1996 Monte Carlo Purge Valve/Control Question

Just bought a 1996 Monte Carlo with a 3.1 engine. On the purge valve
/control solenoid there is a vacuum line that isn't hooked up. It's the one
located toward the bottom of the solenoid. I noticed this when I was
changing spark plugs and thought that I might have accidentally pulled it
off but I couldn't find a loose vacuum line anywhere. Could someone who is
familiar with this engine please explain what vacuum lines go to this thing
and then I can track down which one is missing.
Thanks for any help.

Regards,
Dennis