Rockwell Automation WebPak 3000 DC Drive Application Workbook Version 1.1 - Manual (Page 15)

Configuring the Speed Loop 3-5
þ
To configure the speed reference ramp:
▲
Set TRIM MODE SELECT (P.110). The choices are:
NO TRIM - Used when the drive is configured as:
• a stand-alone speed-regulated section
• a lead or master section of a process
• an inner speed loop as part of major outer control loop design.
INCREMENTAL - Depending on the polarity of the trim reference, adds or
subtracts from the speed reference a constant value that is derived from TOP
LINE SPEED (P.020).
PROPORTIONAL - Depending on the polarity of the trim reference, adds or
subtracts from the speed reference a value that varies based on the speed
reference value, as determined by
SPD SOURCE SELECT OUT (P.193).
The actual value of the signal used to trim the selected speed loop signal, after it is set
by a multiplier block, is defined as
TRIM OUTPUT (P.197). This is summed with SPD
SOURCE SELECT OUT (P.193) to become the input to the LIMIT block.
3.2.1 The LIMIT Block
The LIMIT block limits the amplitude of the line speed reference. The input to this block
is the sum of TRIM OUTPUT (P.197) and SPD SOURCE SELECT OUT (P.193). For variable
diameter applications, the minimum and maximum line speed limits are determined
from
NORM ROLL DIAMETER (P.131) and the motor minimum and maximum limits
( MINIMUM SPEED (P.003) and MAXIMUM SPEED (P.004)).
Refer to figure A.5 in Appendix A of the software manual (D2-3444) as you set up the
LIMIT block.
þ
To set up the LIMIT block:
▲
Set MINIMUM SPEED BYPASS (P.111). The choices are:
ON - Allows the drive to operate down to zero speed.
OFF - (Default) Establishes the low end of the LIMIT block to a value determined
by the section diameter.
þ If this is a constant diameter application:
▲ Set DIAMETER CALC ENABLE (P.826) to DISABLE .
Range: NO TRIM , INCREMENTAL , PROPORTIONAL P.110 =
Range: ON , OFF P.111 =
!
ATTENTION: The drive can operate at and maintain zero speed when
MINIMUM SPEED BYPASS (P.111) is set to ON . The user is responsible for
assuring safe conditions for operating personnel by providing suitable
guards, audible or visual alarms, or other devices to indicate that the
drive is operating at or near zero speed. Failure to observe this precaution
could result in severe bodily injury or loss of life.
Range: ENABLE , DISABLE P.826 =