Rockwell Automation 1395 DC Drive, 800-1250 Hp, FRN 5.XX-9.30 - Manual (Page 53)

Chapter 3
Functional Description
3-20
General Logic Description A general block diagram (software overview) of the 1395 logic is shown in
Figure 3.5. Each of the major functions has a circled reference number
assigned to it, which corresponds to the general software functional
description given in this section.
All diagrams used for the logic description in this manual use a function
block representation of the actual software function being performed.
Calibration and adjustment of the 1395 consists of changing the values of
specific parameters.
Velocity Reference Control (Circle 1)
The 1395 is capable of selecting one of 8 possible speed reference values.
The speed reference value which is selected is determined by the currently
active Logic Command Word (Parameter 150, 151, 152). Bits 0, 1 and 2 of
the logic command provide the binary data to select from 0 through 7
(which corresponds to the 8 speed reference options). Velocity Reference
is a two parameter external velocity reference expressed in Drive Units
(4096 = Base Speed). Parameter 154 supplies the whole number part,
while Parameter 153 supplies the fractional part of the external reference.
Also selectable are five different preset speeds, defined in Parameters 633
through 637. In addition, Logic Command, bits 0,1 and 2 can be used to
select the output of a MOP as the speed reference. Selecting the MOP
function output as a reference bypasses the Jog select function. The MOP
output will enter directly into the speed limit block. Parameters 649 and
650, MOP max and MOP Min speeds, are used to limit the maximum and
minimum MOP speeds that can be reached using the MOP INC and MOP
DEC function.
Bits 9 and 10 of logic command select the Jog function as the speed
reference. Two jog speeds are available; Parameter 638 represents Jog l
and Parameter 639 represents Jog 2. These jog speeds can be defined as
either forward or reverse speed references.
The selected speed reference then enters a speed limit block. The
maximum and minimum limit of the speed reference are adjustable by
changing the values of Forward Speed Limit (Parameter 608) and Reverse
Speed Limit (Parameter 607). Forward Speed Limit sets the maximum
speed reference for the forward direction, and Reverse Speed Limit sets the
maximum speed reference for the reverse direction.
Pre-Ramp Velocity Reference (Parameter 102) indicates the value of the
velocity reference that has been currently selected by the Velocity
Reference Control. Parameter 102 is also the input to the Ramp Control.
Two parameters control the accel and decel rates of the Ramp function.
Accel Time, (Parameter 651), defines the time in seconds for the output of
the Ramp to go from zero to base speed (linear beyond base speed). This
rate applies to both forward and reverse speed references. Decel Time
(Parameter 652), defines the time in seconds for the output of the Ramp to
go from base speed to zero speed reference in both the forward and reverse
directions. In addition to the Ramp function, an “S” filter function has