OPERATIONAL AND MAINTENANCE PROCEDURES CALIBRATION CHECK AND RE CALIBRATION PROCEDURE SENSOR DETAILS AND SPECIFICATIONS STEP 6 Test and Commissioning B I ira Section 2 Standard Operating Data 2 STANDARD OPERATING DATA Biral When in standard mode a data message will be output from the sensor every measurement period default 60 seconds When in polled mode the same message is output only in response to the D command The operating mode is checked by sending command OSAM The standard mode default is selected if the response is 01 If the response i
33. Biral OPERATION and MAINTENANCE MANUAL SWS Present Weather Sensors Pn or S x lf L 4 H e SWS 050 SWS 100 SWS 200 SWS 250 PROPRIETARY NOTICE The information contained in this manual including all illustrations drawings schematics and parts lists is proprietary to BIRAL It is provided for the sole purpose of aiding the buyer or user in operating and maintaining the instrument This information is not to be used for the manufacture or sale of similar items without written permission COPYRIGHT NOTICE No part of this manual may be reproduced without the express permission of BIRAL 2014 Bristol Industrial and Research Associates Limited BIRAL Biral Biral P O Box 2 Portishead Bristol BS20 7JB UK Tel 44 0 1275 847787 Fax 44 0 1275 847303 Email info biral com www biral com Manual Number 105223 Revision 06D Biral il CONTENTS GENERAL INFORMATION Manual Versiot ses oss eek socket t eth re E WG 9m 5 i Contents sti Yd A Y YG Y FY Y FO 11 Figures and Tables iie tat etm tee leta eae qp rt ADNA tae iii The sensors covered in this manual iv Features of the SWS sensors een V Customer satisfaction and After Sales Support vi Contacting Biral te de ettet mettre tete ve ee tenete deeded baat vi Three year SAN vii If you need to return the sensor vii CE Certification Safety sister vii SENSOR SET UP coco roonanoss 1 1 1 STEP 1 Unpack
34. ER of electric shock Exercise caution when performing this measurement WARNING Only connect the power cable if it matches the voltage requirements of the sensor Damage caused by improper voltage connection is not covered under warranty 1 6 2 Checking Data link 1 Connect the power input cable to a local power source do not turn power source on 2 Connect the signal wires to a PC running the Biral Sensor Interface Software If this is not available use a terminal program for example Windows Hyper Terminal For RS422 485 sensors a RS422 to RS232 converter must be used Note Biral recommends testing to be done with RS232 or RS422 as applicable When you are confident that the sensor is working it can then be set up for RS465 if required 3 Configure the terminal program as follows Default Interface Parameters Bad Rate nier NO GR ANG Uw 9600 Data Bits eene HI 8 Stop Bits ele a 1 Patty cioe i Deeds None Flow Control o ee WY e eria None STEP 6 Test and Commissioning B I ira Section 1 sensor set up 4 1 6 3 Biral Turn the local power source ON If communications are working the sensor will respond with Biral Sensor Startup Check Data Transmission To Sensor Send the command R from the PC terminal to the sensor The sensor will respond with its Remote Self Test amp Monitoring Message For example 100 2 509 24 1 1
35. Relay contacts are rated 2A 250V AC For ease of assembly it is recommended that 22AWG stranded 7 30 or solid wire conductors or equivalent are used These are ideal for the low power requirements of the system However each connector can accommodate wires from I6AWG down to 26AWG 1 5 to 0 2 mm of solid or stranded construction They require a strip length of 5 mm Care must be taken to ensure that the voltage rating of the cable is correct for the switching application requirement If the relays are to be used with mains voltages protective earth bonding of the sensor housing should be carried out to ensure compliance with all national and local safety requirements STEP 2 Electrical connections Sensor Setup Section 1 1 2 5 Pin connections for 0 10 V analogue output An analogue output representing Meteorological Optical Range MOR as a signal between 0 and 10 V is standard on the SWS 100 and SWS 200 sensors The connections are as follows Table 1 4 Pin Number Designation J12 H 0 10V Analogue Output MOR ve J12 I 0 10V Analogue Output MOR ve Table 1 4 Connections for 0 10 V analogue output 1 2 6 Pin connections for sensors ordered with the OPTIONAL 4 20mA or 0 20 1 2 7 mA analogue output current loop An additional analogue output representing MOR as a current between 4 and 20 mA or 0 and 20 mA is available as an option on the SWS 100 and SWS 200 sensors The
36. SWS 200 and SWS 250 See Figure 4 1 Hood Heater The hood heaters are high power heaters designed to prevent the build up of frozen precipitation in the hoods These heaters operate according to the ambient temperature only being switched on when the temperature is below 22C When switched on it is easy to detect the heating by placing a finger on the end of each hood The hood heater is the raised red mat on the inside of the hood near the window Figure 4 1 Hood Heater When the temperature is above the 49C the heaters will be switched off but may be controlled using a PC running the Biral Sensor Interface Software If this is not available use a terminal program for example Windows Hyper TerminalTM The heaters may be switched on temporarily using the command DHO and off again using the command DHX see section 3 1 4 1 3 Window Cleaning SWS sensors are optical instrument and are therefore susceptible to accumulation of contaminants on the windows in the hoods The windows should be cleaned by gently wiping the windows using a pure alcohol propanol and a soft cloth appropriate safety precautions must be taken when using pure alcohol All SWS sensors are fitted with a Transmitter Window monitoring system which compensates for contamination and will flag a warning when the contamination reduces the signal by more than a pre set amount default 10 when this occurs the appropriate part of Self test and Monitoring me
37. a BS tete ete tp ede Ir 8 Stop SI E 1 Paritynn res nt HERR os evs Rene qe None Flow Control None If using Hyper Terminal the options Send line ends with line feeds and Echo typed characters locally in ASCII set up should be checked STEP 3 Eguipment Test Biral Section 1 AS sensor set up 1 Turn the local power source ON If communications are working the sensor will respond with Biral Sensor Startup 2 Check Data Transmission To Sensor Send the command R from the PC terminal to the sensor The sensor will respond with its Remote Self Test amp Monitoring Message For example 100 2 509 24 1 12 3 5 01 12 5 00 00 00 00 100 105 107 00 00 00 021 0 4063 3 Check Data Transmission From Sensor If the sensor is NOT in polled mode Wait for the sensor to transmit a Data Message approx 80 seconds from power up If the sensor is in polled mode Send the command D from the PC terminal to the sensor A Data Message will be transmitted immediately 4 MOR Calibration check Carry out the calibration check procedure in section 5 1 page 55 to ensure that the MOR value changes i e the sensor responds to changes in visibility NOTE as this calibration check is being carried out indoors the MOR value will NOT necessarily agree with that marked on your calibration reference plague NB The sensor is fully calibrated before it leaves Biral THIS PROCEDURE CAN ONLY BE COMPLETED IF
38. accumulated precipitation message IN XXX XX XXXX X A Accumulated precipitation in mm y y XXXX Accumulation time in minutes AC Clear accumulated precipitation OK y y ADR Send RS485 address See para 1 4 6 xx y y y y t RS4 ADRxx Set RS485 address OK 4 Range 00 99 See paragraph 1 4 6 BB Send instantaneous value of backscatter NE EXCO i BL Send EM valg of Total EXCO less precipitation particle component BT Send instantaneous value of Total EXCO xxx xx y y y y CA Perform precipitation amount calibration See para 5 3 y Calibration must be enabled KaR Perform both forward scatter and Saa CE backscatter Not 050 or 100 EXCO pee V fv ly dv calibration Calibration must be enabled CO Enable calibration OK y y y y CX Disable calibration OK y y y y D Send latest data message See section 2 y y y y Turn hood heaters on temporarily If off at DHO time of command the heaters will turn off OK y y y y after 2 minutes for maintenance only Turn hood heaters off temporarily Ifon at DHX time of command the heaters will turn on OK y y y y after 2 minutes for maintenance only Set instrument identification number IDx displayed in data message OK y y y y Range x 1 to 999 Default 1 43 Biral Sensor Commands Commands and Responses Section 3 Applicability SWS Command Function Response
39. alibration Kit eee estere ettet Mu e deter Rd Assembly aded citi A WA GI e DL AEE dea eoi e boca ee rendre Precipitation Amount T Re calibration CE GERTIFICATION SAFETY e reete FU A copio LEAD EF DE YI E S e ER COP CREE ERE sien tes VII CHECKSUM M EE LRCURSASS ON Normal not RS485 COMMANDS AND RESPONSES In Hd M Ra HERE Sensor RESPONSES ceste an aa COMMUNICATION SPECIFICATION COMMUNICATIONS CONFIGURATION CONFIGURATION OPTIONS 253 Automatic Messages Baudrate ue A YW a Checksum Date and Time Stamp Hood Heaters Window Heaters CONTACT DETAILS D DATA MESSAGE n ee Pede dem opc adelaida Ambient Light Sensor Check Data Transmission Example of Data Message DATE AND TIME STAMP deesse cenae coser susie ea eaae eod YNAD deste dea de epe eb co deae ck de eaa do Ro cobsad dovetecavescbccd ea dansocdeaessed dace DIMENSIONS OE SENSOR 21 25 52 25 1 HEREDI ERU OU HERI didier flat 82 Section 7 ndex E ELECTRICAL CONNECTIONS Lc yd me Sods In ep eti als dau Poe dote den ad nd pM Me RUE AREE e mie Ambient Light Sensor P Power and Signal Cables ss EMC COMPLIANCE eer ENVIRONMENTAL SPECIFICATION ix EQUIPMENT TEST tete ote EE e HE ERU PR HN RR o CURED ite REESE db Sa tach RE en ORIS ERI
40. amination field value is much greater than 10 eg 99 Step 7 Remove the white card Receiver Window Monitor s This procedure is used for the forward scatter receivers on the SWS 050 sensor optional on the SWS 100 and both the forward and back scatter receivers on the SWS 250 sensor optional on the SWS 200 Carry out the following procedure for the forward scatter window and then the back scatter window if applicable Step 1 Clean the forward or back scatter receiver window Step 2 Wait for operational data in message from the sensor Step 3 Send the command R Step 4 Verify that the Forward or Back Scatter Receiver Window Contamination field value is 00 to 02 Step 5 Insert a white card in the forward or back scatter receiver hood that blocks the window and almost touches it similar to Figure 4 2 Transmitter Hood with White Card Step 6 Wait for operational data message from the sensor Step 7 Send the command R Step 8 Verify that the Forward or Back Scatter Receiver Window Contamination field value is much greater than 10 i e 99 Step 9 Remove the white card 4 3 3 Receiver Background Brightness Measurement Checks The receiver background brightness value measures the optical signal detected by the receiver caused by the ambient background This value is used to set the threshold values for precipitation particle detection The following procedure will check this function for the forw
41. ard scatter receiver on all SWS sensors and additionally the back scatter receiver on models SWS 200 and SWS 250 User Confidence Checks 53 Biral Maintenance Procedures Section 4 54 Step 1 Step 2 Step 3 Step 4 Step 5 NOTE Step 6 Insert grey foam plugs Zero Plugs supplied in the calibration kit into the forward scatter receiver hood and back scatter hood if applicable blocking all light from the window Send the command R Verify that the value in the Forward Back Scatter Receiver Background Brightness field is less than 00 06 forward scatter is field 8 backscatter is field 9 see section 3 1 2 Remove the zero plugs from the Sensor Head receiver hoods While shining a flashlight directly into the appropriate receiver window send the command R This test requires the use of a filament bulb flashlight There is insufficient IR radiation from a visible LED source to carry out this test successfully Verify that the value in the Forward Back Scatter Receiver Background Brightness field is much greater than 00 06 User Confidence Checks Biral Section 5 Calibration Procedures S CALIBRATION PROCEDURES This section explains how to CHECK the calibration of the sensor and ONLY IF NECESSARY how to recalibrate it ALL THE PROCEDURES IN THIS SECTION REQUIRE A SWS CALIBRATION KIT The calibration of the forward scatter and the back scatte
42. ation fault The window contamination is above 30 Although the visibility reading is still corrected using this contamination figure the accuracy may deteriorate as the contamination increases The windows require cleaning NOTE The ALS 2 has an additional code of S This indicates that the sensor is saturated with a VERY bright light source such as direct view of the sun Although the reported light level will be in error it can be implied that the true ambient light level is high 4 2 3 Least Significant Character Other Self Test errors A variety of operating parameters are regularly checked against normal operational figures as an early warning of possible sensor faults This character indicates whether all parameters other than window contamination are normal This Self test code can be one of two characters O or X These have the following meaning O No Fault No action reguired X Internal error Send command R to list all internally monitored parameters Check against paragraph 3 1 2 to determine the cause of this error Send command RST to restart the sensor If the fault persists arrange for the sensor to be serviced at the earliest possible opportunity 4 3 User Confidence Checks The following user confidence checks reguire bi directional communications with a PC running the Biral Sensor Interface Software If this is not available use a terminal program for example Windows H
43. ble Unused Glands Any glands not in use should be sealed with the supplied sealing plugs to retain the integrity of the weatherproof housing Connecting the power supply and signal cable The power and signal cables are connected to the instrument using the connector strip along the bottom edge of the main circuit board adjacent to the cable glands i UL J12 Connect the power T nM MON Connect the signal cable here E des i AN E cable here Figure 1 3 Power and Signal Connections This connecting strip is of a lever clamp design The wire is released by pressing on the lever with a small screwdriver with a flat blade of no more than 2 5mm STEP 2 Electrical connections Biral Section 1 Sensor set up For ease of assembly it is recommended that 24A WG stranded 7 32 or solid wires are used or equivalent These are ideal for the low power requirements of the system However the connectors can accommodate wires from 20AWG down to 26AWG 0 5 to 0 13 mm of solid or stranded construction They require a strip length of 11 mm Connecting the power supply All SWS sensors require an input voltage supply between 9 and 36V DC This is typically 24V DC supply at 3 5W This will rise to typically 6W if the no dew window heaters are in use See Figure 1 3 for the identification of the connector strip This is split into two sections a 6 way block labelled J11 and a 12 wa
44. ck time The format of the command is STHHMMSS where HH is the hours in 24 hour clock 00 23 MM isthe minutes 00 59 SS is the seconds 00 59 The sensor will respond with OK Checksum to verify message A checksum byte can be included with messages sent by the sensor to verify that noise in the communications link has not changed the message Generally noise is not a problem and checksum verification is not reguired This is controlled by the Options Word setting see Table 1 6 Options word lower byte Note if RS485 communications are selected then this checksum is not used By default the sensor is configured at the factory with checksum DISABLED STEP 4 Configuration Options e Biral Section 1 sensor set up To enable checksum The sensor can be configured to generate messages with a checksum byte by setting the sixth bit in the options word Step 1 Send the command CO Step 2 Send the command OP100000 Note to enable checksum and time date stamp send OP100001 PLEASE BE EXTREMELY CAREFUL IN SETTING THE CORRECT BIT IN STEP 2 AS SETTING THE WRONG BIT WILL RESULT IN THE SENSOR FUNCTIONING INCORRECTLY Biral To check the setting of the options word send the command OP The sensor should respond 00000000 00100000M NB M is the checksum character To disable checksum To disable the checksum send the command OPO in step 2 above
45. command CO Sensor replies OK STEP 3 Send command CE Sensor replies CLEAN WINDOWS BLOCK FWD SCAT RCVR OPTICS BLOCK TRANSMITTER OPTICS BLOCK BK SCAT RCVR OPTICS not for the SWS 050 or SWS 100 INSTALL REF STD ENTER FWD SCAT VALUE FORM XXX XX STEP 4 Fit the grey foam plugs supplied with the calibration kit against all three of the windows only two needed for the SWS 050 and SWS 100 Sensor Re calibration 59 Biral Calibration Procedures Section 5 60 STEP 5 STEP 6 STEP 7 STEP 8 STEP 9 STEP 10 STEP 11 STEP 12 STEP 13 Enter the forward scatter calibration value from the calibration plaque SWS 200 and SWS 250 Only Sensor replies ENTER BACK SCAT VALUE FORM XXX XX Enter the back scatter calibration value from the calibration reference plaque Sensor replies CAL IN PROGRESS Wait for approximately 2 minutes Sensor replies REMOVE OPTICS BLOCKS ENTER OK Remove grey foam plugs from all windows and send text OK Sensor replies CAL CONTINUES Wait for approximately 2 minutes Sensor replies CAL COMPLETE REMOVE REF STD Note Do not remove the calibration reference plaque at this point Wait for the third data message to be received at the PC Send the command BT and note the response value Send the command BB and note the response value SWS 200 and SWS 250 only If the response to the BT command is within 3 of the forward
46. current date and time See paragraph FRIDAY TR 1 4 2 The final 000 is an internal fixed 23 03 12 N A N y constant 13 15 25 000 44 Sensor Commands Biral Section 3 kz Commands and Responses Applicability SWS Command Function Response 050 100 200 250 WT Send current Window COMANN XX q threshold for warning indication Set window contamination threshold for a WTx warning indication op in transmission OK 4 Range 0 to 30 Calibration must be enabled Default 10 Set communication baud rate See para B y ant Range 1 7 1 4 10 y y y SDWDDM DW Set current date See paragraph 1 4 2 OK y y y y MYY STHHMM i Set current time See paragraph 1 4 2 OK y y y y Table 3 1 Commands for SWS series of sensors indicates that these commands are only applicable if the relay option has been taken which is only available on the following models SWS 050T SWS100 amp SWS200 3 1 1 Command M Send Precipitation message This command is only available in the SWS 250 sensor The sensor responds by sending a precipitation matrix accumulated over the last five measurement periods This is a matrix of 16 rows with up to 21 readings each being the number of precipitation particles of that specific size and velocity Zeros to right are not displayed The meaning of the matrix is graphically presented in Paragraph 6 3 2 Figure 6 3 Precipitation Reco
47. data is automatically integrated into the main SWS sensor data stream see section 2 Standard Operating Data The ALS 2 connections are taken to a daughter board which is mounted on the main SWS sensor processor board in the position shown in Figure 1 6 ALS 2 Connecting System SWS ALS 2 daughter board Connection to SWS processer J9 ALS 2 Connector SYW ds pp LAU STATUE RI d 12 uo 7 S d di AX Wire Colour List SWS Sensor Power Connector Q1 Flying lead connection to enclosure lid J3 Connection to SWS processor J8 Connection to SWS processor main terminal strip J11 Figure 1 6 ALS 2 Connecting System The SWS sensor power supply is now connected to J1 on this ALS 2 connection board with the positive and negative leads as marked on the circuit board The hood heater supply if used is still connected to the main processor terminal strip pins A and B and the data connections are not affected See section 1 2 3 for details The ALS 2 cable is connected to J2 with the wire colours as shown on the circuit board adjacent to J2 Note both JI and J2 have removable reversible connection plugs for ease of assembly Check wire colours against list on board before applying power to the combined system STEP 2 Electrical connections 9 Sensor Setup Section 1 13 STEP 3 Equipment Test 1 3 1 10 Biral recommends that the equipment is powered and checked on the bench before site in
