Acceleration Units - Omron XTRADRIVE User Manual

XtraDrive User Manual
Example:
A rotary motion system uses a motor with a 17-bit encoder. The user
wants to program the system in speed units of rpm:
17-bit encoder produces 131072[counts] per revolution.
U=131072
1[minute]=60000[ms]
T=60000
1[rpm] =
First option:
It is possible to reduce the
fraction so that both the
numerator and denominator are
smaller than 65536:
131072 / 60000 = 32768 /15000
Reduction
Pn2B4 = 32768
Pn2B5 = 0
Pn2B6 = 15000
Pn2B7 = 0
Both options are equivalent.

5.9.1.4. Acceleration Units

Use the following parameters to convert acceleration units from
[encoder counts/(10msec)
Parameter
Pn2B8
Pn2B9
Pn2BA
Pn2BB
Acceleration user units are calculated according to the formula:
1[User acceleration unit] =
where:
U - represents the number of encoder counts in one acceleration unit.
T - represents the time of acceleration unit in (10*ms)
U [ counts ] 131072 [
=
T [ ms ] 60000
2
] to [user acceleration units]:
Setting Default
Range Setting
1-65535 1
0-16383 0
1-65535 1
0-16383 0
U [ counts
2
T [( 10
5-93
Chapter 5: Parameter Settings and Functions
[
counts ]
=
Speed units ratio
Speed units ratio
[ ms ]
Second option:
Without reduction of the fraction:
High Bits = HB = Integer part of
N/65536 = Integer part of 131072
/ 65536 = 2
Low Bits = N – HB*65536 =
131072 – 2 * 65536 = 0
Pn2B4 = 0
Pn2B5 = 2
Pn2B6 = 60000
Pn2B7 = 0
Acceleration units ratio numerator
Acceleration units ratio numerator (high bits*)
Acceleration units ratio denominator
Acceleration units ratio denominator (high bits*)

] Accelerati
=

∗
2
ms ) ]  Accelerati
]
numerator
denominato r
Signal

on ratio numerator

on ratio 
denominato r