Exercise C
6--13 6--13 Exercise: Creating Tags and Monitoring Data in an RSLogix 5000 Project
E 2007 Rockwell Automation, Inc. All rights reserved.2007 Rockwell Automation, Inc. All rights reserved.
Rev. February 2007 Rev. February 2007
TAGe56r 11.
11. What happens to the Conveyor_Sta rt_Time timer data?
12.
12. On your workstation , press Conveyor_S top (button DI1).
13.
13. What is the value of the C onveyor_Moving tag?
14.
14. Close the project.
Turn to the Answers section.
How Did You Do?
How Did You Do?
6--14
6--14 Exercise: Creating Tags and Monitoring Data in an RSLogix 5000 Project
E 2007 Rockwell Automation, Inc. All rights reserved.2007 Rockwell Automation, Inc. All rights reserved. Rev. Rev. February February 20072007 TAGe56r
Exercise A Exercise A
1.
1. The common memory size s are labelled in the following table:
D
Deessccrriippttiioon n UUnniit t oof f MMeemmoorryy A unit of memory in a controller composed of 16
A unit of memory in a controller composed of 16 individual bits or two bytes that are treated as
individual bits or two bytes that are treated as one unit.one unit. WordWord The smallest unit of data represented by the
The smallest unit of data represented by the digits 0 and 1.
digits 0 and 1. BitBit
A string of 8 bits operated on as one unit.
A string of 8 bits operated on as one unit. ByteByte
2.
2. A tag is an area of controller mem ory where data from devices , calculations, faults, etc. is stored. Each area is given a unique name.
3.
3. A data type is the definition of how many bits, bytes , or words of data a tag will use.
4.
4. The data type is based on the source of the inform ation.
5.
5. The programmer would select a TIMER data type.
6.
6. Based on the type of data (REAL), the AirT emperature tag is connected to an analog device. systems. It is the main data type because it is the minimum memory allocation for any tag.
9.
9. An alias tag is an additional nam e for a tag (or another alias tag). An alias tag can be used to identify an automatically generated I/O tag with a complex name. For example, Motor can be an alias tag for Local:2:O.D ata.15.
10.
10. A tag that can be access ed by every program and routine is a controller-scoped tag.
11.
11. To modify tag values in an active controller (online) you must select the Monitor tab.
12.
12. To create and delete tags yo u must select the Edit tab.
13.
13. All of the statemen ts regarding the disp lay of tags in a tags collection are true:
n Tags of the same data type are not automatically displayed together.
n Tags can be displayed alphabetically (default mode).
n Tags can be sorted and filtered (e.g., show DINT tags only).
n Tags that are structures (TIMER, etc.) can be expanded to display members.
Answers
Answers
6--15 6--15 Exercise: Creating Tags and Monitoring Data in an RSLogix 5000 Project
E 2007 Rockwell Automation, Inc. All rights reserved.2007 Rockwell Automation, Inc. All rights reserved.
Rev. February 2007 Rev. February 2007
TAGe56r
Exercise B Exercise B 2.
2. Your tag database should appear similar to the following example:
Controller Scope
Controller Scope FilterFilter
Sort By Name Sort By Name
Exercise C Exercise C
2.
2. The following alia s tags tags were created:
9.
9. The Conveyor_Moving light (DO5) alternat es with the Process light (DO2).
10.
10. The values of Conveyor_M oving and Process altern ate between on (1) and off (0).
11.
11. The Conveyor_Start_Timer timer tag begins collecting timer data each time Conveyor_Moving is on (1).
13.
13. Conveyor_Stop stops the conveyor . Therefore, the value of Conveyor_Moving is also 0.
6--16
6--16 Exercise: Creating Tags and Monitoring Data in an RSLogix 5000 Project
E 2007 Rockwell Automation, Inc. All rights reserved.2007 Rockwell Automation, Inc. All rights reserved. Rev. Rev. February February 20072007 TAGe56r
Lesson Lesson 7 7
E 2007 Rockwell Automation, Inc. All rights reserved.2007 Rockwell Automation, Inc. All rights reserved.
Rev. February 2007
After completing this lesson, you should be able to troubleshoot an RSLogix 5000 project by performing the following tasks:
• Monitor array tags through the Tags window
• Monitor tags of user- defined data types through the T ags window
Why These Skills Are Important Why These Skills Are Important
Often, well-des igned applications take advantage of more complex tags. These tags may combine multiple elements of the same data type into an array or may consist of new, user-defined data types.
Understanding how to interpret and monitor these complex tags is essential to troubleshooting an application.
Key Terms Key Terms Array
Array: A numerically indexed sequence of elements of the same data type. An array tag occupies a contiguous section of memory in the controller with each element in sequence. Arrays can have one, two, or three dimensions .
Element
Element: A single position within an array.
Example: Array Example: Array
A controller needs to store a piece of data for six different parts.
This data can be stored in an array of 6 INTs:
Array of 6
Review the definition of the term tag.
Review the definition of the term tag.
Before You Begin Before You Begin
Note that an array that is a member of Note that an array that is a member of user-defined data type can only have user-defined data type can only have one dimension.
one dimension.
Relate this to PLC-5 data, where N7:0 to Relate this to PLC-5 data, where N7:0 to N7:9 is a one-dimensional array of N7:9 is a one-dimensional array of integer data types.
integer data types.
Note that an array of Part[40] will have Note that an array of Part[40] will have elements of Part[0] to Part[39].
elements of Part[0] to Part[39].
Stress that it is easier for a programmer Stress that it is easier for a programmer to create a
to create a single-dimensionsingle-dimensional array ofal array of 100 DINTS than it is to create 100 100 DINTS than it is to create 100 individual tags.
individual tags.
Point out that you can create an alias Point out that you can create an alias tag for each element of an array. For tag for each element of an array. For example, Cold_Timer might be an alias example, Cold_Timer might be an alias for TIMER [34].
for TIMER [34].