48. describes the meaning of the self test codes provided in all the standard data messages It specifies what actions if any are reguired to restore the sensor to full operational capability 4 1 General Checks 48 4 1 1 4 1 2 A general check of the physical condition of the sensor should be carried out at regular intervals Particular attention should be paid to the condition of the cable s from the base ofthe unit It is suggested that this is carried out at least every three months in conjunction with window cleaning see 4 1 3 below De mister Heaters fitted as standard to all sensors The window de misters are low powered heaters designed primarily to prevent condensation They maintain the temperature of the windows at a few degrees above ambient temperature The default setting is ON See section 1 4 9 for details The warmth may be detected with the finger on the window but is easier to detect using a thermometer with surface temperature probe The windows should be between 5 and 109C above ambient temperature after at least 10 minutes operation Ensure that windows are cleaned after coming into contact with the skin Hood Heaters optional Hood heaters are fitted as standard on the SWS 050 and SWS 250 sensors and are an option for the other models They are fitted to the inside of each of the hoods 2 on the General Checks Biral Section 4 AMA Maintenance Procedures SWS 050 and SWS 100 with 3 on the
49. e should be taken to ensure that the sensor is situated away from any surfaces which could causes of reflections of the IR illumination from the transmitter for example walls trees and people etc Reflected IR illumination entering the sensor s optics will cause errors in the reported visibility measurements Air flow Care should be taken to ensure that the sensor is situated away from objects that disrupt the normal flow of air to and through the sensor sampling volume for example walls trees and other eguipment etc RFI Interference In addition to the above mentioned natural effects that may influence the performance of the sensor due regard should also be given to radiated electrical interference Sources of potential interference include radio antennas and radiated transients from high voltage plant located near to the sensor installation STEP 5 Installation 23 Sensor Setup Section 1 24 1 5 2 Height Above Ground The optimum height at which to mount the sensor depends on the application The table below shows recommended heights Application Typical height Comment Recommended height for the sensor sample volume is the 1 5 to 2 meters y Highway fog warning systems average distance of a vehicle 4 9 to 6 6 feet t driver s eyes above the roadway This is the standard height for EM 4 3 meters 14 feet visibility sensors in the U S Airport applications ab
50. ement capabilities the SWS sensor has a number of distinctive physical features Compactness The sensor is a single package small in size and weight It can be readily installed by one person and can be used in portable or fixed installations Proven Software The basic software incorporated into the sensor has evolved over a long period of time and has been tested and proven in hundreds of sensors Sensor Features 65 Biral Product Overview Section 6 Ease of Maintenance and Calibration Routine maintenance including a check on calibrations is performed in a matter of a few minutes A re calibration if required takes only slightly longer and is easily performed by one person 6 3 Present Weather Measurements 6 3 1 6 32 Present Weather Definition The term Present Weather is generally employed to define a large class of atmospheric phenomena that includes tornado activity thunderstorm activity precipitation obstructions to vision and other atmospheric phenomena such as aurora For purposes of Automated Present Weather Sensors the term present weather is restricted to those atmospheric phenomena that are local to the sensor These phenomena include 1 All forms of liquid and frozen precipitation e g rain drizzle snow snow pellets snow grains ice pellets formerly sleet and hail and 2 Those suspended particles that are classed as obstructions to vision namely mist fog haze
51. er Ambient Light Sensor The Biral ALS 2 ambient light sensor can be readily integrated with any SWS sensor This provides an accurate measure of the prevailing apparent light intensity in any specific direction The intensity measurement over a very wide range lt 2 up to 40 000 cd m is integrated into the standard sensor output data stream see section 2 5 Data Message Variations For ALS 2 6 2 Sensor Features The SWS sensors are both visibility sensors and present weather sensors They have the necessary optimum configuration for accurate measurement of visibility in the densest of fogs to very clear air conditions They can detect the onset of precipitation as readily as a human observer and can measure the size and velocity of precipitation particles Unigue patented technigues utilising precipitation size velocity distributions and backscatter forward scatter ratios provide essentially error free identification of the type of precipitation False alarms and false identifications are kept to a minimum by the application of empirically derived algorithms sensitive to the characteristic of electronic noise and insects Also unique is the sensor s capability for separating the contribution of extinction due to precipitation from the total atmospheric extinction coefficient thus giving the sensor the capability to identify fog whenever it is simultaneously present during a precipitation episode In addition to its optimal and unique measur
52. essen 61 PRODUCT OVERVIEW iei best eps o SUR Vp EUM Tete ee e RUE 62 6 1 SWS 050 SWS 100 SWS 200 and SWS 250 Present Weather Sensors 62 6 2 Sensor Features insidere lettre tee ertet dte dr da 65 6 3 Present Weather Measurements 66 6 4 Visibility Measurements 66 6 5 Precipitation Measurement sese 67 6 6 Sensor Specifications sanne e eene enne 75 6 7 Instrument Characteristics essseeeeeeeeeeeen nennen 76 6 8 Digital Communication Interface sess 78 6 9 Analog Outputs 3 rtt re tr FF e EF nn Er 79 6 10 Relay Outputs itte redeat e reed rede teri dieta 79 6 11 Sensor Remote Self Test Capabilities sure 80 6 12 SWS Sensors external dimensions 81 7 INDEX sionisme 82 LIST OF FIGURES Figure 1 1 SWS 200 in Packing Ln nennen nenne 2 Figure 1 2 CableiGlands wae tenente ote reet rette eti tet gente 3 Figure 1 3 Power and Signal Connections seen 4 Figure 1 4 Location of J7 RS232 422 485 select 6 Figure 1 5 Relay Connections 7 Figure 1 6 ALS 2 Connecting System essere enne nennen 9 Figure 1 7 SWS 050 and SWS 100 Orientation esee 25 Figure 1 8 SWS 200 and SWS 250 Orientation eese 25 Figure 1 9 U Bolt Mount
53. fitted with an Ambient Light Sensor ALS 2 the data output strings are identical to the standard message with the following appended to the message prior to the optional checksum lt cs gt and the carriage return and line feed lt crlf gt NOTE for the SWS250 the ALS 2 data is integrated into the standard data message format see section 2 4 page 37 ALS FAAAAA BBB Message Meaning ALS ALS data message prefix AAAAA ALS Signal 1 minute averaged value cd m BBB ALS Self Test and Monitoring see section 4 2 O Other self test values OK X Other self test fault exists O Window not contaminated X Window contaminated cleaning recommended reguired F Window contaminated fault S Sensor input saturated O Sensor not reset since last R command X Sensor reset since last R command 42 Table 2 6 Message extension for ALS 2 A typical data message from an SWS 200 sensor with an ALS 2 is as follows SWS200 001 060 00 13 KM 00 000 30 24 5 C 00 13 KM XOO ALS 00118 000 Data Message Variations for ALS 2 e Biral Section 3 3 COMMANDS AND RESPONSES 3 1 Sensor Commands Commands and Responses NOTE All commands should be terminated with Carriage Return gt and Line Feed gt lt crlf gt see paragraph 1 3 Applicability SWS Command Function Response 050 100 200 250 Send
54. ge or visibility values depend heavily on the location and prevailing weather conditions and should only be carried out with the sensor MOUNTED OUTSIDE AND ON A CLEAR DAY VISIBILITY gt 10KM POWERED FOR AT LEAST 1 HOUR NOT LOCATED NEAR A WALL OR OTHER OBSTRUCTION NOT RECEIVING OPTICAL REFLECTIONS FROM SURFACES OR CLOTHING ASSEMBLING THE CALIBRATION REFERENCE PLAQUE r E Attach the arm to the round calibration screen oe fo y Step 2 Fix this assembled SAD calibration reference MET plaque to the sensor as pictured to the left Figure 5 1 Assembly of Calibration Reference Plaque Example of plaque in situ on SWS 200 Calibration Check 2 Biral Section 5 Calibration Procedures Note All commands should be terminated with Carriage Return gt and Line Feed gt lt crlf gt see Paragraph 1 3 STEP 1 STEP 2 Zero Check STEP 3 STEP 4 STEP 5 STEP 6 STEP 7 STEP 8 Gain Check STEP 9 STEP 10 Clean all windows on the sensor using pure alcohol propanol and soft cloth or tissue preferably lens tissue Check the cleanliness using a portable light if possible Step I may not be necessary if checking or commissioning a new sensor Attach the calibration reference plague to the sensor as shown in Figure 5 1 power to the sensor need not be removed Do not stand close to the sensor during calibration as reflections may cause errors in the reported values Inser
55. gnition Matrix page 67 An example response which was during a period of heavy rain is provided below 001 001 001 002 001 001 000 000 000 001 009 002 006 002 001 001 M009 019 020 020 010 002 000 000 001 001 011 033 068 078 056 042 020 005 001 000 001 M003 031 048 041 047 033 038 027 014 009 008 003 004 007 027 020 013 016 011 007 002 008 006 007 004 M000 005 006 005 007 003 000 002 003 001 000 000 000 001 M000 000 006 004 005 000 001 002 001 000 000 001 M000 001 007 000 005 002 001 000 001 M000 000 001 000 001 M000 000 000 001 M000 000 000 000 001 M000 000 M000 Sensor Commands 45 Biral Commands and Responses Section 3 This shows the greatest precipitation amount in rows 5 and 6 relatively slow hydrometeor velocity 3 3m sec and in columns 2 to 8 relatively small hydrometeor size 0 5mm 3 1 2 Command R Send Remote Self Test and Monitoring Message Example response 100 2 509 24 1 12 3 5 01 12 5 00 00 00 00 100 105 107 00 00 00 021 0 4063 The various fields in the response are as follows Field 1 Space The message starts with a space Field 2 ABC Heater state and error flags A 1 Window heaters ON A 2 Not used A 4 A D control signal error 1 EPROM checksum error 2 Non volatile memory checksum error 4 RAM error 8 Register error 2 Ired commanded OFF
