Hi Nev,
that seems odd.
I have the FA-2 and FA-3 and both output a string of measurement for each gate period.
There might be different firmware versions for at least the FA-2, as we have reports of different output string format (mentioned in this thread).
If you use Chan 1, make sure, that there actually is an inputsignal, otherwise it might not output a measurement.
Chan 2 produces "measurements" without an input signal.
If the gatetime is 10 sec, you have to wait up to 10 seconds for the string to appear (I know that this is obvious, but fell into this trap myself, because I thougt, that I set a shorter gate time)
Sorry, I cant help with undocumented commands.
Chris