What were the military duties of ranked officers?

The military duties of ranked officers were (and continue to be) to follow orders from superiors and provide leadership to those in their command. There are many other duties. Managing personnel, keeping records, ensuring the basic needs of the people in their command are some. Accessing supplies, maintaining communications, maintaining order and discipline, and responding to emergencies are others. An officer has a great variety of duties depending on circumstances - one officer may sit at a desk managing recruiting or funerals; another may be a medical doctor; and another might be a front line soldier under fire with his troops.