Reading the pay chart
Find your grade in the left column and your years-of-service step across the top. The highlighted cell is your monthly basic pay before taxes. Most members also draw BAH and BAS, which are not taxed — for a typical E-5 or O-3 those allowances are a third or more of monthly cash.
Pay on TDY
Basic pay, BAH and BAS all continue while you're on temporary duty. Per diem is paid in addition to cover lodging and meals at the TDY location — see the per diem guide for how reimbursement works and why a crashpad at or below the lodging rate is effectively free.