Rockwell Automation WebPak 3000 DC Drive Application Workbook Version 1.1 - Manual (Page 18)

3-8 WebPak 3000 DC Drive Application Workbook, Version 1.1
3.2.2 The S-CURVE Block
The output of the LIMIT block is the input to the S - CURVE block. SPEED RAMP BYPASS
(P.112) controls the output of the S - CURVE block. Refer to figure A.5 in Appendix A of
the software manual (D2-3444).
þ
To set up the S - CURVE block:
▲
Set SPEED RAMP BYPASS (P.112). The choices are:
ON - Bypasses the S - CURVE block, and the output of the LIMIT block is used as
the value of SPEED RAMP OUTPUT (P.199). (This value can also be read as
SPEED RAMP INPUT TP (P.198)).
Note that setting SPEED RAMP BYPASS to ON will negate the use of inertia
compensation when INERTIA COMP SELECT (P.221) is set to CALCULATOR . To
use the drive’s on-board programmed inertia compensation function, P.112
must be set to
OFF .
OFF - The output of the S - CURVE block is used as the value of SPEED RAMP
OUTPUT (P.199).
þ If SPEED RAMP BYPASS (P.112) = OFF :
▲ Set S - CURVE ROUNDING (P.014) to specify the smoothing of the S - CURVE
block output.
The range is 0 to 50%. A 0% setting results in a linear ramp function. A
50% setting results in the entire ramp being smoothed 50% at the
beginning and 50% at the end, which extends the ramp time.
▲
Set STOP MODE SELECT (P.114). The choices are:
RAMP - RAMP STOP DECEL TIME (P.018) or DECELERATION TIME (P.002) is used.
Note that if the trim mode previously selected in TRIM MODE SELECT (P.110) is
PROPORTIONAL , under a ramp stop configuration the ramp time will be
modified in the same way as the acceleration ramp time.
COAST / DB - If a coast stop or a dynamic braking stop is initiated, the main
contactor will open immediately, and the drive will coast or dynamically brake
to zero speed.
CURRENT LIMIT - All deceleration ramps are bypassed.
þ If STOP MODE SELECT (P.114) = RAMP , then STOP DECEL SELECT (P.122)
must be set to P.002 or P.018:
▲ Set STOP DECEL SELECT (P.122) to specify which deceleration time will
be used for a ramp stop sequence. The ramp deceleration time for
stopping can be set independent of the normal running deceleration
ramp.
Note that if an external ramped reference is used, the deceleration rate
for the internal speed ramp (
S - CURVE block) should be set so that it is
faster than the deceleration rate of the external speed reference ramp.
Range: ON , OFF P.112 =
Range: 0 to 50% P.014 = %
Range: RAMP , COAST / DB , CURRENT LIMIT P.114 =