Instant PLC Programming with RSLogix 5000

First, we will need to open RSLogix 5000 from the drop-down menu and then navigate to File | New or press Ctrl + N.

The New Project window will appear and allow us to give a name to our new project and configure it for a particular controller and firmware revision. In this book, we will be using the 1756-L75 with firmware Version 19. Feel free to use whichever hardware is available or the RSLogix Emulate 5000 Controller if a PLC is not available; but, keep in mind that the hardware may impact your ability to complete all the exercises in this book.

Set the remaining fields to the following values:

Click on the Browse button to choose a location on your computer on which to save your project.

At the bottom of the Controller Organizer window, expand the I/O Configuration folder, right-click on the Backplane node, and select New Module... from the menu as shown in the following screenshot:

Next, we will select the module that will be added to our rack. We will be adding a basic 8 channel analog input card. Expand the Allen Bradley Analog category and choose 1756-IF8.

Now, we are presented with the New Module window where you can specify the name and description of the module. We will identify this module based on its rack and slot position—RACK01_SLOT01 as shown in the following screenshot:

After adding the new module, the Module Properties window is displayed (or can be opened by double-clicking on the module). The Module Properties window will allow us to configure the channel, calibrate the card, and modify the Requested Packet Interval (RPI) and alarm information of our analog input module.

We will configure our analog input module's first channel (Channel 0) to be a typical 4 ma to 20 ma input by navigating to the Configuration tab and selecting an input range of 0 ma to 20 ma from the dropdown.

Now, we will set the information in the Scaling group box to the following values:

This process must be repeated for all the four channels. We can select and configure the three remaining channels by clicking on the small square buttons labeled 1, 2, 3, and following the same method.

Finally, we will click on the OK button to save our module configuration.

First, we will create a tag using the New Tag window. You can open the new tag window by right-clicking on the Controller Tags folder of the Controller Organizer (to display the Controller Organizer, press Alt + 0) and selecting New Tag (or by pressing Ctrl + W).

The New Tag window allows us to configure several parameters for our tag. The first tag we will create will be a base tag that will be used internally in the program and is not directly associated to a card in the controller. The first base tag will be the set point for the flow control valve FC1001, so we will give it a text-based named association of FC1001_SP.

Along with the name, setting a description is a recommended best practice. We will set the description to FLOW CONTROL 1001 SET POINT. Refer to the upcoming screenshot.

Next, we will set the Type dropdown to Base.

We will set the Data Type of our base tag to REAL.

We will set the value of Scope to FirstController.

Setting the scope to Controller level will allow us to use this tag in all the tasks and programs in the project (Global scope).

The External Access field is set to Read/Write so that our operator will be able to set the value from the HMI.

The Style dropdown allows us to modify the way the value is displayed and the choices vary depending on the data type that is being used. The following screenshot shows all of these settings:

Finally, we will click on OK to finish adding our variable tag to the project.

Now, we will double-click on the Controller Tags leaf of the Controller Organizer and view our newly added tag in the Controller Scope pane of our project.

Next, we will repeat the same process for an Alias tag that will be directly associated with the analog output of the flow control valve. This time, we will use the Controller Tags pane to enter our new tag into the Tags table. At the bottom of the Controller Tags pane, there is a tab labeled Edit Tags and, if we click on that tab, we can type a tag into the bottom row of the table as if we were adding it to a spreadsheet.

In the Name column, set the value to FC1001_PV.

In the Alias for column, select the data outputted from the analog input card. We added Local:1:I.Ch0Data as shown in the following screenshot:

Finally, set the description to FLOW CONTROL VALVE 1001 PROCESS VALUE.

Open Controller Organizer and expand the leaf Tasks | Main Tasks | Main Program. Right-click on Main Program and select New Routine as shown in the following screenshot:

Configure a new Ladder Logic program by setting the following values:

For our newly created routine to be executed with each scan of the PLC, we will need to add a reference to it in MainRoutine that is executed with each scan of the MainTask task.

Double-click on our MainRoutine program to display the Ladder Logic contained within it.