56. he form HH MM SS SWS200 SWS200 message prefix NNN Instrument identification number set by the user XXX Averaging Time period in seconds AA AA KM Meteorological Optical Range km This is the averaged value BB BBB Amount of water in precipitation in last measurement period mm CC Present weather codes From WMO Table 4680 Automatic Weather Station XX Not Ready first 5 measurement periods from restart 00 No Significant weather observed 04 Haze or smoke 30 Fog 40 Indeterminate precipitation type 5 Light Drizzle 52 Moderate Drizzle 53 Heavy Drizzle 61 Light Rain 62 Moderate Rain 63 Heavy Rain 7 Light Snow 72 Moderate Snow 73 Heavy Snow 89 Hail DD D C Temperature C EE EE KM Meteorological Optical Range km This is the instantaneous value Standard Operating Data Message for the SWS 200 35 Biral Standard Operating Data Section 2 36 MESSAGE MEANING FFF Self test and Monitoring see section 4 2 FFF O other self test values OK X other self test faults exist O windows not contaminated X window contamination warning cleaning recommended F Window contamination fault cleaning required O sensor not reset since last R command X sensor reset since last R command If selected this will be the checksum character The checksum is off by ad default Table 2 3 SWS 200 Operating data message format A typical
57. he sensor configuration specified at time of purchase This response is detailed in paragraph 3 1 2 Most Significant Character Sensor Reset Flag This will be set to X on start up It will only be set to O following receipt of an R command If it subsequently is set to X this is an indication that a fault such as a power interruption has caused the processor to reset This is generally of no importance but may assist in the diagnosis of any other problem which may have occurred previously Central Character Window Contamination All SWS sensors have monitoring of contamination on the transmitter window The processor compensates the visibility reading to allow for this contamination and also checks the contamination figure against a value of either 10 default value or 30 This Self test code can be one of three characters O X or F dependent on the contamination reading received These have the following meaning O Window contamination is less than 10 Default value can be adjusted by the user see command WTxx paragraph 3 1 No action reguired Self test Codes Biral Section 4 Maintenance Procedures Xx Window contamination warning The window contamination is between 10 and 30 The visibility reading provided is corrected utilising this contamination figure but it is recommended that the windows are cleaned at the earliest possible opportunity F Window contamin
58. ich are included in all sensors Analog Data Output only applicable to SWS 100 and SWS 200 In addition to the standard 0 10 V MOR analog output a 4 20 mA or 0 20 mA current loop output can be supplied This must be reguested by the customer when ordering the sensor Window Contamination Monitoring All SWS sensors have continual monitoring of the transmitter window contamination with automatic compensation of the visibility measurements Additional monitoring of the receiver window s is provided as standard on the SWS 050 and SWS 250 but is optional on the SWS 100 and SWS 200 This provides additional warning of localised contamination build up on all sensor windows See window monitoring information in section 4 2 Self Test Codes Accessories Calibration Kit The calibration kit containing a reference standard calibration plaque in a protective carrying case is employed only at those times that the instrument calibration is being checked see section 5 page 55 for a full description of the calibration process Transit Case A rigid re usable transit case designed to provide full protection to the instrument for regular shipping is available SWS 050 SWS 100 SWS 200 and SWS 250 Present Weather Sensors Biral Section 6 Product Overview Mains Adapter A mains adapter is available if required Power and Signal Cables These may be ordered if required The length must be specified at time of ord
59. igure 1 1 SWS 200 in Packing Other optional components you may have ordered Calibration Kit The calibration kit in a protective carrying case containing a calibration screen a mounting arm referred to as the calibration reference plague when assembled and 3 grey foam plugs see section 5 Calibration Procedures for application Transit Case A rigid re usable transit case designed to provide full protection to the instrument for regular shipping Please note if this is not ordered the sensor is shipped in the standard rugged foam filled box as shown above Mains Adapter A mains adapter to operate the sensor using mains power Power and Signal Cables Power and signal data cables if you are not supplying these yourself The length must be specified at time of order 2 STEP 1 Unpacking the sensor 2 Biral Section Y gt Sensor set up 1 2 STEP2 Electrical Connections ALL ELECTRICAL CONNECTIONS SHOULD BE COMPLETED BEFORE APPLYING POWER TO THE SENSOR 1 2 1 Cables Unless purchased as an option the sensor is not supplied with power and data cables For the power and data cables we recommend you use screened twisted pair cables in a suitable outdoor EMC and UV resistant sheath this is particularly important for the data cables Screens should be earthed by the customers 24 AWG stranded 7 32 or solid wire conductors or equivalent are ideal for the low power requirements of the system ho
60. ing Method 26 Figure 4 1 Hood Heater ocio diiniita erre de DYGN 49 Figure 4 2 Transmitter Hood with White Card 52 Figure 5 1 Assembly of Calibration Reference Plaque 56 Figure 6 1 SWS 050 and SWS 100 Capabilities eee 62 Figure 6 2 SWS 200 and SWS 250 Capabilities see 63 Figure 6 3 Precipitation Recognition Matrix sees 74 Figure 6 4 External Dimensions of SWS Sensors Dimensions in mm 81 List Of Tables Table 1 1 Pin connections for power supply 5 Table 1 2 Pin connections for operating in RS232 interface mode 6 Table 1 3 Pin connections for operating in RS422 RS485 interface mode 6 Table 1 4 Connections for 0 10 V analogue output seen 8 Table 1 5 Connections for 0 4 20mA analogue output 8 Table 1 6 Options word lower byte ss 12 Table 1 7 Relay configuration RRRRRRRRs 22 Table 1 8 Sensor height above ground 24 Table 1 9 Remote self test and monitoring check fields 29 Table 2 1 SWS 050 Operating data message format sse 32 Table 2 2 SWS 100 Operating data message format sse 34 Table 2 3 SWS 200 Operating data message format sse 36 Table 2 4 SWS 250 Operating data message format sse 39 Table 2 5 METAR Code aio re th re A ones 41 Table 2 6 Message extension for ALS 2 oocconnononcnooo
61. ing the Sensor rrr nnr HY RHI HR HY nono I HN 2 1 2 STEP 2 Electrical Connections 4 3 1 3 STEP 3 Equipment Test 10 1 4 STEP 4 Configuration Options ssessssssseeeeereen enne 12 1 5 STEPS Installation E tet WAD reca tede di 23 1 6 STEP 6 Test and Commissioning 28 STANDARD OPERATING DATA sssemsenenensnensesereneneereneneeseesese 31 2 1 Standard Operating Data Message for the SWS 050 sss 32 2 2 Standard Operating Data Message for the SWS 100 n se 33 2 3 Standard Operating Data Message for the SWS 200 sss 35 2 4 Standard Operating Data Message for the SWS 250 sss 37 2 5 Data Message Variations For ALS 2 42 COMMANDS AND RESPONSES e eeeee esee seen seen enata ette eo setas ttes BD DDED te ANDES 43 3 1 Sensor Commands eus 43 3 2 Sensor Responses c siete oia erm este rte RM odds 47 MAINTENANCE PROCEDURES eeeees etes ee eee ee sesso sense taste ense tastes eoa s tta o 48 4 1 General Checks weder RO eoi RU E IER desea 48 4 2 Self est Codes i e trennen eene a 50 4 3 User Confidence Checks 4 51 CALIBRATION PROCEDURES eese esee sete eene eese taste sse ea seta stas eas etse eoa 55 5 1 Calibration Check ue nr teresa cente irse eee e ere 55 5 2 Sensor Re callbratiOl sun eee aene oer ve eer eed 59 5 3 Precipitation Amount Calibration
62. lent EXCO km JJJ JJ Back Scatter Channel Exco km This is the averaged value KKK K C Temperature C Standard Operating Data Message for the SWS 250 z Biral Section 2 Standard Operating Data MESSAGE MEANING ALS signal 1 minute average value cd m Optional if not fitted set to LLLLL 99999 MMM Self Test and Monitoring See section 4 2 O Other self test values OK X Other self test fault exists F Forward Scatter Receiver Flooded with Light B Back Scatter Receiver Flooded with Light X Windows contaminated warning cleaning recommended F Windows contaminated fault cleaning required O Sensor not reset since last R command X Sensor reset since last R command x Windows not contaminated NNNN Number of precipitation particles detected in last minute O0 0000 Amount of water in precipitation in last minute mm PPP ALS Self Test and Monitoring if ALS not fitted set to OOO See 4 2 O Other self test values OK X Other self test fault exists O Window not contaminated X Window contaminated warning cleaning recommended F Window contaminated fault cleaning required S Sensor input saturated O Sensor not reset since last R command X Sensor reset since last R command If selected this will be the checksum character The checksum is
63. m Bandwidth 0 04um Lifetime gt 10 years Modulation Frequency 2000 Hz 76 Instrument Characteristics Biral Section 6 Product Overview Detector Function Details Type Photovoltaic Silicon Response Silicon Filter Bandwidth 0 08um at 0 85um Temperature Sensor Function Details Type Circuit mounted IC Range 60 C to 100 C Power Requirements Function Details Power Source Sensor Voltage 9V to 36V DC 24V typical Power Source Sensor Power 3 5 W Power Source Hood Heaters Voltage 24V DC or AC Power Source Hood Heater Power SWS 050 and SWS 100 24W SWS 200 and SWS 250 36W Additional for ALS 2 option 12W Additional Power for No Dew Window Heaters SWS 050 and SWS 100 1 7W SWS 200 and SWS 250 2 5W Additional Power for ALS 2 Option 1 2 W no window heater 2 0 W with window heater Environmental Function Details Pn Operating Temperature 40 C to 60 C Altitude 0 to 20 000 ft Precipitation All weather Humidity 0 to 100 Protection Rating IP66 67 CE Certified y Instrument Characteristics TI Biral Product Overview Section 6 Function Details EMC Compliant EN61326 1997 1998 2001 RoHS and WEE Compliant y Table 6 10 Instrument characteristics 6 8 Digital Communication Interface Communication Protocol
