ACS CANopen Manual
Version 20110928
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AC C E L E N S ( AC S ) C AN o p e n
1 . I n t r o d u ct i o n
This manual explains how to install and configure
the ACS gravity referenced inclinometers (suitable
for industrial, military and heavy duty applications)
with a CANopen interface. The products are fully
compliant with CANopen DS410 standards.
1.1 Accelens (ACS)
ACCELENS inclinometers sense and measure the
angle of tilt (Inclination/Slope/Elevation) of an
object with respect to the force of gravity. The
angle is measured with the relative change in
electrical capacitance.
The basic principle behind this ACS inclinometer is
a Micro-Electro-Mechanical Systems (MEMS)
sensor cell that is embedded to a fully molded
ASIC. A simplified version of the sensor consists
of two electrodes, one is fixed, and the other is
flexible (connected with spring elements). When
the inclinometer is parallel to the surface of
measurement, a corresponding capacitance is
measured. If the sensor is tilted, the flexible
electrode will change its position relative to the
fixed electrode. This results in a change of the
capacitance between the two electrodes which is
measured by the sensor cell. The change of the
capacitance is converted to a corresponding
inclination value.
The MEMS sensor cell in ACS consists of a
micromechanical structure with an array of
electrodes for better accuracy. Under the influence
of gravity, the distance between some electrodes
change and this distance can be detected by
measuring
the
capacitance
between
the
electrodes, as explained above. This technology is
available in different grades and lower grades have
entered mass markets like mobile phones or tablet
computers.
The ACS series of inclinometers are available in
two variants. First, a single axis measurement
variant with a range of 0-360° ( either clockwise or
counter-clockwise) and the other variant, a dual
axis measurement capable ACS model with a
range of ±80°.
Absolute inclinometers identify all the points of a
movement by means of an unambiguous signal.
Due to their capacity to give clear and exact values
to all inclinations positions, inclinometers have
become one of the interesting alternatives to
singleturn absolute (and incremental) encoders
and a link between the mechanical and control
systems.
Benefits of ACS:
•
Small Size and Cost Efficient
•
High Protection Class
•
High Accuracy
•
Very Robust
1.2 CANopen Interface
CANopen is based on the Controller Area Network
(CAN) that was developed by automotive
industries in the 80s and is nowadays used in
many industrial applications. The application
protocol CANopen was introduced by the multi
vendor association CAN in Automation (CiA) to
ensure a full compatibility of industrial automation
products. It is a multiple access system (maximum:
127 nodes), which means that all devices can
access the bus. These devices/nodes are the
components of the CANopen bus and in our case
the node is ACS.
