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Important Note:
Please note, this information is provided as is, and we do not provide application engineering or comprehensive
technical support. Also, we do not guarantee our station will meet the needs of your specific application. If you
have questions, they should be submitted through email and they will be answered when resources are available.
Also, although we would not do so without good reason, we reserve the right to modify our weather station design
without warning at any time.
I.
Introduction
Thank you for choosing Davis Instruments for your weather application. This document
explains the serial data protocol between the Vantage Pro or Vantage Pro2 consoles (or Envoys)
and a PC. This requires a WeatherLink for Vantage Pro data logger and connector. It is not
possible to communicate with the console without it.
Note, the serial communication between Vantage Pro and Vantage Pro2 are very similar except
in a few places noted in this document. Important differences are described in section III.
Serial communication parameters are:
8 data bits, 1 start bit, 1 stop bit, and no parity.
Default baud rate is 19200. User selectable between 1200, 2400, 4800, 9600, 14400, and 19200
baud.
The console with a WeatherLink data logger has 3 types of memory:
•
132 KB archive memory, which stores up to 2560 archive records
•
4 KB EEPROM memory, which is used for calibration numbers, station
latitude/longitude/elevation/timezone values, transmitter configuration, and Console
graph points
•
4 KB of processor memory, which is used to store the current sensor data, today’s
high/low values, and other real-time values.
This memory is not directly available to
the PC!
Commands such as LOOP, provide access to the most useful and important of
these data values.
Commands are primarily ASCII strings. Letters should be in ALL CAPS. Please note that in
some strings numeric values are in decimal, while in others are in hexadecimal.
Multi-byte binary values are generally stored and sent least significant byte first. Negative
numbers use 2's complement notation. CRC values are sent and received most significant byte
first.
II.
Differences from WeatherLink for Monitor II
1.
An expanded LOOP packet is the only way to receive the current weather data. There is
no command to get a single parameter (such as outside temperature).
2.
Similarly there is a HILOWS command to receive all of the current daily, monthly, and
yearly high/low values with corresponding dates and times.
3.
A special DMPAFT command allows you to specify the last record you have previously
downloaded so that only the records after that one are downloaded. There is no need to
