Sensor or actuator terminal block DOK-1.5-2D. Terminal block with red and green LED's are available for optical signalling of the initiator and actuator wiring. DIK shape, three-level initiator terminal blocks. The forks of the insertion bridge can be easily loosened for bridging between non-adjacent terminal blocks. The upper level contains the feed-through connections for the signal cable which can be labelled. Unlike the DIK terminal blocks, the lower level of these output terminal blocks makes direct contact with the DIN rail and as a PE connection are marked yellow/green. Alternate wiring of an actuator followed by an initiator is easy. Because the spine of the insertion bridge can be snapped into place with the terminal block housing, all the terminal points can be wired freely and the bridge can be securely positioned. The middle level supplies the connected actuators with power.