
3.16.4.2
Function
To get a weight value a power supply is applied to the bridge circuit and a differential
voltage (U
SIG
) and excitation voltage (U
SEN
) are measured. The principle of measurement
is based on that the differential voltage U
SIG
of the bridge changes with a deformation.
Thus, a relative weight value is calculated by the difference of the both voltages U
SIG
and
U
SEN
, which are measured at the same time. The resulting difference is converted to a
weight value and stored as process data in the input area.
With the exception of
differential
and
excitation voltage
the remaining values are to be
preset by the parametrization. The resulting weight value Y is determined within the
module via the following formulas:
Y
R
Relative value
U
SIG
Measured differential voltage of the measuring bridge
U
SEN
Measured excitation voltage
RO
Rated output
Y
A
Absolute value
Y
R
Relative value
NL Nominal load
SF Scale factor
Y
Resulting weight value
Y
A
Absolute value
GN Gain
TA Tara
3.16.5
Parameter data
DS - Record set for access via CPU, PROFIBUS and PROFINET
IX - Index for access via CANopen
SX - Subindex for access via EtherCAT with Index 3100h + EtherCAT-Slot
More can be found in the according manual of your bus coupler.
Due to the extensive parameter data you can use up to 8 of these modules with a
PROFIBUS slave system.
Name
Bytes
Function
Default
DS
IX
SX
DIAG_EN
1
Diagnostic interrupt *
00h
00h
3100h
01h
UEXC
1
Excitation voltage *
00h
01h
3101h
02h
CAL
2
Calibration interval *
0000
01h
3102h
03h
MEAS
1
Measurement method
23h
80h
3104h
04h
FILT
1
Filter selection
00h
80h
3105h
05h
DFCT
2
Dynamic filter change time
10h
80h
3106h
06h
DFD
2
Dynamic filter delta
20h
80h
3108h
07h
Measurement
Weight value determina-
tion
Parameters
VIPA System SLIO
Analog Input
031-1CA20 - AI 1x16(24)Bit Strain gauge (DMS) > Parameter data
HB300 | SM-AIO | | en | 17-05
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