MIL-ALE Decoder

General description

The MIL-ALE decoder supports FS-1045A (MIL-STD-188-141A) standard. It decodes the basic ALE word types like selective calls (caller, and the ID which is called). It also prints the content of the control and data messages in ASCII format, if needed.

The decoder searches the MIL_ALE transmission in the range of the given frequency boundaries. Also you can set the first MIL_ALE tone frequency by doubleclicking mouse on the wanted frequency position. The numeral value of the first MIL_ALE frequency tone is shown on the screen. When MIL_ALE transmission has been detected in the given range, the decoder will then lock itself to that frequency. When locked, the decoder draws the bolded blue line on the spectrum display on the currently locked frequency (blue line is drawn on the 1st tone frequency. If the decoder is not locked, then the blue line is not shown as bolded. In the locked state, the carrier frequencies are automatically monitored in the given frequency boundaries and if the carrier frequency changes, then the decoder moves to a new frequency. If 'Lock' is pressed in the user interface, then decoder will not automatically change it's frequency. ‘Reset’ resets the decoder and received text can be saved using ‘Save’. The parameters can be modified by pressing the ‘Config’ button.

 

Configuration

Pressing the ‘Config’ button opens the following configuration dialog.

 

 

Parameters:

Tone scan area

The scanned frequency range is given with two values low and high. The MIL-ALE transmission searched only inside this frequency window.

Displayed Word Types

• ·Thru present multiple direct destinations for group calls
• ·To present direct destination
• ·From identification of present transmitter
• ·Command ALE system-wide station orderwire for coordination, control, status, and special functions
• ·This Is identification of present transmitter
• ·This Was identification of present transmitter, signal and protocol termination
• ·Data extension of data field of the previous ALE word
• ·Repeat duplication of the previous preamble, with new data field

 

FFT

The FFT button opens and closes the power spectrum window. You can for example close the power spectrum window when the decoder has locked into correct frequency in order to get more space for text window

 

Save

The save button opens the log file control dialog, which is used to open or close a log file. The detector text window can be also saved into file or sent into socket.

 

Lock

The lock button locks or unlocks the decoder frequency. Decoders have the automatic frequency scanning feature. Push the lock button when you want to lock decoder into selected frequency. Push Un-Lock button when you want to release the frequency locking.

 

Reset

The reset button resets the decoder and clears the text window.