Casella CEL Nomad portable weather station - Manual (Page 40)

5.5 Dynamic Data Exchange
Dynamic Data Exchange (DDE) allows one application to access data and / or
control another. The application providing the data is called the server and the
one requesting the data is the client. Online Pro acts as a server.
Online Pro allows other applications to request information from it
about the real time data it is collecting from measuring stations. This data can
then be used for calculations in a spreadsheet, included in a word processor
report, or even used to keep a web site updated. For details of how to use your
applications as DDE clients, please refer to their individual documentation.
DDE data transactions are based on a three level hierarchy, the top
level being the application (or service) name, then the topic and item names.
The Online Pro application / service name is OnlinePro (no space). It
always has available the topic information, that provides general information
about the state of the application. In addition, it has one topic for each weather
station defined in the system, with the topic name being the same as the
weather station name.
The Information Topic can be used to obtain these names. It provides
basic information about the application with the following items:
Item name Description
Realtime Gives the string “Yes” if Online Pro is
currently in real time mode, or “No” if not.
WeatherStations Gives the number of weather stations
defined in the application.
WeatherStation# Gives the name of the numbered weather
station (e.g. item WeatherStation2 gives the
name of the second weather station).
This name can then be used itself as a topic
name to request information about individual
weather stations.
# is a number between 1 and the number
returned by the WeatherStations item.
The Weather Station Topic gives the following information about the
channels on the weather stations:
Item name Description,
Channels Gives the number of channels on the
weather station,
Name# Gives the name of the channel,
Channel# Gives the latest data value of the weather
station channel.
# is a number between 1 and the number
returned by the Channels item.
Online Pro Software
Page 40 of 68
NOMAD Portable Weather Station
Users Handbook