USER MANUAL
STM 550 / EMSI
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ENOCEAN MULTISENSOR FOR IOT APPLICATIONS
© 2020 EnOcean | www.enocean.com F-710-017, V1.0
STM 550 / EMSI User Manual | v1.3 | September 2020 | Page 23/97
3.5
Acceleration sensor
STM 550 integrates an acceleration sensor which provides two types of data:
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Acceleration vector orientation
This allows determining the direction into which STM 550 is either accelerated
(moved) or permanently oriented (positioned relative to the earth gravity vector).
See chapter 11.2 for an example.
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Acceleration vector change
This allows determining if STM 550 is moved or shaken
The second case (acceleration vector change) can be used to determine the presence or
absence of small vibrations (acceleration vector changes). Examples use cases causing such
small vibrations include asset utilization (e.g. a motor to which STM 550 is attached is run-
ning) or asset movement (e.g. an asset to which STM 550 is attached changes its location).
If such change in acceleration is above a certain threshold then this will be reported as part
of the regular data telegram. If the acceleration exceeds this threshold for the first time,
then this will be reported immediately (wake-on-acceleration).
Figure 11 below shows the orientation of the acceleration vector relative to STM 550.
Figure 11
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Acceleration sensor orientation