As an interface, interface relays connect the electronic control level, for example PLC, with the level of the sensors/actuators. They perform various functions: switching of direct or alternating voltage loads with different ohmic, inductive and capacitive components, switching in the voltage range from a few mV to 250 V, switching in the current range from a few mA to 16 A, amplifying weak control signals, potential isolation of control and load circuits and signal multiplication. The CR-P series has 9 different coil voltages with 1-2 changeover contacts. Two base variants are available: standard base and logical base. Pluggable function modules such as reverse polarity protection / freewheeling diode, LED module, RC elements, overvoltage protection or time modules expand the areas of application of the pluggable PCB relays.