3URFHVVLQJF\FOHFORFN
0HDVXULQJ,QSXW72
$[LVH[WHUQDOHQFRGHU
(GJHV
0HDVXULQJLQSXW
70+LJK)HDWXUH
&%%
&31%%
'[;
&\FOLFDOO\PHDVXUHGYDOXHV
,QWKH,32F\FOHFORFN
DWOHDVW
VHUYRF\FOHFORFNV
0HDVXULQJ,QSXW72
$[LVH[WHUQDOHQFRGHU
(GJHV
'['[;;
''
&;&;
&8
0HDVXUHGYDOXHVHYHU\
VHUYRF\FOHV
Figure 5-8
Measuring input TO, measuring operation cyclic measurement (example processing cycle clock IPO, no cycle
clock scaling IPO:Servo, IPO = Servo)
Measurement process
A measurement is activated by the _enableMeasuringInputCyclic program command. The
cyclicMeasuringEnableCommand variable indicates the execution status of this command.
The control system variable indicates whether the measuring function is active. Measuring
begins on activation of the program command.
The userdefault.measurededgecyclicMode system variable is used to select which type of
edge should be acquired. Up to two edges can be measured per processing cycle of the
measuring input TO (e.g. IPO interpolation cycle clock, IPO_2 interpolation cycle clock, or
position control cycle clock).
The measured values are taken over in the measurement equipment at time Ti and placed in
the telegram to the control. After that, the measurement equipment is ready again. In the
telegram, two edges per servo can be transmitted to the control. These are provided in a buffer
and processed by the measuring input TO in its processing cycle clock.
With cyclic measuring, the state variable remains in the WAITING_FOR_TRIGGER state even
after the arrival of events, as waiting is continued for further events. Increases on the
countermeasuredvalue1/2 event counter indicate that a measurement event has occurred.
When the measurement event occurs, the measurement position is stored. After successful
measurement, the measured values are stored in the measuredValue1 and measuredValue2
system variables and can be evaluated. The measured values must be read from the user
program before they can be overwritten by a new measurement. For example, if polling is
being performed in the IPO-synchronous task, up to two edges can be evaluated per IPO cycle
clock.
Measuring Input TO - Part III
5.2 Fundamentals of Measuring Input technology object
Output Cams and Measuring Inputs
142
Function Manual, 04/2014
