Diagnosis; Signal Quality - Balluff BML-S1G0 Série Notice D'utilisation

BML-S1G0-_7_ _-M5EG-_0-_ _
Absolute magnetic encoder system
7

Diagnosis

7.1

Signal quality

The position data is compiled from over 30 magnetic field
sensors. Different parameters such as distance, side
offset, ambient temperature, angle to the magnetic tape,
and external magnetic fields have a direct effect on the
measuring accuracy. The measuring accuracy is given as
signal quality by using a plausibility check.
To perform the plausibility check, the sensor head must
be moved over the tape with a speed of <1 m/s. If no
value can be determined (speed > 1 m/s or direction of
movement reversed), then the signal quality is 15. If the
measurement is successful, the signal quality has a value
between 0 and 14.
Fig. 7-1: Position over time
Fig. 7-3: Position over time for a simulated magnetic tape problem
In Fig. 7-1 and Fig. 7-2 the sensor head is located within
the working range. In Fig. 7-3 and Fig. 7-4 the magnetic
tape is sometimes covered by a magnetizable material
between positions 50,000 and 70,000. There, the signal
quality is reduced compared to the intact magnetic tape,
even though the position can still be reliably detected.
The greater the signal quality, the better the quality of the
internal signals. Values down to 1 are sufficient.
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Fig. 7-2: Signal quality over travel
Fig. 7-4: Signal quality over the travel for a simulated
magnetic tape problem
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