Dynamic Data Exchange (DDE) Specifications for Nova for Windows

Nova for Windows (NfW), both 16- and 32-bit versions, can act as a DDE server.
The program can supply satellite tracking and range-rate data to any standard
DDE client application; this information may be used to implement customized
interfaces for antenna tracking or radio tuning.

Following are general specification for DDE as implemented in NfW.  Note that all
names and strings are case sensitive.

DDE Server name  : NFW_SERVER
DDE conversation : NFW_DATA

DDE is initiated when the server (NfW) receives the string 'TUNE ON'.
The AutoTracking Status Box must be displayed in NfW although autotracking does
not have to be activated.

When DDE has been activated, a single string containing the following data are 
"transmitted" 2-10 times per second (depending on CPU speed and loading) via 
DDE:

SatName AZ:Azimuth EL:Elevation RR:RangeRate

where
     SatName   = the current autotracking satellite name as derived from the NfW
                 database, maximum 12 characters;
     Azimuth   = current satellite azimuth, 0.1 degree precision, no sign;
     Elevation = current satellite elevation, 0.1 degree precision, signed;
     RangeRate = satellite rate of change of distance from the observer
                 expressed as a signed floating point number in units of
                 1/the speed of light.

One space separates each field; no space after (:) labels.  Make no assumptions
about field lengths or total string length.  Values are referred to the current
AutoTracking Observer in NfW at the current UTC time and date.

Sample DDE string:
Mir AZ:116.4 EL:-21.0 RR:-1.4396996895

DopplerHz = -FreqHz * RR * (1.0/299792.458)

  

M.R. Owen
Northern Lights Software Associates
nlsa@nlsa.com
http://www.nlsa.com
12-18-97