The correlation between multiplicities in two separated rapidity windows, the so-called long-range correlation (LRC), is studied in the framework of the model with independent identical emitters. It's shown that the LRC coefficient, defined for the scaled (relative) variables, nevertheless depends on the absolute width of the forward rapidity window and does not depend on the width of the backward one. The dependence of the LRC coefficient on the forward rapidity acceptance is explicitly found with only one theoretical parameter. The preliminary comparison with ALICE 7 TeV pp collisions data shows that the multiplicity LRC in the data can be described in the framework of the suggested approach.