Next, we will add a Jump To Subroutine (JSR) element that will add our newly added Ladder Diagram program to the main task and ensure that it is executed with each scan.

Above the Ladder Diagram, there are tab buttons that organize Ladder Elements into Element Groups. Click on the left and right arrows that are on the left side of Element Groups and find the one labeled Program Control. After clicking on the Program Control element group, you will see the JSR element. Click on the JSR element to add it to the current Ladder Logic Rung in MainRoutine.

Next, we will make some modifications to the JSR routine so that it calls our newly added Ladder Diagram. Click on the Routine Name parameter of the JSR element and select the VALVES routine from the list as shown in the following screenshot:

There are three additional parameters that we are not using as part of the JSR element, which can be removed. Select the Input Par parameter and then click on the Remove Parameter icon in the toolbar above the Ladder Diagram. This icon looks as shown in the following screenshot:

Repeat this process for the other optional parameter: Return Par.

Now that we have ensured that our newly added Ladder Logic routine will be scanned, we can add the elements to our Ladder Logic routine. Double-click on our VALVES routine in the Controller Organizer tab under the MainTask task.

Find the Timer/Counter element group and click on the TON (Timer On Delay) element to add it to our Ladder Diagram.

Now we will create the Timer object. Enter the name in the Timer field as FC1001_TON. Right-click on the TIMER object tag name we just entered and select New "FC1001_TON" (or press Ctrl + W).

In the New Tag form that appears, enter in the description FAULT TIMER FOR FLOW CONTROL VALVE 1001 and click on OK to create the new TIMER tag.

Next, we will configure our TON element to count to five seconds (5,000 milliseconds). Double-click on the Preset parameter and enter in the value 5000, which is in milliseconds.

Now, we will need to add the condition that will start the TIMER object. We will be adding a Less Than (LES) element from the Compare element group. Be sure to add the element to the same Ladder Logic Rung as the Timer on Delay element.

The LES element will compare the valve position with the valve set point and return true if the values do not match. So set the two parameters of the LES element to the following:

Now, we will add a second Ladder Logic Rung where a latched fault alarm is triggered after TIMER reaches five seconds.

Right-click under the first Ladder Logic Rung and select Add Rung (or press Ctrl + R).

Find the Favorites element group and select the Examine On icon as shown in the following screenshot:

Click on ? above the Examine On tab and select the TIMER object's Done property, FC1001_TON.DN, as shown in the following screenshot. Now, once the valve values are not equal, and the TIMER has completed its count to five seconds, this Ladder Logic Rung will be activated as shown in the following screenshot:

Next, we will add an Output Latched element to this Ladder Logic Rung. Click on the Output Latched element from the Favorites element group with our new rung selected.

Click on ? above the Output Latched element and type in the name of a new base tag we are going to add as FC1001_FLT. Press Enter or click on the element to complete the text entry.

Right-click on FC1001_FLT and select New "FC1001_FLT" (or press Ctrl + W).

Set the following values in the New Tag form that appears:

Click on OK to add the new tag. Our new tag will look like the following screenshot:

It is considered bad practice to latch a bit without having the code to unlatch the bit directly below it. Create a new BOOL type tag called ALARM_RESET with the following properties:

Click on OK to add the new tag. Then add the following coil and OTU to unlatch the fault when the master alarm reset is triggered.

Finally, we will add a comment so that we can see what our Ladder Diagram is doing at a glance.

Right-click in the far-right area of the first Ladder Logic Rung (where the 0 is) and select Edit Rung Comment (Ctrl + D).

Enter the following helpful comment:

TRIGGER FAULT IF THE SETPOINT OF THE FLOW CONTROL VALVE 1001 IS NOT EQUAL TO THE VALVE POSITION

Open Controller Organizer in RSLogix 5000 and find the Controller Module (or modules for your project). Right-click on the Controller module and select Properties (or press Alt + Enter).

In the Controller Properties window, navigate to the Major Faults tab and check for any faults that may have occurred.

Now, click on the Minor Faults tab and check for any faults that may have occurred.

