Endress+Hauser Liquiphant FTL33 Operating Instructions Manual page 22

Electrical connection
When both outputs are connected, the MIN and MAX outputs assume opposite states (XOR)
when the device is operating fault-free. In the event of an alarm condition or a line break,
both outputs are de-energized.
Connection for function monitoring using XOR operation
2 1
3 4
0.5A
K1 K2
L– L+
Wire colors for M12 plug:
• 1 = BN (brown)
• 2 = WT (white)
• 3 = BU (blue)
• 4 = BK (black)
Symbols
K1/K2
Connection with valve plug
Depending on the assignment of the connector or the wiring of the cable, the device works in
either the MAX or MIN operating mode.
22
Max output
Sensor covered
Min output
Max output
Sensor not covered
Min output
Fault
Description
LED lit
LED not lit
Fault or warning
External load
Yellow LED (ye)
1 2
1 4
1 2
1 1 4
1 2
1 1 4
Liquiphant FTL33
LED red (rd)
Endress+Hauser