ET 401 – Lab 3– Using the AutomationDirect CLICK PLC

ET401 – Lab 3Using the AutomationDirect CLICK PLC

In this lab we shall basically repeat last week's lab but use a real PLC—the AutomationDirect CLICK PLC—insteadof the PLC Fiddle simulator. The CLICK PLC is on a trainer that we designed and built especially for MMA.

All PLCs come with software that is used to write the program for the PLC. This is done on a PC and then transferred to the PLC. To write this program, you need to be a bit familiar with the PLC's host programming software. You will find, however, that it has some similarity to the simulation interface of PLC Fiddle.

The CLICK PLC is a low-cost series of PLCs that have, however, a great deal of functionality. The program to construct the PLC ladder can be found at https://www.automationdirect.com/clickplcs/free-software/free-click-software. You can download the software from this webpage. It is cost-free. There is no version for the Apple iOS. Sorry. If you have an Apple, get used to this, for it is often true with specialty software in the engineering world. I suggest you save some money, sell the Apple, get a Windows PC. That may seem harsh, but this has been the case for at least 30 years: often engineering software comes out for the Windows

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ET 401 – Lab 3– Using the AutomationDirect CLICK PLC

environment before it does for the Apple iOS, and often it never comes out for the Apple iOS. A Mac just is not suitable as a general-purpose computer for engineering applications.

The user interface for the CLICK programming software is shown below.

There is on-line Help to learn how to use the program to write a ladder-logic program. Here is a link to the Helpfiles for the CLICK software:

https://www.automationdirect.com/clickplcs/free-software/software-help

To the right of the ladder you will see components that can be used in the ladder. Under Contacts you will see that AutomationDirect unfortunately uses NO for a MAKE and NC for a BREAK. You’ve been told never to do this. NEVER DO IT! It is confusing. I wrote them the following message on their response board:

I think it is confusing to call a MAKE instruction a normally open contact and a BREAK instruction a normally closed contact. In fact I have seen this confuse many, many newcomers to PLCs. The fact is that you can connect a normally closed pushbutton to a MAKE, making it allow logic to flow through and a normally open pushbutton to a BREAK instruction, allowing logic also to flow through if unactuacted. The terms NO and NC should only be applied to the actual input hardware, never to the PLC internal instructions!!! Please, please change this terminology to MAKE and BREAK (which are better, in my opinion, that the confusing XIC and XIO terms you see on Allen-Bradleys). A great discussion of this is in JimPytel's video on the Big Bad Tech Channel (YouTube): https://www.youtube.com/watch?v=ic9crSVVF9Q&list=PLkxqHEyjiG_k0JKUwTL61f5OZ8Ws-rOWm. I made the mistake of confusing these when I began and only came to understand after I'd watched this video.

Hook the PLC up to your PC

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ET 401 – Lab 3– Using the AutomationDirect CLICK PLC

Once your have the CLICK software downloaded and running on your PC, turn the PLC on with the light switch on the trainer board. At some point you will be asked to choose the AutomationDirect PLC that you are running. You can find the model on the PLC itself. It is a D0-01DR-D. The dialog box to select this is shown.

You need to set up communication between the CLICK PLC and your computer. There is a special cable for this.Hook it up to Port 1 or Port 2 on the PLC, and then hook the other end into a USB port on your computer.

The CLICK user interface appears as shown below. This shows and empty ladder, with the graphical cursor in the first position on rung 1. Choose what contact you want to install here, from either the choices in the panel on the right or the contacts arrayed under the ladder. You drag the ones in from the right, whereas you just click on the ones below to install them.

Once you write a program, you will want to compile it and then download it to the PLC. Make sure that the PLCis connected to the PC by choosing the menu item PLC/Connect… . If the computer does not see the PLC, movethe USB cable to another port on your computer and try again. Then, with the PLC connected, you can download programs (Projects) into it.

One thing that is different about CLICK programs vs. PLC Fiddle programs is that the CLICK programs must end with a single, empty rung with an END instruction. This is put where normally the coil is put, i.e. on the right-hand side of the ladder, as the last rung.

Once you write a program in the CLICK software, you need to load the project into the PLC. To do this, you need to have the PLC in STOP, not RUN, mode. There is a switch on the PLC to go between these two modes. With the PLC in STOP mode, you should see a yellow STOP indication in the CLICK software:

Now choose PLC/Write Project into PLC… to load your program into the CLICK. This will be confirmed when the

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ET 401 – Lab 3– Using the AutomationDirect CLICK PLC

process is complete.

For each of the exercises below, save your Project, so that you can recall it and rerun it later if you need to.

Exercise 1: Orientation to CLICK PLC

First, to orient yourself to the CLICK PLC determine by experiment what switch/button is hooked to what light. In this also you will have to determine which position of the switches/buttons is on. There are, of course, four retentive switches and then two momentary pushbuttons. For the pushbuttons, are they NO or NC?

There are six lights but only five buttons. Figure out a way to light up the sixth light if both momentary pushbuttons are pushed at the same time.

Figure all of this out and then have a lab instructor verify it.

Exercises 2-8: All of the exercises from last week, but on the PLC

Do not do Exercise 3 from last week. You will complete it along with Exercise 7 from last week below.

You will only have to do Exercise 4 from last week, not Exercise 5, since there is a NC pushbutton on the trainer.

In lieu of last week's Exercise 7, create a ladder that uses the six lights to illustrate, in this order OR, NOR, AND, NAND, XOR, NXOR.

Note that when running your programs, you can see what’s going on inside the PLC ladder using the Monitor/Status menu item. Try this feature out.

Exercise 9 – Program problem 0.4 from the book into the CLICK PLC

Once you complete all of the exercises above, program Exercise 0-4 in the book onto the CLICK PLC. We shall fake the sensors with the input switches. Let S1 be the high-level sensor and S2 be the low-level sensor. For the outputs, let L1-3 be your Red, Yellow, and Green lights. Use the Green and Red lights on the right-hand box to represent the Pump, whether it is off (Red) or on (Green). Start with the pump not running, with the level in middle, rising. Operate the high-level sensor by hand to show that the level rose to the high-level sensor. After a little bit of running, turn the high-level sensor off. Let the pump pump the water in the tank down. Then turnon the low-level sensor for a little. Then turn it off once the pumps shuts down and the level starts rising again.

Exercise 10 – Program problem 0.5 from the book into the CLICK PLC

Follow the instructions. Use the Red and Green lights on the left-hand box to indicate the valve's state. Set thisup to demonstrate as you did in Exercise 9.

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