Rockwell Automation 9329 Drive Application Software Inertia Comp Imperial Units - Manual (Page 6)

FM – Inertia Compensation
Drive Application Software – page 6 of 28
2.0 Definitions
A Function Module [FM] is a base program designed to perform a specific function (operation) in
an application. Function Modules are not complete applications and will require additional
programming to control a machine section. The additional programming required for the
application and configuration of the overall application is the responsibility of the user.
An Application Module [AM] is a complete program designed to perform a specific machine
sections application (task). Application Modules are complete programs and only require
configuration and integration in order to perform the designated tasks.
2.1 Conventions
The conventions described below are used in programming and documentation of Function
Modules and Application Modules.
1. All FM tags are program scoped.
2. All user connections to the FM are through the Jump to Sub-Routine (JSR)
instruction input and return parameters.
3. Users cannot edit Function Modules.
4. Data format
Data Type RSLogix Type Format Range Example
B = Boolean BOOL x 0 to 1 0 or 1
I = Integer INT x +/- 32767 8947
D = Double INT DINT x +/- 2097151 74364
R = Real (Float) REAL x.x +/-16777215* 3.4 / 13.0
* = Applies to single precision accuracy.
2.2 Normalized Quantities
Often a physical quantity is normalized by dividing the physical quantity by a base quantity
with the same engineering units as the physical quantity. As a result, the normalized quantity
does not have units, but is ‘expressed per-unit’. The normalized quantity has a value of 1.0
[per-unit] when the physical quantity has a value equal to the base quantity.
A good example of this is the physical quantity of motor current. The information that the
motor is drawing 40 amps has little significance. The motor nameplate states that the rated
motor current is 30 amps. The motor is drawing 133% current is significant information. In
the previous illustration the quantity of motor amps was normalized to 133%. In per unit, the
quantity is normalized to 1.33.