You can also check to see if there are any errors with the PLC program itself by navigating to Logic | Verify | Controller.

If any errors occur, they will be listed in the Errors Pane that is displayed.

Before we can communicate with our PLC, we will need to set up the communications path in a separate program called RSLinx that is installed with RSLogix 5000. Open RSLinx and then, from the drop-down menu, navigate to Communications | Configure Drivers as shown in the following screenshot:

The Configure Drivers window allows you to add Driver to the Configured Drivers list. In the Available Driver Types group box, use the dropdown and select the EtherNet/IP Driver option, and then click on the Add New… button.

Next, a window will appear asking you to specify the name of Driver; use the default driver name and click on OK.

A Configure Driver window will appear next; simply click on OK to accept the default settings.

We have completed our communications driver configuration in RSLinx, so we can close that application for now and switch back to RSLogix 5000.

In order to download our program to the controller, we first need to specify the communications path. You can see the currently selected communications Path on Communications Toolbar:

Click on the Who Active icon to the right-hand side of Communications Toolbar and specify the communications path. This icon looks like the following screenshot:

The Who Active window will appear and allow you to specify the path to your PLC. Expand the AB_ETHIP driver we added using RSLinx, select your PLC, and then click on the Download button.

A version mismatch message may appear; just click on OK to accept and overwrite the current PLC program.

Now that we have downloaded the PLC program to the PLC, if you check the PLC status pane in the top-left corner of Logix 5000, you will see that you are now online.

Click on the Who Active icon as shown in the following screenshot:

The Who Active window will appear. Use the network browser tree to select your PLC on the network.

Now we are ready to upload the PLC program to our computer. Click on the Upload button.

The Connected To Upload window provides more details about the current PLC and the program state. Hit the Upload button to start the upload process.

If you have made any changes to the project that you currently have open, you will see a Save Changes dialog. Click on No.

An uploading progress bar will be displayed when the upload process begins.

Once the upload process is complete, you will see that you are now online on the PLC.

When you are online on your PLC (if you are not sure how to do this read the recipes Uploading explained (Simple) and Downloading explained (Simple)), right-click on Program Tags, and select New Tag… (or press Ctrl + W).

On the New Tag form that appears, create a new base type tag using the following values:

Now, we are going to add our newly created POWER_FAILURE tag to the VALVES Ladder Logic Routine. Open the VALVES routine by double-clicking on it from the Controller Organizer tree.

Now, the tricky part with an online change in RSLogix 5000 is that we cannot make modifications to an existing Ladder Logic that is currently running. However, we can add new Ladder Logic Rungs. So the workaround for editing rung is to copy and paste an existing rung, modify it, and then delete the old rung. So, let's copy the existing rung at position one by right-clicking on it and selecting Copy (or press Ctrl + C).

Next, we will paste our rung under the existing rung by right-clicking on it and selecting Paste (or press Ctrl + V).

After pasting the rung, you will notice that iiiii will appear to the left of the rung indicating that it is pending insertion.

Now that we have added the new rung, we can edit and go ahead and delete the old rung. Right-click on the only rung and click on Delete (or press Delete).

After deleting the old rung, you will notice that ddddd appears to the left of the rung indicating that it is pending deletion.

Now we can make our modification to our newly inserted rung. Choose the rung we have inserted and click on the Examine Off element to add it.

Click on ? above the Examine Off element and associate it with the POWER_FAILURE tag. The following screenshot displays the Examine Off element with the associated tag.

The changes we have made to the routine will not execute until we finalize our program (or accept, test, and assemble it). From the drop-down menu, navigate to Logic | Online Edits | Finalize All Edits in Program (or press Ctrl + Shift + F).

A dialog box will appear confirming that you want to finalize all edits to the program. Click on Yes.

After finalizing the edits, you will notice that the iiiii and ddddd indicators have disappeared and the new logic is now live.

Open the Controller Organizer window and expand the tree Tasks | Main Tasks | Main Program. Right-click and select New Routine.

