Technosoft 2018
68
iPOS4808 VX Technical Reference
T – is the slow loop sampling period expressed in [s]. You can read this value in the “Advanced”
dialogue, which can be opened from the “Drive Setup”.
Step motor closed-loop control. Incremental encoder on motor
The internal speed units are motor encoder counts / (slow loop sampling period). The
correspondence with the load
speed in SI units
]
IU
[
Speed
_
Motor
T
Tr
lines
_
encoder
_
No
]
SI
[
Speed
_
Load
×
×
×
×
π
×
=
4
2
where:
No_encoder_lines – is the motor encoder number of lines per revolution
Tr – transmission ratio between the motor displacement in SI units and load displacement in SI
units
T – is the slow loop sampling period expressed in [s]. You can read this value in the “Advanced”
dialogue, which can be opened from the “Drive Setup”.
Brushless motor with sine/cosine encoder on motor
The internal speed units are interpolated encoder counts / (slow loop sampling period). The
correspondence with the load speed in SI units is:
For rotary motors:
]
IU
[
Speed
_
Motor
T
Tr
ion
Interpolat
periods
_
Enc
]
SI
[
Speed
_
Load
×
×
×
×
×
π
×
=
4
2
For linear motors:
]
IU
[
Speed
_
Motor
T
Tr
ion
Interpolat
accuracy
_
Encoder
]
SI
[
Speed
_
Load
×
×
×
=
where:
Enc_periods – is the rotary encoder number of sine/cosine periods or lines per revolution
Encoder_accuracy – is the linear encoder accuracy in [m] for one sine/cosine period
Interpolation – is the interpolation level inside an encoder period. Its a number power of 2
between 1 an 256. 1 means no interpolation
Tr – transmission ratio between the motor displacement in SI units and load displacement
in SI units
T – is the slow loop sampling period expressed in [s]. You can read this value in the
“Advanced” dialogue, which can be opened from the “Drive Setup”
6.3. Acceleration units
The internal acceleration units are internal position units / (slow loop sampling period)
2
i.e. the speed
variation over one slow loop sampling period.
Brushless / DC brushed motor with quadrature encoder on motor
The internal acceleration units are encoder counts / (slow loop sampling period)
2
. The
correspondence with the load
acceleration in SI units
is:
1
SI units for speed are [rad/s] for a rotary movement , [m/s] for a linear movement