Definitions, Conventions, Normalized quantities – Rockwell Automation 9329 Drive Application Software Positioning Point to Point User Manual

Page 3

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Quick Start – Positioning (Pt to Pt)

Drive Application Software – page 3 of 10

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 with Function Modules and
additional programming to perform a specific machine sections application (task). Application
Modules are complete programs, only requiring configuration and integration to perform the
designated tasks.

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.

Normalized Quantities


A physical quantity is typically 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 without the knowledge of the specific
motor size and current rating. 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.


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