Certain AWGs can generate such a waveform. No need to keep in mind every boring detail when the manual provides a good reference. That's why an instrument with poor manual is annoying to operate, similar to that with a broken knob or mangled connector
All very true, but of limited relevance here, since we are talking about
decoding rather than
generating RS-232 signals?
Also, I note that the generator for which you attached the user manual apparently does not really support either of the critical parameters we were discussing here: Signal polarity and order of bits. One can invert the whole output signal, I assume, but then has to fudge the transmitted bit pattern by manually inverting the entered value. And likewise, one has to improvise an inverted bit order by fudging with the data byte once more -- especially annoying when it can be entered as a decimal value only.
So, while I applaud the manual for documenting these restrictuions clearly, I am not convinced by the generator itself.