User`s manual

SECTION 7: CANOPEN DRIVE PROFILE : DS402 DS2100 User’s Manual
C27750-001 PAGE 7-21
1
2
10
1
2
1
60
60
0
=×
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
×
=
velocity unit per motor rpm
65536
65536
__
__
2 =
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
resolutionencodervelocity
resolutionencoderposition
FactorVelocity
pos and vel. resolution same
These factors are used as shown in each of the subsequent sections to scale from the units specified by the user, to
the correct internal value to be used internally in the drive. This allows the user to work in the preferred units, while
the drive implements the correct scaling.
NOTE:- Due to the fixed point nature of the factors (i.e. U32 / U32), and the 2
32
range of their resolution, position
units of radians require a scaling of a floating point number (i.e. 2π). For example, if the Position Dimensions is in
radians (i.e.
0x10), and the encoder resolution is 65536, then the Position Factor is 65536/2π. This is implemented
in fixed point, by setting the numerator to nearly it’s full numerical range of 2
32
, and setting the denominator
accordingly. :-
39.10430
411768
4294901760
2*65535)32(
65535
1
65536
==
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
×=
π U
FactorPosition
This compares to a value of 10430.37, when floating point arithmetic is used.