Fayat Group Dynapac SCREED-CONTROL, Руководство по эксплуатации

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15 Definitions/Glossary
164
15 Definitions/Glossary
Definition Definition
Actual value The actual value measured by a sensor, e.g. the distance of a gap
sensor to the reference point or the inclination measured by a slope
sensor.
Actuator Converts control signals into (usually) mechanical work, i.e.
movement; e.g. a valve that opens or closes.
Calibration to zero The value "0.0" is allocated to the current measured value which at
the same time is taken to be the nominal value for control.
CAN bus The CAN bus (
C
ontroller
A
rea
N
etwork) is a system for serial data
transfer. It was developed for networking controllers in motor
vehicles in order to reduce the cable harnesses (up to 2 km per
vehicle) and make data transfer more secure.
Control variance Difference between nominal and actual value.
When making adjustments, the controller moves the actuator so
that the measured value of the sensor (actual value)
corresponds with the stipulated value (nominal value).
Dead band A symmetrical area around the working point where there is no
activation of the output. It is used to achieve stable behaviour of the
screed in the working point.
Max. pulse Activation pulse defining the maximum permitted working speed of
a hydraulic cylinder.
Min. pulse Minimum activation pulse necessary to move a hydraulic cylinder
over the smallest possible distance.
Nominal value The target variable entered or specified by the user which has been
reached and should be sustained by a control circuit.
Offset A constant systematic error of a variable or measured value (e.g.
when the digital slope sensor cannot be fitted absolutely parallel to
the lower edge of the screen).
Prop band Area above and below the dead band with "regulated" activation of
the output. The pulse length depends on the control variance.
Working point Point (gap or inclination) where the actual value and the nominal
value are the same and no adjustment takes place.