PAGING WEATHER DATA USING THE WEATHERLINK TOOLBOX™ Davis Instruments has developed additional tools to communicate weather data to many standard paging systems. Using the WeatherLink data logger and the WeatherLink Toolbox software package (#7802), a user can send messages to one or many pagers, reporting either current conditions, or specially set alarms. The current weather is reported according to a set schedule set by the program’s operator.
POSTING WEATHER CONDITIONS AND DATA VIA THE INTERNET The Toolbox software package handles two essential steps in the posting of weather data to the Internet. The software first polls the data to create the text, Java and picture files, then transfers the files to a specified address or file location. The software transfers the files using a protocol known as FTP (File Transfer Protocol). In order for the transfer to be successful, the destination site must support FTP access.
Example: Typical Home Usage The Toolbox software performs the following steps to post data to the web site: 1. Read Data from the Station Reads data from the weather station Downloads archived records 2. Create Files Data file created from the WeatherLink data logger Two graphs for each sensor stored as GIF image files 3. Generate Web Page Replaces comment tags inside a HTML template with actual weather data Saves it as another file 4. Transfer Files Transfer the files to a web server using FTP.
WEATHERLINK® RADIO COMMUNICATIONS 4 Application Note INTRODUCTION The purpose of this note is to provide an overview of the alternatives available for communication of WeatherLink data and control commands between a field weather station and the base computer. The emphasis is on radio communications. COMMUNICATION OPTIONS Because the WeatherLink bus uses standard RS-232 conventions operating at 1200 or 2400 Baud, halfduplex, (see below for details) many communication modes may be used.
COMMUNICATION PROTOCOL A data transfer comprises the following sequence: 1. The master (base) station sends a control command or request for data (6 to 12 bytes, including CRC). 2. The field station responds with a single character: CRC ERROR or ACKNOWLEDGE valid request. 3. If data were requested, the field station then sends the data. Any one of six types of data transfer may be requested. Example transfers and their typical lengths: a. Read Archive Memory 32 data bytes + 2 CRC b.
the application to the FCC. In addition you may wish to use a consultant to handle the details and type the forms. We used Josie Lynch, of Professional Licensing Consultants, Inc. (see page 9). Before seeking a license you will need to know the emissions characteristic of your transmitter (see data section, page 8) and the latitude, longitude, elevation, and planned antenna height of your base station. VHF. Frequency bands of 129 to 174 MHz and 220 to 222 MHz are often used for data transmission.
from other directions. The most common form is called a Yagi-Uda or just Yagi, after its inventors. The antenna lobe, or focussed beam, lies in the direction in which the antenna boom is pointed. The Yagi antenna’s beam width is expressed in degrees of angle between the two directions at which the signal strength has fallen to –3dB compared with the center value. For example, the Davis 8.5 dB 900 MHz antenna has a beam width of 65º when vertically-polarized.
The AOM enables the modem at 5 minutes past each even-numbered hour (according to the time clock in the Console) and keeps it enabled for four minutes. When a communication is received, the modem remains enabled during the data transfer and for two minutes thereafter; no communication is interrupted. The Timer can be set to any intervals the user selects. Any radio communication in progress when the Timer switches OFF will be interrupted. (Exception: a cell-phone call will not be interrupted.
drops too low. It is suggested that communication be limited whenever the battery voltage is less than 12.5 Volts; if the voltage drops below 12.0V, it is suggested that no communication be initiated until there is reason to believe that the station has received charging sunlight for an hour or more. SITE AND SYSTEM CONSIDERATIONS This section provides a brief discussion of some of the alternatives for the physical design of the radio communications link.
SYSTEM CONFIGURATIONS Figure 1 illustrates two possible radio links. In Figure 1a, the Field Station radio is within 8 feet of the weather station console. The WeatherLink’s attached data cable plugs into the radio via an Adapter. At the Base Station the radio is connected to the computer by a 40-foot modular cable.
System Shelter. The Complete-system Shelter is designed to provide weather protection for a complete weather station, including the optional solar power regulator and battery and a radio. Figure 2 illustrates the mounting in a System Shelter of a solar-powered station with YDI radio and an Alarm Output Module providing the power conservation control. Multi-Purpose (MP) Shelter. The MP Shelter is a smaller enclosure suitable for housing a Sensor Interface and Console or a radio and its protector.
The following shelters and accessories from Davis are compatible with the above products. 7724: Complete System Shelter 7728: Multi-Purpose (MP) Shelter 7768: Small Surge-protector (SSP) Shelter 7690: Timer 7736: Alarm Output Module 7875: Short-range Modem pair 7995: Omni Antenna Mast-mount Kit SOURCES of COMMUNICATIONS EQUIPMENT and SERVICES The list below identifies just a few of the many sources of equipment and services.
SOLAR/BATTERY CHARGE BUDGET WORKSHEET CHARGE DRAIN per DAY Current ON Time (Amps) (min/hour) A. Station _____ 60 B. AOM or Timer _____ C. Radio on D. Transmit add _____ _____ DRAIN (min/day) (Amp-min) 1440 ______ ______ _____ ______ ______ ______ _____ _____ ______ ______ TOTAL DRAIN/DAY = A + B + C + D = ______ Amp-minutes CHARGE GAIN per DAY E. Solar Panel Current @ 1000 W/m2 _____ Amps F. Peak Solar Irradiance _____ Watts/m2 G. Day Length H.
REFERENCES 1. NLR Series Technical Notes. Aerotron-Repco Systems , Inc., Orlando, FL (Spread-spectrum issues) 2. Carr, Joseph. Practical Antenna Handbook, TAB Books, 1989.
MOVING WEATHER DATA FROM AN OLD PC TO A NEW PC Application Note 34 ® With WeatherLink for Windows™ INTRODUCTION To use your current WeatherLink weather station on your new PC, it will be necessary to transfer data files to the new PC. The process may seem complicated, but is straight forward when you break the process down into its basic components. This document will attempt to outline the process and the various components that may be needed.
Using the Windows File System to Move Files If you are inexperienced in using the Windows operating system, the following general guidelines should assist you in copying the necessary files. • On your old PC, insert a blank disc into your writable disc drive or plug an external USB memory drive into one of your USB ports. Note that for writable discs, a program may launch that allows you to use a “Browse” function to select which folders or files to copy.
• The following or a similar window should appear. Click on the WeatherLink folder to select it.
• Select Edit >> Copy from the menu. Right-clicking on the folder will also allow you to select the copy function. Alternatively, you can left-click your mouse on the folder and hold it down while you drag this folder to your USB drive, the drive containing your writable disc, or the network location to which you want to temporarily copy the folder.
• Insert the written disc to a disc drive or the USB drive into a USB port on the new PC, or for network transfers, open the network drive window. In most cases, a window listing the contents of your disc or USB drive should automatically appear. • Repeat a similar process as described for copying the WeatherLink folder from the old PC: select Edit >> Copy from the disc, USB drive, or network window and then Edit >> Paste in the C: drive window of your new PC.
to reinstall WeatherLink from scratch or you have a floppy disc version and lack a floppy drive on your PC, this is an option. If you have version 4.X or earlier, you can purchase an upgrade version for a reduced price: http://www.davisnet.com/weather/products/software.asp . CONNECT YOUR WEATHER STATION If you have the Serial version of WeatherLink, and your new PC has a free serial port, then your task is complete.
