The optionally available and retrofittable interface module IF-KE4 extends the standard USB port featured in the series EA-EL 9000 T, EA-PS 9000 T and EA-PSI 9000 T by a three-way interface front. It offers two digital interface ports, Ethernet/LAN and USB, as well as an analog interface connector as Sub-D 15-pole version. These interfaces can be used to adapt and connect the devices to a choice of analog and digital control applications.