Configure a new FBD routine by setting the following values:

In order that our newly created routine executes with each scan of the PLC, we will need to add a reference to it in MainRoutine, which is executed with each scan of the MainTask. Repeat Steps 3 to 7 of the Building Ladder Diagram programs recipe (or copy and paste the existing JSR), but use the Routine name DIGITAL_ALARMS in the JSR element.

Now we will return to our DIGITAL_ALARMS FBD by double-clicking on it in the Controller Organizer window.

Next, we are going to add our Digital Alarm FBD, which we will use to manage our valve alarm fault. Select the Alarms element group in the FBD toolbox just above the FBD and click on the ALMD (Alarm Digital). The following screenshot displays the Alarms element group.

We need to connect the ALMD block to our valve fault alarm using an Input Reference, so let's add one to our FBD. The Input Reference object looks like an arrow (with a square corner) that is pointing to the right, as shown in the following screenshot. It can be found at the top-left area of the Element Group selector above the FBD. Click on the Input Reference object icon to add it to the diagram. This icon looks as shown in the following screenshot:

We will now set the input reference to point to our fault Base Tag. Click on the Input Reference icon, click on the drop-down option, and select FC1001_FLT.

Now we will need to reposition our blocks so that they fit properly on our FBD sheet. Click-and-drag the ALMD object to the right by a few inches.

Now we will connect the FC1001_FLT Input Reference to the ALMD block. Click and drag the point of the Input Reference object (you will see the mouse pointer change to a connector mouse icon) and release the mouse button over the Input Digital Pin object.

The ALMD function block that we added was automatically created as a base type object in our program scope tag list (Program Tags). We will now change the name of the ALMD object to follow our existing tag naming convention. Right-click on the top title of the ALMD object and navigate to the Edit | ALMD_01 element.

Select the Name field in the element property and change it to: FC1001_FLT_ALM and click on OK. The scope of our FBD Base tag is set to MainProgram automatically when we added it to our routine. The routine now looks like the following screenshot:

First, we will need to declare our new routine. Right-click on MainProgram of the Controller Organizer and select New Routine.

In the New Routine form that appears, enter or select the following:

Then click on OK.

In order for our newly created routine to be executed with each scan of the PLC, we will need to add a reference to it in MainRoutine that is executed with each Scan of the MainTask. Repeat Steps 3 to 7 of the Building Ladder Diagram programs recipe (or copy and paste the existing JSR), but use the routine name CALCULATIONS in the JSR element.

We will use a simple linear equation to calculate the Flow value based on our Valve position. Enter in the following structured text comment and simple formula code as shown in the following screenshot:

//Linear flow calculation based on valve position FC1001_FLOW := FC1001_PV*0.83823;

The tag FC1001_FLOW must be added to our controller, so right-click on the FC1001_FLOW tag in our structured text and select New Tag "FC1001_FLOW".

On the New Tag form, enter the following values:

Then click on OK.

First, we will need to declare our new routine. Right-click on MainProgram of Controller Organizer and select New Routine.

In the New Routine form that appears, enter or select the following:

Then click on OK.

In order for our newly created routine to be executed with each scan of the PLC, we will need to add a reference to it in MainRoutine that is executed with each Scan of MainTask. Repeat Steps 3 to 7 of the Building Ladder Diagram programs recipe (or copy and paste the existing JSR), but use the routine name BACKWASH in the JSR element.

Now we will add an Action to Step_000 that was created by default. Right-click on Step_000 and select Add Action.

Now we will add the initialization values for our SFC using ST syntax. Double-click on the box with ? at the bottom of Action_000 and enter the following structured text as shown in the following screenshot:

BACKWASH_START_PB:=0;
BACKWASH_FLT:=0;

An icon with a red cross will appear to the side of Action_000, indicating that there is an error with the ST we have added. The error is due to the fact that BACKWASH_START and BACKWASH_FLT do not yet exist in our program.

We can easily add these values by right-clicking on the BACKWASH_START_PB tag in the Action_000 box and selecting the New Tag "BACKWASH_START_PB" option.

