Rockwell Automation WebPak 3000 DC Drive Application Workbook Version 1.1 - Manual (Page 42)

6-2 WebPak 3000 DC Drive Application Workbook, Version 1.1
▲
Set DIAMETER UPDATE RATE (P.867) to specify the number of roll revolutions
between diameter updates. This is based on web thickness. Typically, thinner
webs use a higher update number.
þ For variable diameter applications (unwinds or winders), GEAR IN SPEED
(P.011) is the motor speed at TOP LINE SPEED (P.020) and EMPTY CORE
DIAMETER (P.830):
▲ Set EMPTY CORE DIAMETER (P.830).
6.2 The Diameter Calculator
Six of the inputs to the diameter calculator function block are calculated by the system:
• The absolute value of SPEED RAMP OUTPUT (P.199).
• The absolute value of SPD LOOP FEEDBACK (P.296).
• The output of the threshold function block.
• A reset diameter value determined by the status of digital input DIAMETER SELECT A
TP (P.495) (terminal 59 on the I/O Expansion board) and digital input DIAMETER
SELECT B TP (P.496) (terminal 60 on the I/O Expansion board) as shown in the
following table. P.495 and P.496 can also be asserted over the network when a
network card is installed.
•
DIAMETER / TAPER IN TP (P.192), which is the value in counts of the input after gain and
zero have been applied.
•
DIAMETER RESET TP (P.829) will reset the diameter calculator to a diameter based on
the status of DIAMETER SELECT A TP (P.495) and DIAMETER SELECT B TP (P.496). P.829
is on when digital input 62 on the I/O Expansion board is on provided that DIAMETER
RST DIN TP (P.497) is asserted.
Range: 1 to 10 REVOLUTIONS P.867 = REV
Range: 1.00 to 30.00 INCHES P.830 = INCHES
Status
Input A
(P.495)
Status
Input B
(P.496) Reset Diameter Value
ON OFF WINDER CORE DIA 1 (P.822)
OFF ON WINDER CORE DIA 2 (P.824)
ON ON WINDER CORE DIA 3 (P.825)
OFF OFF UNWIND DIAMETER IN (P.828) which is the analog signal of the
analog input diameter/taper (terminals 16, 17, and 18 on the
Regulator board) when
DIAMETER / TAPER SELECT (P.870) is set to
DIAMETER .
Important: Note that the analog signal will be maximum at
core diameter and minimum at full roll diameter.
This is consistent with the output characteristics of
a sonic roll diameter detector. When a
potentiometer is used to set diameter, the
connections should reflect maximum volts at core
and minimum volts at full roll.