Collected, a.
1. Gathered together.
2. Self-possessed; calm; composed.
Shades of meaning
Fernald has no entry of its own for collected; he lists it under calm.
Where he writes about it:
Goods or money for immediate distribution are said to be collected rather than amassed. — from amass
One is composed who has subdued excited feeling; he is collected when he has every thought, feeling, or perception awake and at command. — from calm