User's Manual

HARSFEN0602
is on. Care must be taken if the smooth factor (SF) is nonzero. Upon switching from
interpolated motion to PTP or jogging, the PTP or the Jogging will start un-smoothed.
Smoothing will gradually build up. After SF milliseconds, the motion shall be fully
smoothed.
Care is required, however, when switching to the tabulated (PT and PVT) motion modes.
The PV and the PT modes should be started only when the motor is in complete stop (MS=0
or MS=1), at the exact position specified as the first point for the PT or for the PVT. If the
motor is not in complete stop at the correct starting position, the software reference shall
jump. The command to the position controller will try to catch up with the PT or the PVT
motion, using the SD acceleration – refer the section on "Stop management".
12.1.2 Comparison of the PT and the PVT interpolated modes
The following tables compare the PT and the PVT motion modes.
Feature PT PVT
Motion buffer length 1024 64
Position points in one CAN
message
2 1
Speed command calculation Automatic, by 3
rd
order
interpolation
Specified by user
Acceleration command Automatic, by 3
rd
order
interpolation
Automatic, by 3
rd
order
interpolation
Time between user data points A fixed multiple of the 1 to 255
sampling times of the controller.
Cannot be changed on the fly.
Specified by the user
independently for each motion
interval, in msec. In the range
[1,255] msec.
Cyclical motion support Yes Yes
On the fly motion
programming with hand-
shaking host protocol
Yes Yes
Table 12-2 – Tabulated Motion Difference
Feature Preferred
Long pre-programmed motions PT
Ease of use PT
Variable command sampling time PVT
Motion design independent of controller sampling
time
PVT
Synchronized, multiple axis motions PVT
Table 12-3 – Tabulated Feature Preference
12.1.3 The Idle Mode and Motion Status
After motor on, the position profiler is Idle. This means that the software position command
is fixed. The idle mode is revisited whenever a mode terminates (A PTP or a tabulated
motion is completed), or by a stop (ST) command.
The Idle mode is the only mode in which it is possible to change the parameters of the
external reference generator.
The Idle mode of the position reference generator may be identified by the MS (Motion
Status) variable. The reading of the MS variable are summarized in the following table: