That depends up on two factors. First what is the operating voltage, 12VDC or 24VDC? Second is what is the gauge of wire? The following chart will show you the allowable distance based upon operating voltage and wire size.

Distance (one way) 50 ft. (15 M) 100 ft. (30 M) 200 ft. (60 M)
Wire Gauge for UNL-12 16 14 12
Wire Gauge for UNL-24 22 20 18