
Filter level
Limit frequency
Filter constant
Rise time 10-90% [s]
(typ.)
06h: IIR5
8Hz
a
0
= 3.91x10
-3
0.056
07h: IIR6
2Hz
a
0
= 977x10
-6
0.225
08h: IIR7
0.5Hz
a
0
= 244x10
-6
0.9
09h: IIR8
0.1Hz
a
0
= 61.0x10
-6
3.6
Prevent overriding the filter
By a brief activation of Input Freeze in the command byte DMS_CMD
pulses, e.g. caused by a filling procedure can be prevented, which would
override the filter unnecessarily. As soon as Input Freeze is activated, no
measurement values are passed to the digital filter.
Via the FILT parameter you can de-activate the filter function or you can specify a fix filter
level (IIR1...IIR8).
3.16.7
Calibration
Please use for the calibration the software filter IR8 (slow). The following steps are neces-
sary for the calibration:
1.
Specify in the parametrization the
Reference load
RL. The
Reference load
must be
at least 20% of the
Nominal load
.
2.
Operate the balance without load.
3.
As soon as a stable value is shown, bit 6 (set zero point) in the command byte
DMS_CMD
is to set.
4.
Apply the balance with the reference load. As soon as a stable value is shown, bit 7
(set reference point) in the command byte
DMS_CMD
is to set.
5.
Set bit 1 (store adjustment) in the command byte
DMS_CMD
.
ð
As soon as the adjustment data were stored successfully, the module measures
with these parameters. The adjustment data remain even after a power loss
condition and can be deleted (delete adjustment) via bit 2. The adjustment data
can be rewritten only every 120 seconds.
3.16.8
Steady state detection
n
If the measured value is within the range of values
SST
longer than the the time
interval
SSW
, then bit 1 (steady state active) of the status word DMS_STAT is set.
The current measured value is used as the starting point for the range of values and
the steady state timer is started.
n
If the measured value remains within
SST
over the period
SSW
, the steady-state bit
is set.
n
If the tolerance range
SST
is exceeded, the last measured value is used as starting
point and the time is newly started.
n
The values
SSW
and
SST
can be specified by the parametrization.
Static IIR filter
Proceeding
Functionality
VIPA System SLIO
Analog Input
031-1CA20 - AI 1x16(24)Bit Strain gauge (DMS) > Steady state detection
HB300 | SM-AIO | | en | 17-05
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