Can FSX generate a polarity reversal

I need to test AudioCode MP-114/FXO answer/disconnect supervision feature using polarity reversal. I’ve an asterisk box with a Digium card with one FSX module. I was wondering if I could use it. Does anybody know if such a thing is possible? I mean can a FSX module generate the polarity reversal signal when asterisk answer and hangup the line? I’ve try the following settings in zapata.conf

answeronpolarityswitch=yes
hanguponpolarityswitch=yes

signalling=fxs_ks
group=1
callgroup=1
pickupgroup=1
channel => 3-4

signalling=fxo_ks
group=2
callgroup=1
pickupgroup=1
channel => 1

the card is configured like this: 1=FXS, 2=n/a, 3=FXO, 4=FXO

ref:
bugs.digium.com/bug_view_page.php?bug_id=2847
bugs.digium.com/view.php?id=3874