Burster DIGIFORCE 9311, Руководство по эксплуатации, Страница: 124 / 216

124
of 216
Exit Bottom, Top Side at which the curve exits the Y trapezoid
Possible options:
• one exit side
• more than one exit side
• no exit
6.3.3.3 Threshold
The "Threshold" graphical evaluation element can be used to calculate and monitor the point at which the
measurement curve passes through a defined X-value or Y-value. The DIGIFORCE
®
9311 classifies
"Thresholds" as two different types. The "X threshold" type is positioned at a set X-value as a vertical line
for which you can define the range of Y-values (Ymin to Ymax)
For the "Y threshold" type the situation is exactly the opposite; the threshold is fixed at a set Y-value as a
horizontal line for which you can define the range of X-values (Xmin to Xmax). You can use up to two
thresholds in one measurement program.
Thresholds provide an OK/NOK result at the end of the measurement phase. If the curve crosses the
threshold, the DIGIFORCE
®
9311 additionally calculates the coordinates of the crossover point.
Diagram 53: Examples of thresholds
Note:
The evalutation element “Threshold” is only allowed to be passed once.
The "Threshold" graphical evaluation element outputs the following results data:
Individual evaluation
or
The DIGIFORCE
®
9311 can only output the evaluation result from a single
threshold at the Fieldbus interface.
Crossing (intersection of measurement curve and threshold)
Symbol Threshold evaluation element
The DIGIFORCE
®
9311 linearly interpolates the crossing point from the
last measurement point before the threshold and the first measurement
point after the threshold.
If the DIGIFORCE
®
9311 cannot ascertain that the threshold has been
crossed, it indicates/outputs the value pair 909090/909090 and displays
"<<<>>>" on the screen.