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3.6 Evaluation methods
As a universal evaluation tool, the DIGIFORCE
®
9311 provides a wide selection of configurable graphical
evaluation elements. These can be used for OK/NOK classification of a vast range of curve types.
In addition to traditional windows with defined entry and exit sides, the DIGIFORCE
®
9311 also provides
thresholds, trapezoids of type X or Y and envelopes as graphical evaluation elements. These give you the
extra flexibility you need to evaluate practically any type of signal curve.
Summary of the evaluation elements
Symbol Evaluation element Max. number
Window with configurable
entry/exit sides, online signal,
entry/exit, min/max value
3
X or Y trapezoid,
configurable entry/exit side
2
X or Y threshold,
configurable crossing
2
Envelope,
configurable entry/exit side
1
3.7 Tare function
The tare function can be used to correct static offsets on the sensor channels. For instance you can
correct a varying background load caused by a tool changeover system by running the tare function
before every measurement. You can also set a warning limit for sensors, which can be used to detect
signs of wear in good time and hence avoid any associated measurement errors. If the current measured
value exceeds the stored warning limit while the tare function is active, the DIGIFORCE
®
9311 issues the
"OUT_WARNING_TARE" warning signal.
Options for initiating the tare function
• Manually in the "Numerical test operation" menu of DigiControl PC software
• Automated trigger via the control interface (PLC I/O or Fieldbus "IN_TARE_X",
"IN_TARE_Y", "IN_TARE_X+Y")
• Automatically when a measurement starts