Exploring Elementary
Data Types
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Level 1: Logix - On Demand
Exploring Elementary Data Types
Before You Begin
About this Lab
Many complex data structures within the Studio 5000 Logix Designer® application may be
employed to simplify integration of hardware and use of advanced instructions. However, when
we drill down into these structures, we find that their various elements are of data types from the
list of elementary data types. In this lab you will:

Explore elementary data types
This lab takes approximately 15 minutes to complete.
Hardware
To complete this lab, you will require the following hardware:

PC-based programming workstation with access to the RAcbi learning environment
Software
To complete this lab, you will require the following software:

Studio 5000 Logix Designer version 32
Files
To complete this lab, you will require the following files:

Machine_1_Lab11.ACD
Setup
To complete this lab, you will need to perform the following setup procedure:
1.
Log on to your instance of the RAcbi learning environment.
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Exploring Elementary Data Types
Level 1: Logix - On Demand
Add Local Hardware Modules
For our fundamental logic, we tend to use tags of the Boolean data type because they align with
the data requirements of bit-level instructions. However, in addition to the Boolean data type,
there are several other elementary data types with which we should be familiar. In this section of
the lab, you will experiment with the various elementary data types to gain a better
understanding of their use and limitations.
1.
If you have completed all labs up to this point in the Level 1: Logix - On Demand course,
then you may continue using your Machine_1.ACD file from previous labs:
a.
Open the Studio 5000® environment.
b.
Under Recent Projects, select your Machine_1 project:
1.b.
2.
If you have NOT completed all labs up to this point in the Level 1: Logix - On Demand
course (e.g., you are just doing this individual lab as a refresher), then open the starting
file for this lab:
a.
Use the shortcut
on the desktop of your instance of the RAcbi learning
environment to open the LabFiles.
b.
Open the Machine_1_Lab11.ACD file.
The help documentation that is installed with the Logix Designer application is extremely useful
for answering specific questions that arise while creating a controller project. So, let’s take a
look in the Logix Designer help to get an idea of the elementary data types available for our use.
2
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Level 1: Logix - On Demand
Exploring Elementary Data Types
3.
In the top ribbon menu of your Logix Designer project, expand Help and select
Contents:
4.
In the Search box of the browser that appears, type ‘Elementary Data Types’ and press
Enter on your keyboard:
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Exploring Elementary Data Types
Level 1: Logix - On Demand
5.
Scroll down the list of Search Results and select Elementary data types:
6.
Read through the resulting table of elementary data types to get an idea of available
data types and their characteristics.
Generally speaking, the original elementary data types found within the Logix Designer
application were BOOL, SINT, INT, DINT and REAL. The three integer types were signed, using
two’s complement representation. The 64 bit LINT was also available, but its use was somewhat
limited. With the introduction of version 32, the 64 bit and unsigned integer data types became
available for use in high-performance controllers (e.g., 1756-L8z, 5069-L3z).
7.
4
Close the Help browser.
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Level 1: Logix - On Demand
Exploring Elementary Data Types
8.
Within the Controller Organizer of your Logix Designer project, locate and double click
the Controller Tags:
9.
Select the Edit Tags tab:
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Exploring Elementary Data Types
Level 1: Logix - On Demand
10.
Add the following tags to the table:
11.
Select the Monitor Tags tab:
12.
In the Value column for the BOOL tag, type ‘2’ and press Enter on your keyboard:
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Level 1: Logix - On Demand
13.
Exploring Elementary Data Types
Read the warning that appears and click the OK button:
This is an example of what occurs when we attempt to write a value to a tag of a data
type too small for the particular value.
14.
Type ‘1’ for the BOOL Value and press Enter on your keyboard:
15.
In the Value column for the SINT tag, type ‘5.5’ and press Enter on your keyboard:
16.
Read the warning that appears and click the OK button:
This is an example of what occurs when we attempt to write a decimal value to an
integer tag.
17.
Type ‘-100’ for the SINT Value and press Enter on your keyboard:
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Exploring Elementary Data Types
Level 1: Logix - On Demand
18.
Click the arrow next to the SINT tag to reveal its individual bits:
19.
In the Value column for SINT.7, type ‘0’ and press Enter on your keyboard:
The individual bits of an integer data type can be (and frequently are) used individually,
rather than using the overall integer value. For example, instead of using an individual
Boolean tag, we could assign SINT.7 to a bit-level instruction. In such cases, it is
generally preferable to view the overall integer value in binary format, rather than
decimal.
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Level 1: Logix - On Demand
20.
Exploring Elementary Data Types
In the Style column for the SINT tag, select Binary:
Now we can see the individual bit values at a glance, without having to expand the
integer. Furthermore, this allows us to see the bit values if we happen to use the overall
integer value in an instruction such as a compare instruction.
21.
Click the arrow next to SINT to once again collapse the tag:
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Exploring Elementary Data Types
Level 1: Logix - On Demand
22.
In the Value column for the USINT tag, type ‘-100’ and press Enter on your keyboard:
23.
Read the warning that appears and click the OK button:
This is an example of what occurs when we attempt to write a negative value to an
unsigned integer tag.
24.
Type ‘100’ for the USINT Value and press Enter on your keyboard:
25.
In the Value column for the REAL tag, type ‘5.5’ and press Enter on your keyboard:
The REAL and LREAL data types provide the necessary ability to work with decimal
values.
26.
Continue testing the functionality of the elementary data types until you are satisfied with
your understanding of their capabilities and limitations.
Now that we have seen how these data types function, we can delete the tags, as they
serve here only as examples. However, to delete tags, the table must be on the Edit
Tags tab.
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Level 1: Logix - On Demand
27.
Select the Edit Tags tab:
28.
Click the square to the left of the BOOL tag:
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Exploring Elementary Data Types
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Exploring Elementary Data Types
Level 1: Logix - On Demand
29.
While holding down the Shift key on your keyboard, click the square to the left of the
LREAL tag:
30.
Press the Delete key on your keyboard:
31.
Close the Controller Tags.
In these examples, we were working with controller tags. However, the same principles apply to
local tags and program parameters as well.
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