Detailed Drive Operation; Accel Time - Allen-Bradley PowerFlex 70 Reference Manual

Accel Time

Detailed Drive Operation

This chapter explains PowerFlex drive functions in detail. Explanations are
organized alphabetically by topic. Refer to the Table of Contents for a listing of
topics.
[Accel Time 1, 2]
The Accel Time parameters set the rate at which the drive ramps up its output
frequency after a Start command or during an increase in command frequency
(speed change). The rate established is the result of the programmed Accel Time
and the Minimum and Maximum Frequency, as follows:
Maximum Speed
Accel Time
Two accel times exist to allow the user to change acceleration rates "on the fly" via
PLC command or digital input. The selection is made by programming [Accel
Time 1] & [Accel Time 2] and then using one of the digital inputs ([Digital Inx
Sel]) programmed as "Accel 2" (see
a PLC is used, manipulate the bits of the command word as shown below.
0 0 0 0 1 1 1 0 1 0
15 14 13 12 11 10 9 8 7 6
Bit #
0 0 0 1 Accel 1
0 0 1 0 Accel 2
0 1 0 0 Decel 1
1 0 0 0 Decel 2
The effectiveness of these bits or digital inputs can be affected by [Accel Mask].
See Masks on page 113 for more information.
Times are adjustable in 0.1 second increments from 0.0 seconds to 3600.0
seconds.
In its factory default condition, when no accel select inputs are closed and no
accel time bits are "1, " the default acceleration time is Accel Time 1 and the rate is
determined as above.
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
= Accel Rate (Hz./sec.)
Table 9 for further information). However, if
1 = Condition True
0 0 1 1 0 0
0 = Condition False
5 4 3 2 1 0
x = Reserved
2
Chapter
11