SFA-5000 • SFA-10000 DeviceNet
5.6 Parameters
1 Position
This attribute shows the current absolute position detected by the position
sensor. The output value is scaled according to the scaling attributes, see the
attribute.
WARNING
Please note that the position value issued by the encoder is expressed in pulses;
thus you have then to convert the number of pulses into a linear measuring
unit.
To convert the position value into millimetres (mm) or micrometres (µm) you
have to multiply the number of information by the linear resolution of the
encoder expressed in millimetres or micrometres.
To know the linear resolution of the encoder please consider that
the stroke
per turn of the drum is 200 mm
.
The linear resolution results from the following calculation:
Linear resolution
=
Stroke per turn of the drum
Singleturn resolution cpr
If you want to know the linear position value you will need to multiply the
transmitted position value by the linear resolution.
Linear position value
= transmitted position * linear resolution
NOTE
Please note that the encoder's linear resolution can be read also in the order
code next to the rotary resolution. Refer to the product datasheet.
EXAMPLE 1
Let's suppose that we are using the physical resolution of the SFA-5000-FD-
8192-PG draw-wire encoder (the
attribute = 0).
The physical singleturn resolution of the measuring device is 8,192 cpr (= 0.024
mm, see the order code in the product datasheet).
As stated, the linear resolution results from the following calculation:
Linear resolution
=
Stroke per turn of the drum
Singleturn resolution cpr
Linear resolution
=
200
= 0.024 mm = 24 µm
8,192
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