Lika DRAW WIRE SFA-10000 Series, Руководство пользователя, Страница: 51 / 72

SFA-5000 • SFA-10000 Profibus
If Class 2 functionality = DISABLED or Scaling function control = DISABLED,
then the system uses the physical values to arrange the position information.
The
Counts per revolution
parameter allows to program a custom number of
distinguishable steps per revolution (singleturn resolution).
The custom singleturn resolution value must be less than or equal to the
physical singleturn resolution -hardware counts per revolution value- (

8,192).
Setting a value greater than allowed causes the encoder to fall into error
signalling the fault condition through the diagnostic LEDs (see on page 30).
You are allowed to set any integer value less than or equal to the Hardware
counts per revolution. However we suggest setting a value that is a power of 2
(1, 2, 4, … 2048, 4096, …). This is meant to avoid counting errors (refer also to
the “6.9 "Red Zone"” section on page 66).
Default = 8192 (min. = 1, max. = 8192)
NOTE
See some examples on setting a custom resolution on page 52.
WARNING
When you set a new value next to the
Counts per revolution
parameter, please
always check also the
Total resolution
parameter value and be sure that the
resulting number of revolutions complies with the
Hardware number of
revolutions
of the device (4,096 revolutions).
Let's suppose that our encoder is programmed as follows:
Counts per revolution
: 8192 cpr
Total resolution = 33554432
10
= 8192 (cpr) * 4096 (rev.)
Let's set a new singleturn resolution, for instance:
Counts per revolution
=
360.
If we do not change the
Total resolution
value at the same time, we will get
the following result:
Number of revolutions =
33554432 (
Total resolution
)
= 93,206.755...
360 (
Counts per revolution
)
As you can see, the encoder is required to carry out more than 93,000
revolutions, this cannot be as the hardware number of revolutions is, as stated,
4,096. When this happens, the encoder falls into an error signalling the faulty
condition through the diagnostic LEDs (see on page 30).
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