Digital input, relay output safety barrier, dry contact in the isolation zone or NAMUR-type proximity switch signal, relay contact to the safety zone through isolation output You can independently set the output and input in-phase or reverse-phase logic control through the DIP switch (default in-phase), and set to enable or disable line fault detection (by default, the line fault is the LED flashing). This product requires independent power supply, and the three terminals of input, output and power are isolated.