8-70
Drive Functions
MPH-02, MPB-02, MPD-02
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
By means of list parameters the circular velocities and velocity pulse
amplitudes are assigned to one another:
•
P-0-0438, Table of path velocities for quadrant error correction
•
P-0-0439, Table of velocity pulse for quadrant error correction
It is possible to store 20 pairs of values for velocity and pulse amplitude in
the mentioned parameters, the velocities have to be entered in ascending
order.
The velocity pulse amplitude to be assigned to a current circular velocity
is determined by means of the list parameter values:
•
Between 2 pairs of values the pulse amplitude is interpolated in linear
form, depending on the current path velocity.
•
Below the lowest path velocity the pulse amplitude is set to zero.
•
Above the highest path velocity the pulse amplitude assigned to the
highest path velocity continues to take effect.
The controller calculates the current circular velocity by means of the
current acceleration command value of the drive calculated from the
position command values. The reference radius (P-0-0436) is the basis
for calculating the path velocity.
If the drive-internal resolution of the calculated acceleration command
value is low, quadrant error correction sometimes is without effect. For
this case it is recommended to integrate the extended position command
value (
P-0-0100, Position command value extension
) in the cyclic
master communication. This extends the decimal places of the position
command value.
Note:
When using the quadrant error correction it is basically useful
to use the extended position command value on the control
side and integrate it in the cyclic master communication!
The quadrant error correction is activated by the control master by setting
the respective bit of
P-0-0435, Control word of position controller
. It is
only advantageous to use the function when a circular form is to be
machined in the part program.
The correction should be activated at the earliest one clock after the start
of circular interpolation so that the velocity pulse won’t be added when the
drive is starting. Otherwise high velocity pulses damaging the contour
could be added, due to the mostly high starting accelerations, when the
drive is starting.
For machining other contours the quadrant error correction should be
deactivated. To do this the respective bit of P-0-0435 should be contained
in the cyclic master communication and activated depending on the kind
of machining.
Note:
The quadrant error correction remains without effect when the
value "0" is contained in
P-0-0437, Velocity time range for
quadrant error correction
.
Determining the Velocity Pulse
Amplitude
Determining the Current Circular
Velocity
Activating the Quadrant Error
Correction
Courtesy
of
CMA/Flodyne/Hydradyne
▪
Motion
Control
▪
Hydraulic
▪
Pneumatic
▪
Electrical
▪
Mechanical
▪
(800)
426-5480
▪
www.cmafh.com
