In this paper automatic error elimination between outputs ofnidentical simple-integral plants with different initial conditions is studied, with two distinct objectives:(a)to make all identical steady-state outputs time integral of any common inputx(t);(b)to make all identical steady-state outputs track perfectly a reference, or command, inputr(t)with the use of only ONE controllerH(S)for all the n plants. In both cases the problem can be viewed as one of synchronization. Sections 3–6 of the paper are devoted to part(a)and § 7 to part(b). Achievement of objective(b)relies heavily on the results obtained for fulfilment of objective(a). Various points discussed in the text are demonstrated by means of three examples.