MM64003a_e.doc / Feb-09
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8.
Hints for Scaling of the Unit
The scaling parameters of the unit affect the display of the actual values as well as the
associated Setpoints for the switching functions. In principle, there are two fully independent
sets of scaling parameters:
a.
Scaling parameters for frequencies and speeds
b.
Scaling parameters for counters, positions and differential positions
Where your application uses setpoints for control of speeds, you must use the speed
dimensions according to your speed scaling to enter the set speeds of the
corresponding encoder
Where your application uses positional or differential counter setpoints for control of
distances or errors, you must use the positional dimensions according to your counter
scaling to enter the setpoints of the corresponding encoder
8.1.
Speed Scaling
Internally, the unit measures all speed-related values as a frequency with a resolution of
0.1 Hz. This numeric value is used as a basis for all further calculations.
When e.g. the actual frequency of an encoder is 1.5 kHz, the unit would internally use a value
of 15 000.
You are free to attach any other dimensions to your speed measurements (e.g. RPM, m/min,
miles/h etc.) by corresponding setting of the parameters F06.080 to F06.082 (encoder 1) or
F07.095 to F07.097 (encoder 2)
Example: a frequency of 1.5 kHz on encoder input 1 should be converted to a speed scaling of
67.0 m/min. This means the internal value of „15 000“ must be converted to a value of „670“
(display of 67.0 requires a result of 670 which appears as 67.0 when the decimal point is
switched on).
It is easy to understand that we only need to divide the basic frequency value by 15000, then
multiply it again by 670 (F06.80 = 670 and F06.81 = 15 000). The Offset (F06.82) remains set to 0
(because frequency = 0 means at the same time speed = 0).
Speed [ 1/10 m/min ] = f [ 1/10 Hz ] x
15 000
670
(F06.80)
(F06.81)
After setting the decimal point (F06.83 = 1), the speed display and all Set Speeds related to
encoder 1 are set to a format xxx.x m/min (Set Speed 1.1, Set Speed 1.2 und Set Speed 1). This
speed scaling will neither affect the position counters nor the differential counter of the unit.
Summary of Contents for MM 640
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