The LD-81 flood detector
Plug it into the IN1 input terminal (red wire) and GND (black wire). If the detector is triggered (e.g. by a water), it sends a trigger signal. If the detector goes into a stand-by condition, it sends a non-triggered signal. The LD-81 takes its power supply from the JA-81M´s circuit.
It is possible to use the LD-81 with an older type of detector, the JA-60N, for Profi systems if you insert a 4k7 resistor in series with the LD-81 between the INP (red wire) input terminals and GND (black wire).