Rockwell Automation 9329 Drive Application Software Inertia Comp Imperial Units - Manual (Page 9)

FM – Inertia Compensation
Drive Application Software – page 9 of 28
4.0 Functional Description
4.1 Overview
The Inertia Compensation Function Module calculates inertia and losses torque using line
speed reference as the primary input. The Inertia Compensation Function Module consists of
a program with three routines in RSLogix5000:
1. Main (Ladder)
2. JCalc (Ladder)
3. JLossComp (Function Block)
The Inertia Compensation Function Module is available in imperial units (English) and
international units (SI or metric). This reference manual describes the Imperial units version
of the Inertia Compensation Function Module.
4.1.1 Main Routine
The Main ladder routine is where the user connects user created controller tags to
the input and output program tags of the Function Module. These links are created in
the Jump to Sub-Routine (JSR) instructions. One JSR is used to call the JCalc
routine and another JSR is used to call the JLossComp routine.
4.1.2 JCalc Routine
The JCalc ladder routine calculates total reflected inertia for a center driven winder by
adding the reflected inertia of the roll (material) to the minimum empty core reflected
inertia. The strip of material extending from the roll to the adjacent drive section is
not included in the calculation.
If the Inertia Compensation Function Module is not used for a center driven winder,
the JCalc routine and corresponding JSR instruction can be deleted.
4.1.3 JLossComp Routine
The JLossComp function block routine calculates inertia torque and losses torque.
Losses torque is calculated by adding friction and windage torque. Friction torque
and windage torque are both functions of angular velocity or motor speed.
4.2 Main routine
The Main routine consists of two rungs of ladder logic programming. A rung comment briefly
describes the Input and Return (output) parameters of the JSR instructions for each routine
called. Temporary tags have been entered for each input parameter and each return
parameter. The tag names entered in the JSR’s are not declared. The user must replace
these tag names with existing project tags or create new tags. The routine will show an error
until all input and return parameters are satisfied. The input parameters may also be entered
as actual values. If an input parameter is set to a value and not a tag, the value cannot be
edited in run mode. Values entered directly in the JSR should be constants that do not
change during machine operation. Specific formatting is required for values entered directly
in the JSR.
NOTE: For Application Module users, the tags in the JSR’s are predefined and configured for
operation. No additional integration is necessary.
Data Type Format Example
B = Boolean x 0 or 1
I = Integer x 123
R = Real (Float) x.x 3.4 / 13.0