64. m the amplitude and duration it then determines the particle size and velocity The size and velocity information is collected in a data matrix by the microcomputer and is stored for a time interval the measurement time period usually one minute adequate to provide a statistically significant and representative sample of particle sizes and velocities The size and velocity distributions of particles in the matrix are available to determine the type of precipitation Small numbers of particles with distributions not indicative of rain or snow are considered not to be precipitation and are rejected by false alarm algorithms Once precipitation occurrence has been determined the particle size distribution is used to measure the intensity To measure the intensity the number of particles in each size bin of the matrix are summed and then multiplied by the equivalent volume of water and a calibration constant If the precipitation is identified as snow a density factor is applied to determine the equivalent water content Because the size velocity matrix is a convenient presentation for identifying various forms of precipitation we have termed it the Precipitation Recognition Matrix Types of precipitation are identified from their Signature in the Precipitation Recognition Matrix The Signature is the particle size velocity distribution that is characteristic of each type of precipitation phenomena An example of a precipitation recogniti
65. ment based on both visibility and precipitation outputs ie fog and rain or fog and snow or 2 different fog thresholds SWS 100 and SWS 200 reports WMO 4680 codes reports 35 METAR codes in addition to 39 WMO 4680 codes SWS 250 only There are currently four sensors in the SWS sensor range These are the SWS 050 the SW 100 the SW 200 and the SWS 250 Any of these can be supplied to be used with the Biral Ambient Light Sensor model ALS 2 Throughout this manual the term SWS Sensor is used to refer to features common to all these sensors Biral Customer Satisfaction At Biral we set our standards high and only your complete satisfaction is acceptable to us If you believe your experience has not met these standards we would be grateful if you would contact us so we can rectify any issues you may have equally if you have any positive experiences you would like to share After Sales Support Biral offers support by telephone and email for the lifetime of these sensors even if there has been a change of ownership so please get in touch if you reguire help Similarly if you have any guestions about your new eguipment we are only a mouse click or telephone call away Our contact details are given below NB For your convenience our contact details are also on the label fixed to your sensor Contacting Biral If you would like technical assistance advice or you have any gueries regarding the operation of the senso
66. message OSHH The sensor will send the reply 00 Hood heaters disabled 01 Hood heaters on automatic To set the sensor to the required hood heater configuration send the message OSHHx Where x is 0 z Hood heaters disabled 1 z Hood heaters on automatic The sensor will respond with OK Window heater operating setting The sensor can be set to have the window heaters disabled permanently enabled or for them to be controlled according to contamination levels The default setting is for window heaters enabled and on To check which configuration is programmed send the message OSWH The sensor will send the reply 00 Window heaters disabled 01 Window heaters enabled and on 02 Window heaters enabled and controlled according to contamination levels To set the sensor to the required window heater configuration send the message OSWHx Where x is 0 Window heaters disabled 1 Window heaters enabled and on 2 Window heaters enabled and controlled according to contamination levels The sensor will respond with OK STEP 4 Configuration Options 2 Biral Section 1 Sen sor set up 1 4 10 Baud Rate Configuration Biral Default communication parameters are 9600 8 data bit 1 stop bit no parity and no flow control The baud rate may be changed if required as follows Send B Number Just typing B will bring up the different baud rate options
67. n amount calibration is as follows STEP 1 Send the parameter command CO The sensor replies OK STEP 2 Send the precipitation amount calibration command CA Sensor replies ENTER PRECIP AMT ADJ FACTOR IN PERCENT 30 0 TO 300 0 FORM XXX X STEP 3 Send the required adjustment factor e g 92 2 Sensor replies CAL COMPLETE STEP 4 The precipitation amount calibration process is complete 61 Precipitation Amount Calibration Product Overview Section 6 6 PRODUCT OVERVIEW 6 1 SWS 050 SWS 100 SWS 200 and SWS 250 Present Weather Sensors There are four models in the SWS series of present weather sensors the SWS 050 SWS 100 SWS 200 and SWS 250 They all use the same basic opto mechanical and electronic components and have an optical transmitter and forward scatter receiver The SWS 200 and SWS 250 also have a backscatter receiver to aid in precipitation identification All models have the same time proven software for measuring visibility and precipitation type and performing remote self test diagnostics The measurement capabilities of the models are as follows Sensor Model Capability SWS 050 Visibility Obstruction to Vision SWS 100 Visibility Precipitation type identification 1 Fault relay switch 1 Relay for visibility 1 Relay for precipitation or visibility Figure 6 1 SWS 050 and SWS 100 Capabilities 62 SWS 050 SWS 100 SWS 200 and SWS 250 Present Weather Sensors
68. nd BB lt crlf gt Verify that the response value is within 20 of the back scatter calibration value assigned to the Calibration Reference Plague STEP 13 Remove the calibration reference plague from the sensor If the results of the calibration check have agreed with the value on the label attached to the calibration reference plague within the limits stated above re calibration is NOT reguired A re calibration is reguired ONLY if the MOR values are outside those on the calibration reference plague AND the calibration check has been carried out ACCORDING TO THE CALIBRATION CHECK NOTES on page 56 58 Calibration Check Biral Section 5 Calibration Procedures 5 2 Sensor Re calibration RE CALIBRATING THE METEOROLOGICAL OPTICAL RANGE SHOULD ONLY BE CARRIED OUT IF THE SENSOR HAS FAILED A CORRECTLY PERFORMED USER CONFIDENCE CHECK WARNING ERRORS DURING THIS RE CALIBRATION PROCEDURE WILL CAUSE THE SENSOR TO GIVE INCORRECT DATA BEFORE CONTINUING ENSURE THAT THE SENSOR 1 IS MOUNTED OUTSIDE AND THAT VISIBILITY IS GREATER THAN 10KM 2 HAS BEEN IN CONTINUOUS OPERATION FOR AT LEAST 1 HOUR 3 WINDOWS ARE CLEAN 4 IS NOT LOCATED NEAR A WALL OR OTHER OBSTRUCTION 5 IS NOT RECEIVING OPTICAL REFLECTIONS from surfaces or clothing STEP 1 Set up the sensor with the calibration reference plaque in place see section 5 1 power to the sensor need not be removed STEP 2 Send
69. ng the colon character that begins the message and excluding the lt crlf gt pair at the end of the message The LRC byte is converted to 2 ASCII characters and appended to the message For example the message 42D Checksum is calculated as ASCII string 42D BYTE Values in HEX 34 32 44 3F Sum is E9 One s compliment 0xFF OxE9 0x16 Two s compliment 0x16 1 0x17 Checksum is 0x17 Hex STEP 4 Configuration Options LLL Sensor Setup Section 1 1 4 6 Checksum ASCII characters are 17 Transmitted string will therefore be 42D 17 lt CRLF gt End All communications will end with the standard 2 characters carriage return line feed lt CRLF gt pair ASCII values of 0D amp 0A hex Sensor Addressing RS485 sensors only To use addressable RS485 communication each sensor must have a unigue address in the range 0 99 By default the sensor address is set to 0 Ouerying the sensor address To guery the sensor address send the command ADR The sensor should respond with the address e g 00 Changing the sensor address To change the sensor address send the command ADRxx where xx is a number between 00 and 99 e g ADRO2 sets the sensor address to 02 The sensor should respond with OK Enabling the addressable RS485 Communications The sensor can be configured to use addressable RS485 communications by setting the eighth bit in the options word see Table 1 6 Option
70. nificant weather observed 04 Haze or smoke 30 Fog 40 Indeterminate precipitation type 50 Drizzle 60 Rain 70 Snow Table 6 6 SWS 100 WMO codes Present Weather Codes SWS 200 Code Description XX Not Ready first 5 measurement periods from restart 00 No Significant weather observed 04 Haze or smoke Precipitation Measurements Biral Section 6 Biral Product Overview Code Description 30 Fog 40 Indeterminate precipitation type 5 Light Drizzle 52 Moderate Drizzle 53 Heavy Drizzle 61 Light Rain 62 Moderate Rain 63 Heavy Rain 7 Light Snow 42 Moderate Snow 73 Heavy Snow 89 Hail Table 6 7 SWS 200 WMO codes Present Weather Codes SWS 250 Code METAR Description XX Not Ready first 5 minutes from restart 00 No significant weather observed 04 HZ Haze visibility greater than or equal to 1km 20 Fog in last hour but not at time of observation 21 Precipitation in last hour but not at time of observation 22 Drizzle in last hour but not at time of observation 23 Rain in last hour but not at time of observation 24 Snow in last hour but not at time of observation 30 FG Fog 31 BCFG Fog in patches 32 PRFG Fog becoming thinner in last hour 33 FG Fog no appreciable change in last hour 34 FG Fog begun or becoming thicker in last hour 35 FZFG Freezing Fog
71. nonnnnnnnonnnonnnonnnconcnon nono nocnnoconnnos 42 Table 3 1 Commands for SWS series of sensors sse 45 Table 3 2 Command R response 46 Table 3 3 Command T response 47 Table 3 4 Sensor responses irin a a E e RE E A E oa 47 Table 6 1 Visibility measurement capabilities seen 67 Table 6 2 Precipitation measurement limits 68 Table 6 3 UK precipitation intensity definitions sse 69 Table 6 4 US precipitation intensity definitions 69 Table 6 5 SWS 050 WMO codes 70 Table 6 6 SWS 100 WMO codes 70 Table 6 7 SWS 200 WMO codes 7 Table 6 8 SWS 250 WMO and METAR codes 72 Table 6 9 Sensor specifications 76 Table 6 10 Instrument characteristics essere 78 Table 6 11 Digital communication interface specifications sss 78 Table 6 12 Analog output specification ener 79 Table 6 13 Relay specification sss ener 79 Biral iii General Information iv The sensors covered in this manual Sensor Model SWS 050 SWS 100 SWS 200 Capability Visibility Obstruction to Vision m Biral Visibility Precipitation type identincauon 1 Fault relay switch 1 Relay for visibility 1 Relay for precipitation or visibility Visibility Precipitation type identification 1 Fault relay switch 1 Relay for visibility
