Operation
40
F-FEM-DDC — User’s Guide
4.3.4
Accuracy
The error of the counter evaluation depends on many parameters like: sensor
type, sensor attribute, acquisition rate, etc.
For a detailed specification on the dependencies of these parameters please see
the F-FEM-CON advanced Operating Manual, chapter Accuracy specification of
counter input. They are valid as far they are applicable.
4.3.4.1
General about the evaluation of counter signals
One track sensors (with Track A) have a one-edge-evaluation. This means that
only the rising edges are evaluated to get the counter ticks. Asymmetric pulse
duration does not lead to fluctuating speed values. This is shown in Fig. 18:
One track sensor evaluation:
Two track sensors (with Track A and Track B) have a one-edge-evaluation too.
This means that the rising edges of Track A are used to evaluate the speed
value, and the pulse sequence (phase relation between track A and track B) is
taken to evaluate the direction of rotation (+) and to detect and eliminate invalid
spikes. This is shown in Fig. 19:
Two tracks sensor evaluation:
Fig. 18
Fig. 19
To Next Page
Loading...
