Endress+Hauser Levelflex FMP51 Operating Instructions Manual page 191

Levelflex FMP51, FMP52, FMP54 HART
Current span
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Description
Selection
Factory setting
Additional information
Endress+Hauser
Process variable
Thickness upper layer
Relative interface amplitude
1) the 0% level is defined by Empty calibration parameter (→  146)
2) The 100% level is defined by Full calibration parameter (→  147)
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
 Setup → Advanced setup → Current output 1 to 2 → Current span
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.
• 4...20 mA
• 4...20 mA NAMUR
• 4...20 mA US
• Fixed current
4...20 mA NAMUR
Meaning of the options
Option Current range for process
variable
4...20 mA 4 to 20.5 mA
4...20 mA NAMUR 3.8 to 20.5 mA
4...20 mA US 3.9 to 20.8 mA
Fixed current
• In the case of an error, the output current assumes the value defined in the Failure
mode parameter (→  192).
• 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 (→  192) = 4 mA
4 mA value
1)
0 % or the associated
linearized value
0 mV
Lower alarm signal level Upper alarm signal level
< 3.6 mA
< 3.6 mA
< 3.6 mA
Constant current, defined in the Fixed current parameter (→  192).
Operating menu
20 mA value
2)
100 % or the associated linearized value
2 000 mV
> 21.95 mA
> 21.95 mA
> 21.95 mA
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