72. ntrolled by the Options Word setting see Table 1 6 Options word lower byte To enable Date and Time stamp The sensor can be configured to generate messages with the date and time string by setting the least significant bit in the options word Step 1 Send the command CO Step 2 Send the command OPI Note to enable checksum and time date stamp send OP 100001 in step 2 PLEASE BE EXTREMELY CAREFUL IN SETTING THE CORRECT BIT IN STEP 2 AS SETTING THE WRONG BIT WILL RESULT IN THE SENSOR FUNCTIONING INCORRECTLY Biral To check the setting of the options word send the command OP The sensor should respond 00000000 00000001 To disable Date and Time stamp To disable the date and time stamp send the command OPO in step 2 above To read the current Date and Time Send the command TR STEP 4 Configuration Options 3 Sensor Setup section 1 14 1 4 3 The sensor will respond with the date time message e g FRIDAY 1912114 13 15 25 000 Note the final 000 is a time calibration figure set during final test To set the current Date and Time There are two commands required to set the current date and time SD sets the real time clock date The format of the command is SDWDDMMYY where W is the day of the week 1 7 with Sunday being 7 DD is the date 01 31 MM isthe month 01 12 YY is the year 00 99 The sensor will respond with OK ST sets the real time clo
73. of the message Data This is a variable length ASCII character string as defined in section 2 for each of the models in this range The master has a defined range of commands available for the SWS sensor The SWS sensor has a range of defined data messages These messages can either be sent as a response to a request for data by the master unit or sent without any request on a timed basis according to the instrument user settable configuration However it is recommended that a polled system is used in a multi sensor application as this can avoid most data contention issues through the design of a suitable system operating schedule LRC Checksum This enables error checking allowing the master to request a re send if errors are detected For RS485 a Longitudinal Redundancy Check LRC Checksum is generated on the data NOTE This checksum is different from the optional RS232 RS422 Checksum The LRC is one byte containing an 8 bit binary value The LRC value is calculated by the transmitting device which appends the LRC to the message The receiving device calculates an LRC during receipt of the message and compares the calculated value to the actual value it received in the LRC field If the two values are not equal an error is implied The LRC is calculated by adding together successive 8 bit bytes of the message discarding any carries and then two s complementing the result It is performed on the ASCII message field contents excludi
74. off by default cs Table 2 4 SWS 250 Operating data message format A typical data message from an SWS 250 sensor is as follows SWS250 001 0060 00 14 KM 30 FG FG 000 000 00 14 KM 021 19 021 40 073 54 4022 0 C 99999 X00 0000 00 0000 000 2 Standard Operating Data Message for the SWS 250 39 Biral Standard Operating Data Section 2 2 4 1 METAR Codes NUMBER CODE MEANING XX X Not Ready first 5 minutes from restart 00 No significant weather observed 04 HZ Haze visibility greater than or equal to 1km 20 Fog in last hour but not at time of observation 21 Precipitation in last hour but not at time of observation 22 Drizzle in last hour but not at time of observation 23 Rain in last hour but not at time of observation 24 Snow in last hour but not at time of observation 30 FG Fog 31 BCFG Fog in patches 32 PRFG Fog becoming thinner in last hour 33 FG Fog no appreciable change in last hour 34 FG Fog begun or becoming thicker in last hour 35 FZFG Freezing Fog 40 UP Indeterminate precipitation type 5 DZ Drizzle not freezing slight 52 DZ Drizzle not freezing moderate 53 DZ Drizzle not freezing heavy 57 RADZ Drizzle and Rain slight 58 RADZ Drizzle and Rain moderate 58 RADZ Drizzle and Rain heavy 61 RA Rain not freezing slight 62 RA Rain not freezing moderate 63 RA Rain not freezing heav
75. on matrix is shown in Figure 6 3 Precipitation Recognition Matrix This figure portrays a 16 x 21 matrix array of particle sizes and velocities Sizes are arranged in columns and velocities in rows Precipitation Measurements 73 Product Overview MHR Section 6 MATRIX SCALES HYDROMETEOR SIZE gt O O D O qd O 010 O O10 O d D O quivalent P O D O O D D D q Particle Radius A a olo D O Ol O SRE P E Th RSS SE Ele dr FOE A119013A Figure 6 3 Precipitation Recognition Matrix General size velocity characteristics of various types of precipitation displayed on the precipitation recognition matrix MA Precipitation Measurements Biral Section 6 6 6 Sensor Specifications Product Overview The specifications for all versions of the SWS sensor series are summarised in the following pages Where certain specifications are only applicable to certain models within the range this is stated within that table Visibility Measurements MOR and Precipitation Measurements Function Details Measurement Range MOR Meteorological Optical Range SWS 050 10m to 40km SWS 050T SWS 100 and SWS 200 Selectable from the following options at time of order 10m to 2km 10m to 10km 10m to 20km 10m to 32km 10m to 50km 40km for the SWS 050T 10m to 75km Not the SWS 050T Other ranges between 10m and 75km by special request SWS 250
76. ood Heater Return Option 24VAC or DC J11 C Power 9 to 36V Supply J11 D Power OV Supply JII E amp F Not Used Table 1 1 Pin connections for power supply STEP 2 Electrical connections 3 Biral Sensor Set up Section 1 Pin Connections for RS232 or RS422 RS485 Signal Interfaces The sensors can be operated with RS232 OR RS422 OR RS485 communications It is not possible to operate both the RS232 and the RS422 RS485 together If there is to be a long distance between the sensor and its control computer more than 40 metres then the RS422 or RS485 configuration should be used and a RS422 communications port installed in the control computer RS232 may be useable at low baud rates up to 100 m but reliable communications cannot be guaranteed for more than 40 m See Table 1 2 and Table 1 3 for full connection details Pin Number Designation J12 A RS232 422 485 common 0V J12 B RS232 Tx signals FROM sensor J12 C RS232 Rx signals TO Sensor Table 1 2 Pin connections for operating in RS232 interface mode Pin Number Designation J12 A RS232 422 485 common 0V J12 D RS422 RS485 Rx TO sensor J12 E RS422 RS485 Rx TO Sensor J12 F RS422 RS485 Tx FROM sensor J12 G RS422 RS485 Tx FROM Sensor Table 1 3 Pin connections for operating in RS422 RS485 interface mode Selection of RS232 or RS422 485 communications To select which output to use place jumper J7
77. ove the runway This height may differ in other countries This is a suitable height unless General meteorological 1 8 meters 6 feet the particular application dictates otherwise Table 1 8 Sensor height above ground 1 53 Orientation of Sensor Head The orientation of the sensor heads should be such that the rising or setting sun does not appear in the field of view of the receiver lenses Tt is desirable to avoid sunlight from flooding the receiver optics and to avoid sunlight induced noise spikes from creating false precipitation counts although false alarm algorithms in the sensors invariably eliminate such false counts The recommended orientation is shown in the following two diagrams Figure 1 7 SWS 050 and SWS 100 Orientation and Figure 1 8 SWS 200 and SWS 250 Orientation For the SWS 050 and SWS 100 sensors the optimum position is with the receiver head pointing directly due North For the SWS 200 and SWS 250 the optimum position is with the forward scatter receiver and the back scatter receiver oriented egually either side of due North This is with the backscatter head pointing 34 East of North STEP 5 Installation e Biral Section 1 AS sensor set up For sensors located in the Southern hemisphere 180 should be added to the above directions That is for the SWS 200 and SWS 250 point the backscatter head 34 West of South and for the SWS 050 and SWS 100 point the
78. r SWS 200 and SWS 250 only channels are checked using the procedure detailed below section 5 1 The Calibration Reference Plaque used for the calibration check has been assigned a forward scatter calibration value and a back scatter calibration value These values are shown on the label on the arm of the Calibration Reference Plaque Each Calibration Reference Plaque also has a MOR equivalent value assigned to it This value is shown on the surround of the Calibration Reference Plaque All these calibration values are also provided on the Calibration Certificate sent with the Calibration Kit Assembly of the Calibration Reference Plaque is shown in Figure 5 1 page 56 This shows it attached to a SWS 200 but the assembly is identical for all other models in this range 5 1 Calibration Check The following instructions show how to check the calibration of a SWS series sensor This procedure can only be completed with l A SWS Calibration Kit 2 Connection to a PC running the Biral Sensor Interface Software or if this is not available terminal emulation software such as Windows Hyper Terminal using the serial connection If you need help with this please do not hesitate to contact us contact details on page vi Calibration Check 55 Biral Calibration Procedures Section 5 56 CALIBRATION CHECK NOTES PLEASE READ THESE NOTES BEFORE CONTINUING The MOR Meteorological Optical Ran
