Many people ask me what I do when looking at a new PLC model or system. My approach is very straight forward and we will view this in action with this Click PLC series. This series will go from examining the hardware to programming and communicating to the PLC in several ways. If you have questions along the way, please let me know.
CLICK PLC Instruction Set Ladder Symbol Title Type Description Normally Open Contact Bit Instruction The Normally Open Contact mimics the behavior of a physical contact and changes in response to the status of a Bit Memory Address. The Normally Open Contact is ON when the related bit is ON. Normally Closed Contact is ON when Normally Closed. We will now look at the click plc advancedhmi Modbus serial communication. Advanced HMI is a powerful, adaptable HMI/SCADA (Supervisory Control and Data Acquisition) development package that takes advantage of Visual Studio.
Determine the Inputs and Outputs – Click Hardware
CLICK PLC Tutorials CLICK PLC - Getting Started - (2 Part Series) An introduction to CLICK PLCs and getting started with CLICK PLCs. CLICK PLC - How To Videos - (10 Part Series) 10 part video series: How to Install the Programming Software, Launch the Programming Software, Creating a Project, Save and Compile Project, Apply Power, Establish PC to PLC Communications, Write Project to PLC, Place. Welcome to the CLICK PLC Programming Software. Version 2.60 Feb 12, 2020 - This document describes some of the changes in this release of the CLICK PLC Programming Software. It also includes known issues as well as updated information for the documentation provided with the software. (VID-CL-0035) - The Click Micro PLC was designed for the PLC beginner. Its user interface is tailored to reduce.
The five steps to PLC program development will determine the inputs and outputs required in our system.
1 – Define the task
2 – Define the inputs and outputs
3 – Develop a logical sequence of operation
4 – Develop the PLC program
5 – Test the program
There are several reasons why we are using the Click PLC. Here are just a few.
– Investment is low for the hardware and the software is free
– Standalone PLC with built-in I/O
– Communication ability – Ethernet Port, RS232, RS485 – support for protocols such as Modbus RTU, Modbus TCP, etc.
– Ability to expand the system with a variety of modules including RTD and Thermocouple inputs directly.
The following should be downloaded from the Automation Direct Website.
Click PLC User Manual – You can download the entire manual or just the sections that you need at the time.
https://www.automationdirect.com/adc/Manuals/Catalog/Process_Control_-a-_Measurement/Temperature_-z-_Process_Controllers
Click PLC Software – This is required to configure, program and document your Click PLC.
http://support.automationdirect.com/products/clickplcs.html
Configuring the Click Hardware System
We can now build our PLC system from the following website.
http://www.automationdirect.com/adc/Shopping/Catalog/Programmable_Controllers/CLICK_Series_PLCs_(Stackable_Micro_Brick)
The Click PLC unit currently comes in 5 different types. The following table will show the different units:
A system can have up to eight (8) additional units connected to it. The following shows a picture of a system that has the maximum amount of units.
Each unit can be any of the following:
DC I/O – These units can be wired up either sinking or sourcing. (NPN / PNP) This applies to both the input and output units.
AC I/O – 100 – 120 VAC, 24VAC/DC, Relay Outputs, 17-240VAC Outputs, and combination output units are available.
Analog I/O – The standard 0-20mA, 4-20mA, 0-10VDC inputs, and outputs are available with either 12 or 13-bit resolution. There are also temperature input modules that accept 4 RTD or thermocouple inputs.
Wiring our Click PLC Hardware
Additional resources on wiring:
https://accautomation.ca/heres-a-quick-way-to-wire-npn-and-pnp-devices/
https://accautomation.ca/get-rid-of-surges-that-are-destroying-your-plc-outputs/
https://accautomation.ca/the-secret-of-getting-rid-of-noise-on-your-analog-signal/
All of the PLC units need 24VDC power to operate. The maximum amount of current required on the power supply is 1.3 amps. This will cover any combination of I/O modules requirements of the Click PLC.
The free Click Programming software has a Setup | System Configuration menu that will show you the modules used and supply power required. This is also where we can configure the analog and see the addressing of the physical I/O.
The Click PLC that we will be using is the C0-11DRE-D. It has three communication ports, 8 input, and 6 output points. We also have an analog module C0-4AD2DA-2. This is a combination module that has 4 input points (0-10VDC) and 2 output points (0-10VDC). The power supply is a C0-01AC. This will cover any combinations that we require on our PLC.
Note: The analog will give you a range. We can configure the module using the Click Programming software to set the physical range and the scaling factors without the need for programming.
Connection to the PLC will require cables. Our PLC has three different communication ports. All three are capable of programming our unit with the Click programming software. Here is the link to get the pinout of all of the cables.
http://www.automationdirect.com/static/specs/directsoftcables.pdf
The most common method is to use RS232. A RJ12 port is used on the PLC to communicate. If your computer has a DB9 (9 pin D-shell male) serial connector then you can use the D2-DSCBL cable.
Most computers will not come with serial ports anymore. So we can still utilize the RS232 communication by using a USB port. The EA-MG-PGM-CBL will connect to your USB port and convert to RS232 to communicate.
RS485 can be utilized by using the USB-485M converter. This will communicate from your USB port convert to RS485 and communicate to the RS485 port (2-wire) on the PLC.
https://accautomation.ca/usb-to-rs485-pc-adapter-installation/
The Ethernet cable connection is by far the quickest to communicate to the Click PLC. It uses a standard RJ45 Ethernet connection.
