[Frost] Helicity for g9b?

[Michael Dugger]

Hi,

I know this has been discussed but I can't remember the details: how do we 
get the helicity information for g9b? Is it the same type of procedure as 
for g9a:

if (getbits(TGBI[0].latch1, 15,1)==1) helicity = 1;
if (getbits(TGBI[0].latch1, 15,1)==0) helicity = -1;

and then flip the sign according to run number?

If so, does anyone know how the sign is changing with respect to run 
number?

-Michael