HYDAC HDA 5500 - Manual (Page 17)

Press and hold the mode button for 5 seconds to change menu settings.
Power down/up the unit while pressing both arrow keys to Free/Lock the settings.
Gauge Connections for standard 4-20ma transducer output
HDA 4475-A-XXXX-XXX HDA5500 connector X2
1-------------------7 (Input1)
2-------------------5 (AGND)