Specifications

Velocity Profile Operation
Velocity Profile Applications
The velocity profile is best suited for applications which involve motion but do not require
moves to specific points. Conveyor speed control is a typical example.
The time line of signal traces below the profile indicates the order of events. Assuming the
velocity is set greater than zero, motion begins when the Start input (Y0) energizes. Since
there is no end position target, the profile is considered in progress as long as the Start input
remains active. The profile complete logical input to ladder logic (X0) correlates directly to
the Start input status when velocity profiles are in use.
While the Start input is active, the ladder program can command a velocity change by writing
a new value to the velocity register (V2323 by default). The full speed range of 40 Hz to 7
kHz is available. Notice from the drawing that there are no acceleration or deceleration ramps
between velocity updates. This is how velocity profiling works with the HSIO. However, the
ladder program can command more gradual velocity changes by incrementing or
decrementing the velocity value more slowly.
A counter or timer can be useful in creating your own acceleration/deceleration ramps. Unless
the load must do a very complex move, it is easier to let the HSIO function generate the
accel/decel ramps by selecting the trapezoidal or registration profiles instead.
Unlike the trapezoidal and registration profiles, you must specify the desired direction of
travel with velocity profiles. Load the direction select register (V2321/V2322 by default) with
8000 0000 hex for CCW direction, or 0 for CW direction.
DL05 Micro PLC User Manual, 6th Edition, Rev. C
E–39
Appendix E: High-speed Input and Pulse Output Features
1
2
3
D
E
6
7
8
9
10
11
1
1
14
A
B
C
D
Time
V
elocity
Start
Profile
Complete
Y0
SP104