Liquiphant FailSafe FTL8x point level switches have two relay outputs, a 4–20 mA output that connects to a failsafe switching unit with a two-channel output, safety contacts and a safety locking function. The 4–20 mA signal jumps from high to low current when the MIN or MAX point level is reached, and a permanent live signal of 0.25 Hz is superimposed on the sensor output to indicate the sensor status.