User`s manual

5-26 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
5
4.22 Follower Ramp Distance Make-Up Time.
When the Follower Ramp feature has been
selected and the follower is enabled, the following axis is ramped up to the Master velocity at the
configured
Follower Ramp Acceleration
rate when the Master Velocity is non-zero at the time
the Follower is enabled. The master counts that accumulate during acceleration of the follower
axis are stored. In this mode, the follower axis will accelerate to a velocity that exceeds the
Master Velocity in order to make up the position error that accumulated while the Follower axis
was accelerating to the Master Velocity. This make-up distance correction has a trapezoidal
velocity profile determined by the
Follower Ramp Distance Make-Up Time
and
Ramp Makeup
Acceleration
at the beginning of the correction. This mode is used when the Follower axis must
be position-and-velocity-synchronized to the Master position at the instant the Follower mode was
enabled.
If the
Follower Ramp Distance Make-Up Time
is too short then the velocity profile is a
triangular profile. If during the distance correction, velocity exceeds 80% of the velocity limit,
then the automatically calculated velocity will be clamped at 80% of the configured velocity limit.
In both cases a warning message is reported and the real distance make-up time is longer than
programmed, but the distance is still corrected properly.
Setting a
Follower Ramp Distance Make-Up Time
of 0 allows the Ramp feature to accelerate the
axis without making up any of the accumulated counts. In this instance, the Follower axis velocity
will not exceed the master velocity. For applications where the Follower axis only needs to be
synchronized to the master velocity and lost counts do not matter, set the distance make-up time =
0.
Typical velocity profile during the follower ramp cycle is shown below.
0
Time
Velocity
Follower
Disabled
Make-up
distance
Make-Up Time
master velocity
Velocity-time Profile
(Follower Enabled at t=0)
See Chapter 8, “Follower Motion, Follower Axis Acceleration Ramp Control” section, for a much
more detailed discussion of this feature.
4.23 Select Analog Output Mode.
Digital Mode only
.
For GE Fanuc digital servos, this
command lets you choose what analog signals will be sent to the Analog Output pins (pins 6 and 24) on
the four DSM faceplate connectors. The
Select Analog Output Mode
command uses a Signal Code to
specify the signal to be sent, and a Connector Code to specify the DSM connector to receive the signal.
This command is particularly useful for servo tuning. This command can be sent from the Command
registers for any axis (1-4).
Use the following structure to set up the 6-byte %AQ Immediate Command (described in Table 5-7):
•
Byte 0 contains the Select Analog Output Mode command code (47h).