79. r please do not hesitate to contact us For enguiries and technical support Contact us by telephone on 44 0 1275 847787 Contact us by fax on 44 0 1275 847303 Contact us by e mail at service biral com vi Biral Three year warranty The SWS Present Weather Sensors come with a three year limited warranty against defective materials and workmanship If you have any questions about the warranty please contact Biral In order to help us to assist you please be sure to include the following information Model of equipment Serial number of equipment Nature of defect Your full name address and contact details Relevant application details and data output Responses to R command see paragraph 3 1 2 page 46 If you need to return the sensor The SWS sensors should give you many years of trouble free service but in the unlikely event that the equipment proves to be faulty and we have asked you to return the sensor to us please address the equipment to BIRAL Unit 8 Harbour Road Trading Estate Portishead Bristol BS20 7BL UNITED KINGDOM The customer is responsible for the shipping costs CE Certification Safety All Biral s SWS sensors comply with the requirements for CE marking Once installed it is the user s responsibility to ensure that all connections made to the sensor comply with all Local and National safety requirements vii Biral Section 1
80. rface using the four mounting holes provided Every effort should be made to ensure that the mounting surface has minimal effect on the air flow and the precipitation flow through the sample volume Even if mounted at the top ofa wall the airflow will be restricted reducing the accuracy of the sensor in certain atmospheric conditions Electrical Grounding Possible instrument failure can result from the damaging effects of over voltage transients induced on the power line and the signal distribution lines Destruction of sensitive components can result from unprotected lines or instrument failure may occur over a long period of time due to slow device degradation Destructive over volt transients can occur in many ways e g lightning induced transients AC power line transients and EMI RFI electromagnetic noise The power control subsystem of the sensor contains transient surge arrestors on all power and signal lines as a standard feature EMI filters are present on the power and data lines entering the power control subsystem It is essential to connect the sensor to earth ground for maximum protection of the instrument In addition if relays are in use and are required to switch mains voltages protective earth bonding will be required to conform with national and local installation safety requirements The following notes are intended to provide some guidance in the design and construction of an electrical grounding system 1 Gro
81. s 00 the polled mode is selected Instructions for setting this configuration are provided in paragraph 1 4 7 page 19 Note All responses from the sensor are appended with carriage return and line feed characters lt crlf gt see paragraph 1 3 There are four different standard messages dependent on the model number These are detailed below in Table 2 1 SWS 050 Operating data message format Table 2 2 SWS 100 Operating data message format Table 2 3 SWS 200 Operating data message format and Table 2 4 SWS 250 Operating data message format Standard Operating Data 31 Standard Operating Data Section 2 2 1 Standard Operating Data Message for the SWS 050 32 The data message format for the SWS 050 is lt Date gt lt Time gt SWS050 NNN XXX AA AA KM BB CCC CC DDD lt cs gt lt crlf gt MESSAGE MEANING lt Date gt Optional Date string in the form DD MM Y Y Time Optional Time string in the form HH MM SS SWS050 SWS 050 message prefix NNN Instrument identification number set by the user XXX Averaging Time period in seconds AA AA KM Meteorological Optical Range km This is the averaged value Obstruction to vision code From WMO table 4680 XX Not Ready first 5 measurement periods from restart BB 00 No significant weather observed 04 Haze or Smoke 30 Fog CCC CC Total Forward Scatter Exco value DDD Self test and Monitoring see section 4 2 DDD O other self
82. s 0 3mm to 0 02 inches 0 5 mm hour Heavy More than 0 02 inches 0 5 mm hour Rain Slight A trace to 0 10 inches 2 5 mm hour Moderate 0 10 to 0 30 inches 2 6 to 7 6 mm hour Heavy More than 0 30 inches 7 6 mm hour Snow Slight Visibility equal to or greater than 5 8 statute miles 0 55 nautical i B miles or 1 000 meters Visibility between 1 4 and 5 8 statute miles 0 2 to 0 55 nautical Moderate miles or 400 to1000 meters H Visibility equal to or less than 1 4 statute miles 0 2 nautical miles a d or 400 meters Table 6 4 US precipitation intensity definitions Based on Federal Meteorological Handbook No 1 Part B 1 Precipitation Measurements 69 Biral 70 Product Overview 6 5 3 Precipitation Reporting Section 6 Any precipitation identified is reported according to the present weather codes from the WMO table 4680 Automatic Weather Station Additionally the SWS 250 reports METAR present weather codes see Table 2 5 METAR codes page 41 The WMO codes utilised by each SWS sensor model are listed below Present Weather Codes SWS 050 Code Description XX Not Ready first 5 measurement periods from restart 00 No Significant weather observed 04 Haze or smoke 30 Fog Table 6 5 SWS 050 WMO codes Present Weather Codes SWS 100 Code Description XX Not Ready first 5 measurement periods from restart 00 No Sig
83. s word lower byte Step 1 Send the command CO Step 2 Send the command OP10000000 Note to enable RS485 and time date stamp send OP10000001 PLEASE BE EXTREMELY CAREFUL IN SETTING THE CORRECT BIT IN STEP 2 AS SETTING THE WRONG BIT WILL RESULT IN THE SENSOR FUNCTIONING INCORRECTLY 18 To check the setting of the options word send the command 000P FF The sensor should respond 0000000000 1000000073 NB 00 is the address and 73 is the LRC checksum character STEP 4 Configuration Options e Biral Section 1 sensor set up 1 4 7 Biral To disable RS485 Communications To disable the RS485 communications 1 e revert to RS422 protocol send the command 000POFF in step 2 above or 000P1FF to enable time date stamp NB 00 is the address and FF is the LRC checksum override character see below Checksum Override When using addressable RS485 communications the sensor will disregard any commands that do not have the sensor address or have an incorrect checksum For a command to be valid it must be prefixed by XX where XX is the address and have the 2 character checksum on the end If the checksum character is set to FF then the sensor will accept the message without checking the checksum This is useful when using programs such as HyperTerminal for diagnostics For example A sensor with address 00 to request a data message Send command
84. ssage in the sensor Data Output Message changes from O no contamination to X warning see paragraphs 2 and 4 2 2 If this registers an X all windows should be cleaned at the earliest convenient opportunity If the contamination General Checks 49 Biral Maintenance Procedures Section 4 continues to increase above a pre set limit of 3090 the accuracy of the instrument may begin to deteriorate The self test monitoring message will change to F and the windows should be cleaned as a matter of urgency The SWS 050 and SWS 250 sensors are additionally fitted with receiver window monitors These monitor the forward scatter window and if fitted the back scatter window This provides better accuracy if there is likely to be different contamination on each window If any of the transmitter or receiver window contamination values go above the pre set limit a warning message X is generated If any of these readings exceed 30 this warning changes to a fault message F Receiver window monitoring is an available option for the SWS 100 and SWS 200 models 4 2 Self Test Codes 4 2 1 4 2 2 50 Self Test and Monitoring information is provided in the standard Operating Data Message This information consists of three alpha numeric characters which have the following meanings NOTE The command R provides a response with full diagnostic information The extent of this information depends on t
85. stallation This is to ensure that you are comfortable with the functionality of the sensor and to pre empt any queries that arise before attempting site installation Note this procedure assumes a default configuration for the sensor please check the Calibration Certificate supplied with your sensor for specific configuration details NOTE In this test and in all subsequent sections of this manual the following convention MUST be observed ALL COMMANDS SHOULD BE TERMINATED WITH lt CARRIAGE RETURN gt AND LINE FEED gt ASCII CHARACTERS 13 AND 10 In this manual this is normally abbreviated to lt CRLF gt Equipment Test Procedure Connect the power pins on the input connector to a local power source do not turn power source on Connect sensor earth lug to earth this may not be necessary but can help prevent communication errors with certain PCs Connect the signal cable to a PC running the Biral Sensor Interface Software If this is not available use a terminal program for example Windows Hyper TerminalTM For RS422 485 sensors a RS422 to RS232 converter must be used Note Biral recommends testing to be done with RS232 or RS422 as applicable When you are confident that the sensor is working it can then be set up for RS465 if required Configure the terminal program either the Biral Sensor Interface Software or Hyper Terminal as follows Default Interface Parameters Paud Rate tuns bte 9600 Dat
86. t GREY FOAM PLUGS in the front of each window blocking out all light There are 3 foam plugs top left in the calibration case you will only use 2 of these for the SWS 050 or SWS 100 Send the command RST lt crlf gt Verify the response OK If the sensor is operating in the polled mode send the D command at 60 seconds intervals If the sensor is set to automatically output data then the sensor will output data every 60 seconds Wait for the fifth 5 data message from the sensor Send the command BT lt crlf gt Verify that the response value is between 0 00 and 0 05 SWS 200 and SWS 250 ONLY Send the command BB lt crlf gt Verify that the response value is between 1 0 and 1 0 Remove the foam plugs Send the command RST lt crlf gt to restart the sensor Verify the response is OK If the sensor is operating in the polled mode send D command at 60 seconds intervals If the sensor is set to automatically output data then the sensor will output data every 60 seconds Calibration Check 57 Biral Calibration Procedures Section 5 STEP 11 Wait for the fifth 5 data message from the sensor Send the command BT lt crlf gt Verify that the response value is within 10 of the forward scatter calibration value assigned to the Calibration Reference Plague STEP 12 SWS 200 and SWS 250 ONLY Send the comma
87. tado rada oce te ivt dere 7 Threshold levels no REMOTE SELF TEST amp MONITORIN Data Message RESPONSES FROM SENSOR To Command M 6 10 16 28 6 10 14 28 43 Configuration Settings Em 16 19 S SELF TEST CODES 20214084 ios SENSOR COMMANDS 53 5 3 3 ties pietate depre YN ere ua baee eee aree eda tpe Tk idee tpe bee da dre cor ebat eR SENSOR DIMENSIONS 4 2 0n died eeu eee e aree siesta viata tete sero aea tee ee etre FF FR deese eie eode edel us SENSOR ORIENTATION SENSOR RESPONSES SENSOR SPECIFICATIONS T Checking Power Supply Remote Self Test Check Self Test Codes A da ind Rai Sensor RESPONSES rss HD e E ASEE MESES ida dd Sensor Sel Test Capabilities nu e Dee p ein eei eden Cep en E REGI T aa da de 80 V VISIBILITY MEASUREMENTS sez mui i a da 75 84 Index Biral Section 7 2 A ndex W WARRANTY Ga die Pa et e ER ad T e DES II VII 28 WINDOW AOI NICE X 49 WINDOW HEATER CRNENRRRERTOTRTTCPH FLY NAD 48 WMOFTABDEE OO L 32 70 Index 85 Biral 86 Notes Biral
88. the signal voltage levels for RS422 RS485 are selected the configuration to select RS422 or RS485 should be set by the user The following paragraphs provide the instructions for this adjustment and details for setting up the RS485 communication if required RS485 Configuration The SWS sensor can be set by the user for either RS422 or addressable RS485 communication protocols The software needs to be configured to use this protocol By default the sensor is configured at the factory for RS422 protocol unless specifically requested when ordering RS485 Protocol Format The RS485 communication protocol is based on the Modbus ASCI Frame Format Each data request and transfer is configured as follows Start 3A Hex Sensor Address 2 Character address field Data As standard SWS message format see Section 2 LRC Checksum 2 Characters Longitudinal Redundancy Check End 2 Characters Carriage return Line Feed Start The colon symbol is used as a start flag which is 3A hex STEP 4 Configuration Options e Biral Section 1 sensor set up Biral Sensor Address The 2 character sensor address is defined by the operator for the unit and programmed as specified in the set up instructions Section 1 4 6 It can be any numeric value between 00 and 99 It is used by the unit to define the recipient of the message and by the slave to define the source
89. und Rod An eight foot ground rod should be used to make contact with moist soil during even the driest periods 2 Lead Lengths No 6 AWG solid copper wire should be used to connect the instrument and thus the transient voltage suppressers to the ground rod Use the shortest and most direct paths to the ground Simply connect the ground lead to the grounding screw provided on the front of the lower mounting flange of the instrument 3 System Interconnections Eliminate all isolated ground loops The shield of the signal output cable for example should be attached only at one end of the cable and left floating at the other end Preferably it should be attached to ground at the sensor end of the signal cable 4 Connections Use tight corrosion proof bare metal connections throughout the grounding system STEP 5 Installation 27 Sensor Setup Section 1 1 6 STEP 6 Test and Commissioning 28 1 6 1 The following steps contain a few basic checks to provide confidence that the unit is functioning correctly after installation These checks are recommendations only and are neither essential nor exhaustive Checking Power Supply Before connecting the power cable to the sensor the supply voltage being provided should be measured to ensure that the voltage present is compatible with the sensor power requirement Use a multimeter to measure the supply voltage which should be between 9V and 36V DC DANG
90. use These definitions can be adjusted at time of manufacture for SWS200 and SWS250 sensors in conjunction with the precipitation intensity definitions see section 6 5 2 for details The above definitions for haze and fog are always used by the SWS050 and SWS100 sensors In the presence of precipitation the sensor software measures the fraction of the atmospheric extinction coefficient due to precipitation and subtracts it from the total extinction coefficient to obtain a guantity we have named EXCO EVENTS If the value of EXCO EVENTS is greater than 3 00 MOR less than 1km then fog is declared to be present in addition to the precipitation as an obstruction to vision Function Details SWS 050 10m to 40km SWS 050T SWS 100 and SWS 200 Selectable from the following options at time of order 10m to 2km Meteorological Optical png Oy Range MOR 10m to 20km 10m to 32km 10m to 50km 40km for the SWS 050T 10m to 75km Not for the SWS 050T Other ranges between 10m and 75km by special request SWS 250 10m to 75km MOR 10km Better than 10 Measurement Accuracy MOR 20km Better than 1596 MOR 30km Better than 2096 1 Identifies Fog or Haze Precipitation Absent Obstruction to vision E uan 2 Identifies Fog in Presence of Precipitation Table 6 1 Visibility measurement capabilities 6 5 Precipitation Measurements 6 5 Precipitation Measurement Sensitivity The sensor identifies
91. wever the connectors can accommodate wires from 20AWG down to 26AWG 0 5 to 0 13mm of solid or stranded construction Note For RS232 data configuration cable lengths above 6m will not work reliably at high baud rates It is strongly recommended that baud rates no higher than 4800 are used for cable lengths up to 25m 1 2 2 Cable Glands There are two connecting areas within the instrument one for the DC power and communications and one for the zero volts relay connections These relay connections are separate to retain the necessary isolation required for the 230V AC switching capability 2 small cable glands for cables between 3 5 to 7 00mm diameter 2 larger glands for cables between 4 5 to 10mm diameter Figure 1 2 Cable Glands STEP 2 Electrical connections 3 Biral Sensor Set up aA AHS Section 1 1 2 3 To assist in this four cable glands are provided see Figure 1 2 the 2 small cable glands are for cables between 3 5 to 7 00mm diameter the 2 larger glands are for cable between 4 5 to 10mm diameter Any or all of these glands can be used The DC power supply can be separated from the signal connection cable or a single cable can be used for all required connections If the fault or alarm relays are being used to switch mains voltages it will be necessary to use cables approved for mains use for these connections which will in general require to be separated from the communications ca
92. y 40 Standard Operating Data Message for the SWS 250 Biral Section 2 gt Standard Operating Data NUMBER CODE MEANING 67 RASN Rain or Drizzle and Snow slight 68 RASN Rain or Drizzle and Snow moderate 68 RASN Rain or Drizzle and Snow heavy 71 SN Snow slight 72 SN Snow moderate 73 SN Snow heavy 74 PL Ice Pellets slight 75 PL Ice Pellets moderate 76 PL Ice Pellets heavy 77 SG Snow Grains 78 IC Ice Crystals 81 SHRA Rain Showers slight 82 SHRA Rain Showers moderate 83 SHRA Rain Showers heavy 85 SHSN Snow Showers slight 86 SHSN Snow Showers moderate 87 SHSN Snow Showers heavy 89 GR Hail 89 GS Small Hail Graupel Table 2 5 METAR codes 2 42 SWS 250 Present Weather Measurement Timing Biral For the SWS 250 only the present weather coding and the precipitation type and intensity are always calculated at one minute intervals The measurement timing command TMx will set the timing interval for all visibility related measurements but not the present weather coding or precipitation details It is recommended that this visibility timing is set to 1 minute intervals command TM60 the default value for consistency with the precipitation measurements and coding Standard Operating Data Message for the SWS 250 4l Standard Operating Data Section 2 2 5 Data Message Variations For ALS 2 For SWS sensors
93. y block labelled J12 The individual connections are labelled A to F and A to L respectively from left to right With the power removed from the supply cable connect the ve lead to J11 C and the negative lead to J11 D The negative lead 1s the internal signal ground reference point Care must be taken particularly when long power leads are used to ensure that this negative supply lead is at near ground potential If it develops more than 10V DC with respect to ground damage will be caused to the sensor NOTE If an ALS 2 ambient light sensor is being installed with the SWS sensor these two power leads are to be taken to J1 on the SWS ALS daughter board see section 1 2 8 Connecting the hood heaters optional on SWS 100 and SWS 200 The hood heaters if fitted may be used if required They are wired independently and isolated from the instrument power These should be powered from a 24V supply of either AC or DC The SWS 050 and SWS 100 will draw 24W from this source and the SWS 200 and SWS 250 will draw 36W A higher voltage should not be used as the power will increase above acceptable levels If a lower voltage is used the de icing will be less efficient The connections are J11 A for the heater supply switched and J11 B heater return See Table 1 1 Pin connections for power supply for full details Pin connections for power supply Pin Number Designation J11 A Hood Heater Supply Option 24VAC or DC J11 B H
94. yper Terminal It is suggested that these should be carried out at least every year to provide continuing confidence in the correct operation of the system User Confidence Checks 51 Biral Maintenance Procedures Section 4 43 1 Calibration Check If you wish to carry out a user confidence calibration check please follow the calibration check procedure in section 5 page 55 to ensure that the sensor calibration values are still within specified limits THIS PROCEDURE CAN ONLY BE COMPLETED IF A SUITABLE SWS CALIBRATION KIT AND PC ARE AVAILABLE 432 52 Window Monitor Checks All SWS sensors monitor the transmitter window for contamination The values measured are used to adjust the MOR value and are also used to determine when the windows should be cleaned The performance of the monitoring circuit can be checked by the following procedures Transmitter Window Monitor Step 1 Clean the transmitter window Step 2 Send the command R Step 3 Verify that the Transmitter Window Contamination field value is 00 to 02 Step 4 Insert a white card or paper in the transmitter hood that blocks and almost touches the window see Figure 4 2 Transmitter Hood with White Card Figure 4 2 Transmitter Hood with White Card Step 5 Send the command R User Confidence Checks Biral Section 4 AAA Maintenance Procedures Step 6 Verify that the Transmitter Window Cont

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