Rockwell Automation 1395 Reel Tension Paster Adapter - Manual (Page 14)

Publication 1395-RTP-5.1 - September 1997
2-2 Description of Operation
The press speed is measured with a magnetic pickup and fed into the
Digital Reference Adapter Board on the Drive. This signal serves as
the basic speed reference for the unwind belts. The press speed signal
is linked to the Drive Velocity Reference (Parameters 153 and 154)
and sent through the Drive Ramp Control.
The dancer input is fed into the analog input channel on the Drive and
linked to the Process Trim Reference (Parameter 161) and sent
through the Process Trim Control.
The output of the ramp control is summed with the output of the
process trim to obtain the final velocity reference.
The position of the dancer is continuously monitored, in all Normal
Run Modes, so that if a web break occurs, the motor controller will
regenerate to zero speed under current limit control. The Drive Permit
input will remain present for 15 seconds after zero speed is reached,
keeping the Main Contactor closed. At the end of 15 seconds, the
Drive Permit input drops out causing the Main Contactor to open and
the Drive will turn off. (See Mode 10.)
Mode 2
PASTE CYCLE (Motor controller follows press speed with no dancer
trim)
When the “Tension Remove” input is received, the belts are removed
from the expiring roll and the dancer trim is turned OFF; hence, the
motor controller follows press speed only. At this point, the Goss core
brake has control of the expiring roll.
Mode 3
DECEL CYCLE (Decelerate under ramp control: 2 seconds after
initiating a paste.)
After 2 seconds, determined by Parameter 580, after receiving the
“Tension Remove” signal, the press speed reference is removed and
the Drive velocity reference is set to zero (preset speed 3 with a value
of zero RPM). This will ramp the Drive down to zero speed with the
main contactor remaining energized and the Drive active. The ramp
rate is set by Drive Parameter 652.
At this point, the turret indexes and a new roll of paper is positioned
under the raised belts. When the new roll is in position, the belts may
be lowered.
Mode 4
ACCEL CYCLE (The belts accelerate a new roll of paper to speed
match with the press.)
When the “Accel” signal is received, the press speed reference is once
again used as the velocity reference for the Drive. The belts ramp up
to the press speed. The accel rate is set by Drive Parameter 651.