Electromechanical Engineering Technology
Unit A exercises
RSLogix 500 Tutorial 1: This tutorial guides you to the creation of a ladder logic diagram in RSLogix 500 that controls pilot lights. The ladder diagram to be created is shown as follows:
Input/Output list Component
Input/Output Number
PB1 (PUSH_BUTTON)
I0:0/1
PB2 (PUSH_BUTTON)
I0:0/2
PL0 (PILOT_ LIGHT 1)
O0:0/0
ELMT-1301 Basic Programmable Logic Controllers
pg.1 of 10
Electromechanical Engineering Technology
Unit A exercises
Creating a new file 1.
On your Start menu, select
2. 3.
Click New on the icon bar, or click File, New. The Select Processor Type dialog box appears. On the dialog box, scroll through the processor list and select: "Bul. 1762 MicroLogix 1200 Series A" and click OK. The RSLogix window appears as shown in Figure 1. (The screen does not have to be an exact match)
Figure 1. RSLogix 500 window.
ELMT-1301 Basic Programmable Logic Controllers
pg.2 of 10
Electromechanical Engineering Technology
Unit A exercises
The RSLogix window contains the following: Menu bar. Select functionality from the menus that appear as you click each selection on this bar. Icon bar. It contains several functions that you will use repeatedly as you develop and test your logic program. In order to know what each of the icons do, simply move your cursor to the icon and a floating ToolTip window will appear indicating the icon’s function. Online bar. It indicates the operational mode and lets you see whether you have online edits or forces installed at a glance. Project tree. It contains all the folders and files contained in your project. Most of the icons in the tree offer a menu applying only to itself by selecting the icon and clicking the right mouse button. The menu contains options to execute an action on the folder or file. Status bar. It provides you with ongoing status information or prompts as you use the software. Results pane. It displays the results of a Find All search or a verification procedure. Ladder view. This is where you edit your ladder logic. You can also view several program files at the same time. Instruction toolbar. It displays instruction mnemonics in tabbed categories. Each time you select a category tab, the instruction toolbar provides you with instructions for that category. You can click on any instruction to insert it in your ladder program.
Creating the first rung 1.
The new program file contains only an End rung. Click the rung number of the End rung (0000) to select it and then select the New Rung icon from the instruction toolbar (Figure 2). You can also insert a new rung by selecting the End rung number and clicking the right mouse button, then, select Insert Rung from the menu that appears. A new rung appears above the End rung.
Figure 2. Instruction toolbar. NOTE: Rungs under edit have the lower-case letter e in the margin to the left of the left rail. This means that these rungs have not yet been verified and compiled. The letter e should disappear once the file is compiled and no errors have been detected. 2.
To insert an instruction on a rung, click its icon on one of the toolbars. At this point, click on the Examine if Closed icon . A normally open contact appears on the rung. NOTE: You can place several instructions on a rung sequentially by clicking the icons one after another. The instructions are placed from left to right. You can also place instructions by dragging and dropping the icons until a green rectangle appears in the desired location.
ELMT-1301 Basic Programmable Logic Controllers
pg.3 of 10
Electromechanical Engineering Technology
Unit A exercises
The following list describes some of the instructions from the User toolbar shown in Figure 2: Instruction Icon
Name
Description
Functions as an input or storage bit. If it is ON, it will allow rung XIC - Examine continuity and outputs if Closed will be energized. Functions as an input or storage bit. If it is ON, it will not allow XIO - Examine rung continuity and if Open outputs on the rung will be de-energized. OTE - Output Energize
Sets the specified bit when rung continuity is achieved (rung goes true).
OTL - Output Latch
Functions about the same as OTE except that once a bit is set with an OTL, it is "latched" on. The bit must be reset with an OTU instruction.
OTU - Output Unlatch
It unlatches a latched bit which was set by an OTL instruction. The address for this instruction should be identical to the OTL address that originally set the bit.
Next, we will assign an address to the instruction so that RSLogix can identify it. Addresses are made up of alphanumeric characters separated by delimiters. Delimiters include the colon, period, and slash. An address is usually in the form X:Y/Z , where X is the data file type, Y is the number of the control box that the instruction is connected, (for this tutorial, there is only one controller so the variable will always be 0), and Z can be a number or a word identifying the number of the external I/O or other instructions used. Data files contain the status information associated with external I/O and all other instructions you use in your ladder program files. Moreover, these files store information about controller operation. The following table shows the default file types: File #
File Description
File Type O0
Stores the state of output terminals for the controller.
Output I1
Stores the state of input terminals for the controller.
Input S2
Stores controller operation information useful for troubleshooting controller and program operation.
Status B3
Stores internal relay logic.
ELMT-1301 Basic Programmable Logic Controllers
pg.4 of 10
Electromechanical Engineering Technology
Unit A exercises
Bit T4
Stores the timer accumulator and preset values and status bits.
Timer C5
Stores the counter accumulator and preset values and status bits.
Counter R6
Stores the length, pointer position, and status bits for specific instructions such as shift registers and sequencers.
Control N7
Used to store numeric values or bit information.
Integer
3.
The instruction just placed is an input. To assign the data file type to it, double-click on the normally open contact placed and enter "I1:0/1". Next, we will assign a symbol to the instruction that can be used as a substitute for an address so that the instruction can be easily identified. All instructions having the same address automatically have the same symbol. A symbol is unique. The same symbol cannot be applied to different addresses. Symbols can be up to 20 characters in length.