The New Tag form will appear, which will allow us to create our new tag as follows:

Repeat the same process for the second new tag by right-clicking on the tag BACKWASH_FLT and the New Tag form and entering the following values:

Next, we will add the Transition conditional value that will start our Backwash sequence. Double-click on the Tran_000 question mark and enter the following logical statement (which is equivalent to BACKWASH_START_PB=1) BACKWASH_START_PB.

Now we can add our backwash sequence step. Select the Transition box Tran_000 and then click on the Step element icon in the SFC element group above our SFC program. The step box, Step_001, will be added and automatically connected to Tran_000 (because we selected it before adding our new step).

Next, we can add an action to Step_001 that will represent our backwash process. Right-click on Step_001 and select Add Action.

Now we will add our action ST to the action element by double-clicking on ? in Action_001 and entering FC1001_SP:=100;.

Let's add a delay to Step_001 in order to give our backwash time to complete. Right-click on Step_001 and select the Step Properties menu option. On the Step Properties form, set the Preset field to 30000 ms (30 seconds). Click on OK.

Next, we will add a Selection Branch Diverge in order to reset our sequence or trigger a fault if there is a problem. Select Step_001 and then click on the Selection Branch Diverge Element icon just above our sequence chart. The icon is shown in the following screenshot:

A Selection Branch Diverge can also allow you to execute one or another sequence, while Simultaneous Branch Diverge will execute two sequences in parallel. Our sequence will automatically reset and await another backwash if the valve has successfully opened, 100 percent. Select Tran_001 and click on the ? icon to set the logical statement that will execute this Selection Branch. Type in the following structured text logical statement: FC1001_PV=100.

We want our sequence to reset after it has completed the backwash, so we will connect a flow line from our transition Tran_001 to the top element in our sequence, Step_001. Click on the connector box under Trans_001 and drag it to the connector box on top of Step_000.

If our valve fails to open, we want to raise a fault before resetting our sequence. Select Tran_002, click on ?, and enter the following structured text logical statement; FC1001_PV<>100.

In order to raise a fault, we will need to add a Step. Select Tran_002 and click on the Step Element icon.

Add an action to our newly created step, Step_002, by right-clicking and selecting Add Action.

Double-click on ? of our newly added action and add the following ST code:

BACKWASH_FLT:=1;
BACKWASH_START_PB:=0;

In order to make our sequence easy to understand, let's add a Text Box comment. Click on the Text Box element to add it to the sequence diagram and drag it to the right of the sequence. Enter in the following comment: Backwash fault triggered if valve FC1001 fails to open.

In Controller Organizer, right-click on the Tasks icon and click on New Task.

In our project, there is no need to check for our non-critical alarms every 10 ms. We will create a new periodic task for processing alarms every 250 ms and give it low priority in order to reduce the load on our processor.

In the New Task form that appears, enter the following values:

Next, we will add our Program that will contain our Alarm function and handle the alarm processing for our project.

Right-click on our newly created AlarmTask task and click on the New Program option.

In the New Program form that appears, enter the following values:

Now we can move the DIGITAL_ALARM routine, which we created earlier in the book, to our newly created Alarm program. Expand MainTask and MainProgram in the Controller Organizer Tasks and drag-and-drop the DIGITAL_ALARM routine from MainProgram to MainAlarmProgram as shown in the following screenshot:

As we learned earlier, in order for a routine to be executed, it must be linked to a program. We will now set the DIGITAL_ALARM routine as the MainRoutine of MainAlarmProgram. Right-click on MainAlarmProgram and select Properties (or hit Alt + Enter). In the Program Properties form that appears, select the Configuration tab and, under the Assign Routines header, select DIGITAL_ALARM from the Main dropdown as shown in the following screenshot:

You will notice that, after assigning the DIGITAL_ALARM routine as the MainRoutine for MainAlarmProgram as shown in the following screenshot, the DIGITAL_ALARM icon changes to display 1 that indicates that it is the MainRoutine for the program:

Next, we will check to see whether or not we have introduced any errors in our controller with our latest changes. From the drop-down menu at the top of RSLogix 5000, navigate to Logic | Verify | Controller.

You will notice that the Errors pane has appeared and the following errors are listed:

Clicking on the first error message will directly take you to the DIGITAL_ALARMS FBD and highlight the FC1001_FLT_ALM ALMD element.

The error has occurred because the original FC1001_FLT_ALM was created with a scope of MainProgram and it cannot be accessed from the MainAlarmProgram.

In order to fix this problem, we will need to create the ALMD tag again at the Controller scope. Right-click on the FC1001_FLT_ALM tag and select the New "FC1001_FLT_ALM" menu option (or press Ctrl + W).

The New Tag form will appear. Ensure that the Scope field is set to FirstController and click on OK.

Next, we should remove the duplicate FC1001_FLT_ALM tag that exists in the MainProgram Scope. Under the MainTask and MainProgram folders of Controller Organizer, right-click on the Program Tags icon and select Edit Tags.

The Edit Tags table will appear; select the FC1001_FLT_ALM tag, right-click on the box to the left of the name, and select the Delete menu option (or press the Delete key).

We have now fixed the first error message; now, let's resolve the second. Clicking on the second error message in the error pane will take you directly to the Jump To Subroutine (JSR) reference within our MainProgram element's MainRoutine object to the DIGITAL_ALARM routine. The error is being displayed because the DIGITAL_ALARM routine is no longer in the MainProgram element's scope. Delete this Ladder Logic Rung by right-clicking on it and selecting Delete (or by pressing the Delete key while clicking on the rung selected).

Finally, we will Verify the program once more to ensure that we no longer have any problems.

From the drop-down menu at the top of RSLogix 5000, navigate to Logic | Verify | Controller.

Open your RSLogix 5000 project and navigate from the drop-down menu Tools | Export | Tags and Logic Comments.

The Export window will allow you to choose a location on your computer to save the CSV file that is produced. Select a location on your computer and click on Save.

The CSV file that was generated can be opened and viewed using MS Excel. Open the file using MS Excel and resize the columns to make the document easier to read.

From RSLogix 5000 Controller Organizer, right-click on a program and select the Export Routine… option.

Use the Export window file browser to select a location on your computer to save your L5X file. Click on the Save button to store the L5X file on your computer.

Open the L5X on your computer using Notepad by right-clicking on the file and selecting Open With…; then select Notepad from the list.

View the XML file in Notepad.

Open a Ladder Logic Routine by double-clicking on it in Controller Organizer (you can use the VALVES routine that we created earlier in the book).

Open the drop-down menu option by navigating to File | Print Options. Print Options allow us to modify the data that is printed and how it is displayed for the wide range of reports we can generate from RSLogix 5000 Review the available items in the Print Options window.

Under the Tag Listing list box item, click to uncheck the Expand Arrays option.

Return to Ladder Logic Routine and, from the drop-down menu, navigate to File | Print (or press Ctrl + P).

Open a Function Block Diagram by double-clicking on it in Controller Organizer (you can use the DIGITAL_ALARM routine we created earlier in the book).

We want our FBD routine to print to a standard 11 x 17 sheet of paper so that it can be included alongside our P&ID drawings. Right-click on the background of the FBD routine and select Properties (or press Alt + Enter).

Click on the Sheet Layout tab and, from the Sheet Size drop-down selection, click on the option Tabloid: 11 x 17 in. Then click on the OK button. This will also provide a much larger area to lay out your FBD routines.

Print the FBD by opening the drop-down menu and navigating to File | Print (or press Ctrl + P).

First, we will open our existing Ladder Logic Routine using Controller Organizer and double-clicking on the VALVES routine.

Select both the valve rungs and copy them to the clipboard by clicking on the numbers 0 and 1 while holding Ctrl and then right-clicking on the rung and selecting Copy Rung (or pressing Ctrl + C).