Next time we will install the software and communicate to the Click PLC in three different ways. RS232 RS485 and Ethernet.
Watch on YouTube: Click PLC System Hardware
Watch on YouTube: Wiring (Testing) Analog PLC Input Click
If you have any questions or need further information please contact me.
Thank you,
Garry
If you’re like most of my readers, you’re committed to learning about technology. Numbering systems used in PLC’s are not difficult to learn and understand. We will walk through the numbering systems used in PLCs. This includes Bits, Decimal, Hexadecimal, ASCII and Floating Point.
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The program control instructions will allow us to specify what parts of the logic get solved and when this happens. This will control how the PLC will scan and solve your logic in your program.
Previously in this series we have discussed:
System Hardware – Video
Installing the Software – Video
Establish Communication – Video
Numbering System and Addressing – Video
Timers and Counters
– Counter Video
– Timer Video
Compare and Math Instructions – Video
The programming software and manuals can be downloaded from the Automation Direct website free of charge.
Click PLC Program Control Instructions
Program control (flow) instructions in the Click PLC will utilize interrupts and subroutines. In the last post on Click PLC Compare and Math Instructions, we discussed interrupts. They can be timed or event (Built-in inputs on the CPU.) When the interrupt happens it will immediately go and solve the logic in the interrupt and then return to the instruction following the location that it was called. This can and will happen at any time throughout the scan of the PLC.
Interrupt – Click Program Control
Let’s take a look at an example of an interrupt. We will flash an output on for 3 seconds and off for 3 seconds. A review of entering interrupts can be found in our last post. Click PLC Compare and Math Instructions
Click Plc Software Manual
We will be using software interrupt 1. The interval time will be 3 seconds and it will call up our interrupt routine called ‘Flasher 3sec’.
Here is the interrupt program quick guide that will be displayed as a reminder of the way in which interrupts are used.
The code that we use for the flasher is just a normally closed contact going to the output of the same contact. Since this logic will only execute once every three seconds, it will alternate the output on and off.
Subroutines – Click Program Control
Subroutines are blocks of code that will get executed when they are called from the main program. This differs from the interrupt because with subroutines we have complete control of when it will be executed in relation to the main program. In the Click PLC, we can have 986 subroutines. This means that we will have 986 calls or more in the main program to execute the code in the subroutine. We cannot have nested subroutines. This means that each subroutine must return to the main program. It cannot call another subroutine.
When a Subroutine program is not called during a scan of the main program the memory bits and data registers within the subroutine will maintain their status unless some other part of the program changes their status or data.
The purpose of subroutines is to organize your code into manageable pieces. These pieces can also be re-usable. The readability of your PLC program improves when using subroutines because you are just looking at smaller pieces of code. The alternative would be all of the rungs in just the main program. This is hard to read and especially troubleshoot when things are not working.
Here is what happens when scanning the program:
- Main program logic is scanned/solved until it reaches a subroutine call
- Subroutines logic is scanned /solved until it reaches the return statement
- The main program logic continues to scan/solve with the rung that follows the subroutine call
- This will continue until the End statement is read which will then complete the rest of the PLC scan and start again
Note: Interrupt routines can happen at any time and the logic will continue to be solved after the logic of the interrupt is executed.
Subroutine Example – Click Program Control
Let’s look at an example. We will have two motors that need to be controlled. Each motor will have a start, stop and jog push buttons.
The first thing that we will do is make our subroutines. (Motor 1 and Motor 2)
To make a new subroutine, you can do one of the following.
Main Menu – Program | Add new subroutine program…
Keyboard Shortcut – Control ‘U’ – CTRL+ U
Navigation Window – Right Click on ‘Subroutine Program’ and select ‘Add New Subroutine Program CTRL+ U’
Enter the name of the subroutine. (Motor 1) Hit OK. The subroutine program quick guide will now appear. It will remind us of how to use the subroutine program. Hit OK.
Under the navigation window, we will now see our subroutine Motor 1. Double click on it and we will enter the following code for motor 1.
You will notice that the subroutine background defaults to green. The interrupt background is red. This can be changed by going to the following menu selection. Main Menu – Setup | Software Setup…
Now repeat the steps above for another subroutine for motor 2. It should look like the following:
Under the navigation window, double-click the main program. We can now call our subroutines that we have just made in the main program so that they will execute. We will use unconditional rungs and the ‘Call’ instruction. Enter the following on the main program.
Note: Since we created our subroutines before using the call instruction they are available in the pull down menu of the instruction. We could also have added a new subroutine by this same instruction.
Looking at the navigation window we can see our two subroutines and interrupt the program.
Click Plc Software Download
Download the Click PLC Program Control sample PLC program.
Controlling our program is easy with subroutines and interrupts. The advantage is that our program will also be easier to read, understand and troubleshoot.
Next time we will look at shift register instruction.
Watch on YouTube: Click PLC Program Control Instructions
If you have any questions or need further information please contact me.
Thank you,
Garry
If you’re like most of my readers, you’re committed to learning about technology. Numbering systems used in PLCs are not difficult to learn and understand. We will walk through the numbering systems used in PLCs. This includes Bits, Decimal, Hexadecimal, ASCII, and Floating Point.
To get this free article, subscribe to my free email newsletter.
Use the information to inform other people how numbering systems work. Sign up now.
The ‘Robust Data Logging for Free’ eBook is also available as a free download. The link is included when you subscribe to ACC Automation.