Meaning of the symbols on the 3-digit display

Left display: decoder type and sync-info


Middle display; J7 open

Segments a and d

With 'real' (bit noisy signal) the 2 segments will flip or even show one state, although in-sync. Not a perfect detector...
too lowtoo highin-sync

Segments b and c

QPSK only.

Viterbi-sync. With good signal this should be stable. Doesn't matter which state.
Viterbi state

Segments e and f

QPSK only, from version 7 on

For Fengyun: Viterbi-sync Q.
Viterbi state

Not-QPSK, or version 5 and earlier.

Set by jumper J5
Integrator off/on

Right display: data buffer state; J7 open

StoppedFill 0-25%Fill 25-50%Fill 50-75%Fill 75-100%Full

Display 2,3; J7 set: Quality signal

00FFperfect qualityhigher value= lower quality;
decoder must be in-sync

Other use of display

Note: This feature is switched off, but it's a matter of software to enable (the FPGA contains the logic).

Instead of the mentioned info the display may also show elevation/azimuth or X/Y in a loop: