Heinrichs Messtechnik GmbH
Supplement manual Foundation Fieldbus
Page
9 of 10
5.3
Analog Input Function Block (AI)
The UMC3-FF contains 4 AI blocks:
-
Flow (mass or volume flow, depending on the unit selected in the transducer block)
-
Density (in case the density measurement is calibrated and switched on or if a fixed density is
preset)
-
Temperature
-
Forward totalizer (internal totalizer of the UMC3 transmitter). This totalizer accumulates mass
flow or volume flow depending of the totalizer unit selected in the transducer block.
The following parameters have to be set in order to map the measured value at the input of the AI to
it’s output (default setting when device is shipped)
CHANNEL:
“measured value“
L_TYPE:
“Indirect“
XD-SCALE
EU_100 corresponds with upper range value
EU_0 = 0
The “units index“ must be set identical to the unit selected in the transducer block.
If output of AI shall be identically to its input (scaling = 1) following parameters have to be set to:
OUT-SCALE equal to XD-SCALE.
Any unit of OUT value can be selected. There is no conversion between units (e. g. kg -> t) supported
LOW CUT (low flow cut off):
The low flow cutoff is given in % related to the OUT-SCALE.
When going below this limit the output will be set to zero. In order to activate the low flow cut off
additionally the parameter IO_OPTS has to be set to “low cutoff“. The setting of the low flow cut
off does not affect the reading of the mass flow in the local display. It also does not affect the
totalizer. The Default setting is 1%. Please regard that the low flow cutoff will avoid negative
readings.
The parameters for monitoring the limits will not be set by default.
PV_FTIME
(Damping):
The damping is used to smooth the measured value. Set to 0 seconds by default. The damping value
set by the local panel is still active even if this parameter is set zero.