Next, open Notepad and paste the following copied rungs onto it by selecting Edit | Paste (or by pressing Ctrl + V):

NEQ(FC1001_PV,FC1001_SP)TON(FC1001_TON,?,?);
XIC(FC1001_TON.DN)OTL(FC1001_FLT);   

You will notice that the Ladder Logic has been copied in a programming language called Instruction List (IL), which is defined as part of the IEC 61131 standard. Now that the code is in plain text IL, we can edit and duplicate it more easily.

Now we will duplicate the code two more times for the remaining three valves we will add to our project. Copy and paste the following code two more times in Notepad:

NEQ(FC1001_PV,FC1001_SP)TON(FC1001_TON,?,?);
XIC(FC1001_TON.DN)OTL(FC1001_FLT);
NEQ(FC1001_PV,FC1001_SP)TON(FC1001_TON,?,?);
XIC(FC1001_TON.DN)OTL(FC1001_FLT);   NEQ(FC1001_PV,FC1001_SP)TON(FC1001_TON,?,?);
XIC(FC1001_TON.DN)OTL(FC1001_FLT);

Next, we will modify the tag prefix used on each copy we've made. Each tag of the first IL copy should be changed from FC1001 to FC1002 and so on:

NEQ(FC1002_PV,FC1002_SP)TON(FC1002_TON,?,?);
XIC(FC1002_TON.DN)OTL(FC1002_FLT);
NEQ(FC1003_PV,FC1003_SP)TON(FC1003_TON,?,?);
XIC(FC1003_TON.DN)OTL(FC1003_FLT);
NEQ(FC1004_PV,FC1004_SP)TON(FC1004_TON,?,?); XIC(FC1004_TON.DN)OTL(FC1004_FLT);

Next, we will copy all of our newly edited IL code in Notepad to our clipboard by selecting all of it and then navigating to the drop-down menu Edit | Copy (or by pressing Ctrl + C).

Returning to our RSLogix 5000 Ladder Logic Routine, we will now paste the IL code into our routine. Right-click on the last rung of our routine that has the (end) label and select Edit Rung (or press the Enter key). The Rung IL code editing text field will appear at the top of Ladder Logic.

Select the entire contents of the Rung IL code in the text field and press the Delete key to clear it.

Next, paste the code we've created in Notepad into the Rung edit IL code text field by right-clicking on it and selecting Paste (or by pressing Ctrl + V).

Now we will add our updated IL code to our Ladder Logic Routine by pressing the green check mark button beside the IL code edit form field.

We will need to add the missing tags and timer blocks before we can verify and download our application.

Expand the RSLogix 5000 Controller Organizer tab, find and expand the Data Types folder, and select the User-Defined node.

Right-click on the User-Defined node and select New Data Type….

The Data Type window that appears will allow us to configure our UDT. Enter the following name and description in the fields provided:

The data table under the Description UDT allows us to define the tags that will be included with each instance of the structure we've created. If we had created this UDT earlier, it would have saved us quite a bit of work creating all the tags for our various flow control valves (FC1001, FC1002, FC1003, and so on). Let's add our first tag to the table to replace our flow control valve position feedback variable FC1001_PV. Add the following values to the first row of the table:

Next, we can enter the remaining simple base types to the table as follows:

UDTs also allow us to create more complex base types inside them, such as the TIMER type and even other UDTs. Let's add the complex base type tags to our UDT TON: TIMER as shown in the following screenshot:

Click on OK to save our UDT. Now we have recreated all of our flow control valve tags in a single UDT.

Next, we will create an instance of our VALVE UDT and link it to our Analog In card channel. On Controller Organizer, right-click on Controller Tags under the Controller folder and select New Tag… (or press Ctrl + W).

In the New Tag window, enter the following values:

Click on the OK button to save the new tag.

Next, we will link one of the values of our UDT tag using Ladder Logic. Open the VALVES Ladder Logic Routine and add a new rung by right-clicking and selecting Add Rung (or press Ctrl + R).

Add a Move element to the new rung by selecting it under the Move/Logical element group.

Set the source of the element to FC1001_PV and set the destination of the element to FC1001.PV as shown in the following screenshot: