Transponder

[dhmm]

Hi,

I just completed a small module which interfaces to the Transponder, using external panels and switches to read and change the squawk code.

Testing with PS1, when I found that if I enter a code like 0444, it will be accepted, and will sent by the broker to my program as 444 instead of 0444.

So my question is:

Is this how it is supposed to work in real life ? Can an aircraft squawk to 0444 (or any 0XXX) ?

Cheers,

:-D

[Peter Lang]

Hello,

Yes it can squak 04xx, also 00xx is possible.

You must physically enter each of the four digits.


Hope this helps
Peter

[dhmm]

Thanks Peter,

So, entering 0001, or even 0000, works from ps1, but the Broker / IPC, trims all left zeros, sending 1 for 0001, 0 for 0000, which I guess have to be handled in my code.

:-D

[Jeroen Hoppenbrouwers]

Correct!

This is what would be expected for most variables. The numerical code transponder is the exception. I believe that headings also come without leading zero, which may or may not be what you expect.

Another reason for this is that in Tcl, every number starting with a zero (not zero + decimal dot, of course) is assumed to be octal. For the transponder this would be OK, but then somewhere else the display would likely revert to decimal. So I strip all leading zeroes off everything to avoid glitches.

Pass around numbers in the most standard format possible, then format them for display when needed.


Jeroen

[dhmm]

Thanks Jeroen,

I just completed that part of the program, the program handles all numbers for the Transponder, From and To PS1, include 0000.

Starting to work on the communication / radio interface to PS1 and Intercom Systems.

Cheers,

:-D