Kistler-Morse KM Weigh II - Manual (Page 56)

7-6
Chapter 7. Service
Material tracking establishes a reference
when material movement within a vessel has
become stable (rate of change is below the
threshhold) during filling and batching pro-
cesses, as shown in Figure 7-4. This refer-
ence is then used to maintain and hold
steady the outputs. When the raw voltage
falls within the Drift Limit (DLim), the cor-
rected voltage and counts remain those
associated with the reference weight. The
correction is done by the algebraic addition of
a correction offset value to the output of the
A/D converter. The maximum correction offset
is limited to the Dlim value (plus or minus).
Material tracking affects setpoints, current
output, and serial output as well as the vessel
monitoring display.
The user can utilize tracking in any of the
following combinations:
• No zero or material tracking
• Zero tracking only
• Material tracking only
• Zero tracking and material tracking
Trk has six submenus:
Win
This function sets the maximum plus or
minus offset value for zero tracking. If the
minus offset value is exceeded, the Weigh II
resets the zero calibration point. The default
value is .00 mV — at this default value, zero
tracking is turned off.
Matrl
This function turns material tracking on and
off. The default is Off.
Rate
This function sets the threshhold rate in
uV/sec for both zero and material tracking.
When the rate of change in the voltage
exceeds this value, indicating that material is
actually moving, the Weigh II stops tracking
until the rate of change again falls below this
value. The default rate is ± 5.0 uV/sec.
Dflt
This function resets the zero and material
tracking parameters to the factory-set
default values.
DLim
This function sets the maximum plus or
minus offset value for material tracking. The
default value is ± 5.00 mV.
Mon
This function is a monitor only function. It
displays the current rate of change in the
voltage.
Setpt
This menu allows you to turn the setpoint
relays on and off for test purposes. The
Weigh II displays a warning that the auto-
matic control of the setpoints assigned to the
currently selected channel is transferred to
manual control, and requests verification that
that is what you want to do.
Figure 7-4. Material Tracking Function Example — Rate of Change Less than Rate Threshhold
Starting
Voltage
DLim
Dlim
Time
mV
DLim
Corrected Voltage
Raw Voltage
DLim