OK correct me if I get the question wrong.
The airplane is in the air and no AP and FD selected.To engage the AP(the criteria is no force applied on the control wheel and the stab trim AP switch is normal) you have to press either one of AP A or AP B buttons.Lets say you pressed AP B.Since each side has its own FCC, right side FD master switch(MA) will illuminate.(With one or both AP's engaged the master FCC is determined by which AP is engaged first regardless of which FD is turned on first.)So now we have AP B engaged and FD system ready to display commanded modes.But there isn't any since no mode selected and AP is in CWS mode.As you select your Vertical and Lateral modes AP will start following them,FD's will display it with vertical and horizantal bars on attitude indicator and FMA will announciate the selected modes.