Endress+Hauser Levelflex FMP55, Operating Instructions Manual, Page: 168 / 214

Operating menu Levelflex FMP55 HART
168 Hauser
Process variable 4 mA value 20 mA value
Thickness upper layer 0 %
1)
or the associated
linearized value
100 %
2)
or the associated linearized value
Relative interface amplitude 0 mV 2 000 mV
1) the 0% level is defined by Empty calibration parameter (→  130)
2) The 100% level is defined by Full calibration parameter (→  131)
It may be necessary to adjust the 4mA and 20mA values to the application (especially
in the case of the Analog output adv. diagnostics 1/2 option ).
This can be done by the following parameters:
• Expert → Output → Current output 1 to 2 → Turn down
• Expert → Output → Current output 1 to 2 → 4 mA value
• Expert → Output → Current output 1 to 2 → 20 mA value
Current span 
Navigation  Setup → Advanced setup → Current output 1 to 2 → Current span
Description Determines the current range used to transmit the measured value. ‘4…20mA’: Measured
variable: 4 …20 mA ‘4…20mA NAMUR’: Measured variable: 3.8 … 20.5 mA ‘4…20mA US’:
Measured variable: 3.9 … 20.8 mA ‘Fixed current’: Measured variable transmitted via
HART only Note: Currents below 3.6 mA or above 21.95 mA can be used to signal an
alarm.
Selection • 4...20 mA
• 4...20 mA NAMUR
• 4...20 mA US
• Fixed current
Factory setting 4...20 mA NAMUR
Additional information Meaning of the options
Option Current range for process
variable Lower alarm signal level Upper alarm signal level
4...20 mA 4 to 20.5 mA < 3.6 mA > 21.95 mA
4...20 mA NAMUR 3.8 to 20.5 mA < 3.6 mA > 21.95 mA
4...20 mA US 3.9 to 20.8 mA < 3.6 mA > 21.95 mA
Fixed current Constant current, defined in the Fixed current parameter (→  169).
• In the case of an error, the output current assumes the value defined in the Failure
mode parameter (→  169).
• If the meausred value is out of the measuring range, diagnostic message Current
output is issued.
In a HART multidrop loop only one device can use the analog current to transmit a
signal. For all other devices one must set:
• Current span = Fixed current
• Fixed current (→  169) = 4 mA