4.
To assign a symbol to the instruction, right-click the normally open contact added to the rung. A menu prompts and then select Edit Symbol. Enter "PB1" and then hit the Enter key on the keyboard. NOTE: Anytime you right-click any element in the ladder diagram, a menu prompts with editing options for the selected element.
5.
Click the first rung number (0000) and then click the Rung Branch icon appears.
. A new branch
NOTE: When placing a branch, if your cursor is on an instruction, the branch is placed immediately to the right of the instruction. If your cursor is on the rung number, the branch is placed first on the rung. For more information about branching, please refer to the section "Branching". 6.
Click the right leg of the branch and drag the leg to the right of the "PB1" contact. A valid release point will be shown as a green rectangle on the ladder display.
ELMT-1301 Basic Programmable Logic Controllers
pg.5 of 10
Electromechanical Engineering Technology
Unit A exercises
7.
Click on the lower left leg of the branch and then click the Examine if Closed icon click this contact and enter the address "I1:0/2".
. Double-
8.
To assign a symbol to the instruction, right-click the normally open contact added to the rung. A menu prompts and then select Edit Symbol. Enter "PB2" and then hit the Enter key on the keyboard.
9.
Click the right leg of the branch and then click on theOutput Energize icon appears. Double-click the output and enter the address "O0:0/0".
. An output load
10. To assign a symbol to the instruction, right-click the normally open contact added to the rung. A menu prompts and then select Edit Symbol. Enter "PL0" and then hit the Enter key on the keyboard. 11. Your ladder diagram should look as follows:
Verifying the file 1.
Click the Verify File icon or click Edit, Verify File from the menu bar. If your file has any mistakes, the Verify Results output window displays and gives you information about mistakes or omissions occurred in your program. If your program does not have any mistakes, then the lower left corner of the RSLogix window states: "Verify has completed, no errors found".
Saving the file 1. 2.
Click the File, Save, type tutor 1 under File Name: Click on Save.
Testing the file 1.
There is an OFFLINE list box on the upper left corner of the RSLogix window. Click on the arrow on the right and select Download…(See Figure below).
ELMT-1301 Basic Programmable Logic Controllers
pg.6 of 10
Electromechanical Engineering Technology
Unit A exercises
2.
Click OK. The following dialog box appears:
3. 4.
Click Yes. The following dialog box appears:
5.
Click Yes. RSLogix will download your program so it can be tested on the testing board located on your left. The following two dialog boxes appear:
ELMT-1301 Basic Programmable Logic Controllers
pg.7 of 10
Electromechanical Engineering Technology
6.
Unit A exercises
Click Yes on both dialog boxes. Now, your program is on the REMOTE RUN mode as shown on the upper left corner of the RSLogix window. NOTE: Your program has to be on the REMOTE RUN mode in order to be tested on the testing board.
7.
Test your program by pressing PB1 and PB2 and observe what happens to PL0 on your plc trainer.
8.
When you are done testing, click on the arrow on the right of REMOTE RUN (as shown in the figure below) and select Go Offline. If your program works fine, close your program. Otherwise, make the necessary modifications to your program and test it again.
NOTE: You have to be on the OFFLINE mode in order to make any modifications to your program. Printing the file 1. 2.
Click File, Print View. On the Print window, click OK.
ELMT-1301 Basic Programmable Logic Controllers
pg.8 of 10
Electromechanical Engineering Technology
Unit A exercises
Practice 1.
Add the logic as shown in the ladder diagram below:
Questions 1.
When does PL0 turn ON?
2.
Why is PL3 ON if PB5 is not ON?
3.
When does PL2 turn ON?
4.
Why do PL1 and PL2 turn on simultaneously?
5.
How do you turn OFF PL3?
ELMT-1301 Basic Programmable Logic Controllers
pg.9 of 10
Electromechanical Engineering Technology
Unit A exercises
Branching The following are instructions for dealing with branches:
Adding a branch. Click the Rung Branch icon on the instruction toolbar to place a branch in your ladder logic. If the cursor is on an instruction, the branch is placed immediately to the right of the instruction. If the cursor is on the rung number, the branch is places first on the rung. Moving a branch. Click on the upper left corner of a branch another location in your ladder logic program.
to move the entire branch structure to
Expand a branch. Click the right leg of the branch , then drag the leg to the right or left. All valid release points are shown in green color on the ladder display. Nested branches. Click the upper left corner of a branch leg , then click the right mouse button, and select Append New Branch to place another branch structure within the original branch structure.
Parallel branches. Click the bottom left corner of a branch leg and select Extend Branch Leg Up or Extend Branch Leg Down.
, then click the right mouse button,
Copying a branch leg. Click on the left edge of the branch leg you want to copy . Then click the right mouse button and select Copy. Next, click on a rung or instruction in your logic and click Paste from the right mouse menu to insert the rung leg. Copying the entire branch structure. Click the right leg of the branch structure , then click Copy from the right mouse menu. Next, click on a rung or instruction in your logic and click Paste from the right mouse menu to insert the rung structure. Deleting a branch. Simply click at any location on the branch and select Delete from the right mouse menu.
ELMT-1301 Basic Programmable Logic Controllers 10
pg.10 of
