Rockwell Automation WebPak 3000 DC Drive Application Workbook Version 1.1 - Manual (Page 97)

Glossary Glossary-5
sequencing - Logic that controls the state of the drive (running, stopped, etc.). See
chapter 3 in the drive software manual (D2-3444) for more information.
slack - Lacking in usual or normal firmness and steadiness; not tight or taut.
speed loop - An outer control loop using a speed-sensing device to provide speed
feedback for comparison to the speed reference.
stall tension - A function that is used to hold a reduced level of tension on the web
during a stall condition.
system inertia - See JBAR
top line speed - The maximum line speed in feet per minute.
taper tension - A function used in winding applications to build a uniformly wound roll.
As the roll builds, the tension is steadily reduced to avoid a condition where the
material being wound begins to collapse upon itself. That taper function will modify the
set tension (tension used at empty core) using either a hyperbolic or linear function.
See figure 1
trim - A function in which a portion of field current is fed back to a regulator circuit that
compensates for line-voltage variances and field-resistance changes caused by motor
warm-up.
type 3 position regulator - A feature that eliminates the need to provide a motor
speed feedback device by bypassing the speed loop.
underwind - See overwind
vernier - A small auxiliary device used with a main device to obtain fine adjustment.
vernier control - A method of improving resolution. The amount of vernier control is
expressed as either the percent of the total operating range or of the actual operating
value, whichever is appropriate to the circuit in use.
Figure 1 - Torque Taper Function
T a p e r F u n c tio n
0 . 0 0
0 . 1 0
0 . 2 0
0 . 3 0
0 . 4 0
0 . 5 0
0 . 6 0
0 . 7 0
0 . 8 0
0 . 9 0
1 . 0 0
1 5 9
13 17 21 25 29 33 37 41 45
D i a m e te r
TaperPcnt
H y p e r
L in e a r