The R-series plug-in module 28 V-IN is a 2-channel digital input module for galvanic isolated detection of voltage signals. The input statuses are shown using light diodes. Both input signals relate to a joint IN_- potential and are galvanically isolated from the module's power supply. Both output signals are not only galvanically isolated from the power supply but also from each other. The outputs are related to a defined potential of the external interface on the master module (+5 V interface, DGND).