Rockwell Automation WebPak 3000 DC Drive Application Workbook Version 1.1 - Manual (Page 87)

Using the WebPak 3000 Drive for Web Applications: The Basics A-9
A representative transfer sequence follows:
• The outgoing full roll is indexed to the transfer position, which also places the
incoming empty core in position. Current memory could be applied to the outgoing
roll during indexing to minimize tension transients.
• The incoming core is started and accelerates to surface speed match the web
speed. The correct core diameter had been entered as a one of the spindle drive’s
setup parameters.
• The enveloper arm and transfer knife mechanism are positioned around the
incoming core. If the design was bump and cut, the bump roll would be positioned at
the core.
• Knife operates.
• Outgoing roll is stopped and incoming core is switched from speed regulation to
tension regulation.
• New roll is indexed to winding position.
• The individual spindle drives have the necessary digital input logic to switch to their
required regulator modes during the transfer sequence.
All of the splice sequence logic is done external to the WebPak 3000 drives by a
separate controller. Communication between the devices is by discrete I/O or by logic
commands over a network connection.
A.3 I/O Functions
The WebPak 3000 drive provides following I/O functions:
• Digital inputs
• Digital outputs
• Analog inputs
• Analog outputs
• Frequency I/O
Each function is described in sections A.3.1 to A.3.5.
A.3.1 Digital Inputs
The following digital inputs are programmed to support the described functions. All
inputs are rated at 24 volts.
• Coast Stop - Provides a hardwired critical stop removing the motor from its power
source. If dynamic braking is provided, it can be implemented by this input.
• Section Run - Starts the drive in speed regulation mode if tension is off. If tension
has been turned on prior to initiation of section run, the drive will accelerate to run
speed, and regulation will switch from stall tension to run tension.
• Section Off - Stops the drive under controlled deceleration.
• Over/Under - Establishes the motor direction of rotation.