Table of Contents - TG Drives

68
Pg, Profile generator
PG, PROFILE GENERATOR
Group Group
No
Description
EXTENDED REGISTER GROUPS
Pg 4 Profile Generator. The profile generator calculates the
velocity profiles used for trapezoidal movements.
GENERAL
The Profile generator (Pg) group controls the basic motion function. Any movement
can be defined as segments of acceleration, constant speed and deceleration and
the Pg function accomplishes this.
This function produces so-called Trapezoidal profiles which are movements with
three phases, acceleration, constant speed and deceleration. The target position is
reached with the speed = 0.
When the Connect instruction is used on this group and for instance the regulator,
the values are taken from the same servo cycle. The old DMC 2 showed values one
servo cycle ahead for the Profile group.
FUNCTION
Pg.APos
Pg.ASpeed
Pg.Acc
Pg.Ret
Pg.Decel
Pg.RSlope
Pg.PosSpeed
Pg.Rdy
The profile generator outputs command values for speed and
position with 1 ms update rate. These values are used by the
regulator as input values. The outputs are PG.APos and Pg.Aspeed
where PG.APos is the integrated value of Pg.ASpeed.
To get any output, the Pg.Acc must be set to some value > 0 and
that value will be used as the acceleration limit.
Pg.Ret (or. Decel) is used only to determine when it is time to start
the deceleration phase and from that point on the actual deceleration
is calculated each ms so that the speed will be zero when the
position target is reached.
The deceleration phase can be smoothed by setting the value of
Pg.RSlope > 0. This will provide an exponential velocity change
instead of a linear one during deceleration. When Pg.RSlope > 0 the
deceleration will initially be higher than the value stated in the
parameter Pg.Ret.
The Pg.PosSpeed determines the top speed of the profiles.
The bit register Pg.Rdy reports when the profile is finished.
The profile generator can also take values from an array specifying segments of
acceleration and duration time. This makes it possible to define customized
profiles. In this case none of the other parameters are involved. The array can
have up to 1000 segments.
RELATED ITEMS
Pos Abs
Pos Rel
Move to the absolute position .
Move to the absolute position ( + Pg.Apos)
User's Manual 5.1 Inmotion Technologies AB
Doc. No.9032 0027 01 (B), Rev. 11.07.2001