Triggering Data Recording; Triggering Data Output; Trigger Time Difference - MICRO-EPSILON interferoMETER Operating Instructions Manual

Advanced Settings
Start value Step size
Fig. 50 Definition of terms for encoder triggering
i
Within the step size there are no readings. Keep this, if measurement averaging is used.
7.2.8.2

Triggering Data Recording

The current array signal is only processed and measured values are calculated from it after a valid trigger event. After
possible signal processing (e.g., average), the measured value data are then prepared for output via a digital or analog
interface. When calculating averages, measured values immediately before the trigger event cannot be included; instead
older measured values are used, which had been entered during previous trigger events.
7.2.8.3

Triggering Data Output

Measurement values are calculated continuously and independently of the trigger event. A trigger event simply triggers
the value output via a digital or an analog interface.
Therefore, any values measured immediately before the trigger event are included in calculating mean values (averages)
or statistics.
The measured value at the time of the trigger event is output with a delay.
7.2.8.4

Trigger Time Difference

Since the exposure time is not started directly by the trigger input, the respective time difference to the measurement cy-
cle can be output. This measured value can, for example serve to accurately assign measurements to one place, when
measuring objects are scanned at a constant speed and when each track starts with a trigger.
The time from the start of the cycle until the trigger event is defined as a trigger time difference. The output of the time
determined occurs 5 cycles later, due to the internal processing.
Exposure
N N+1
Input TrigIn
Start
Trigger time
difference
Fig. 51 Definition of the trigger time difference
i
The start of the cycle does not mean the start of the exposure time. There is only a fixed difference of 100 ns be-
tween the start of the cycle and the end of the exposure time.
IMS5x00
Lower limit
Trigger points
N+2
Measurement output
Upper limit
Readings encoder
N+3 N+4 N+5
analog N
digital N +
Trigger time
difference
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