Introduction to Allen Bradley PLCs - RSLogix 500

Introduction to Allen Bradley PLCs - RSLogix 500

Allen-Bradley PLCs are a popular brand of automation controller used throughout the world for machine control, process control, and motion control.

There is an extensive line of Allen-Bradley PLC models for any application, from the small, compact MicroLogix PLC to the mid-sized CompactLogix series, to ControlLogix, a logical choice for large, complex control systems.

In this section, we will introduce you to the Logix family of PLC processors from Allen-Bradley, a division of Rockwell Automation.

We will show how to obtain a free copy of the programming software RSLogix 500 Micro, the communication driver RSLinx, and RSEmulate.

Introduction to Allen Bradley PLCs - RSLogix 500
  • 1. What is Allen Bradley PLC - Introduction

    Allen-Bradley PLCs are a popular brand of automation controller used throughout the world for machine control, process control, and motion control.

    As with Siemens or ABB PLCs, there is an extensive line of Allen-Bradley PLC models for any application, from the small, compact MicroLogix PLC to ...

  • 2. Common Allen-Bradley PLC Models

    Allen-Bradley PLCs all feature modular construction and many options for customizing the hardware to my needs. Integral communication protocol options include a DFI Serial interface and Ethernet/IP. These protocols are used to communicate to other PLC processors, remote I/O racks, and networked d...

  • 3. Installation and I/O

    All Logix controllers provide DIN-rail mounting convenient for panel installation. Logix controllers can be extended using remote I/O modules, from 144 I/O with a MicroLogix 1100 CPU to over 128,000 I/O for a ControlLogix 5580 processor.

    CompactLogix and ControlLogix processors have options for ...

  • 4. Software Used for Programming Allen-Bradley PLCs

    The MicroLogix processors are programmed using a software package called RSLogix 500.

    The version of RSLogix 500 used for this course is an older version that supports the MicroLogix 1000, which has been discontinued, and the MicroLogix 1100.

    We are using a specific “Micro Lite” version because...

  • 5. Downloading RSLogix500 Software

    In this course, we will use a free version of RSLogix 500 to program and simulate a MicroLogix 1100 PLC. To obtain the software, go the website:
    At the landing page, click the magnifying glass to start a search. Type in “RSLogix Micro”.

    When the pick...

  • 6. A Tour of RSLogix 500

    In this video, we will take a quick tour of RSLogix 500.
    The tool ribbon is displayed in two parts.
    The left half shows the online status of the program and the status of program forces. The picture of the ladder with the connected boxes will animate and rotate when RSLogix is connected and the P...

  • 7. Configuring the PLC Processor

    In this video, we will create a program file!
    We will select the Bulletin 1763 MicroLogix 1000 Series B processor to develop an example that will control a ball mill, fan, and oil pump in a slurry process.
    In the project tree, we have:

    - Controller configurations, such as passwords and communic...

  • 8. Data File Concepts

    The PLC processor contains several areas of memory.
    The program memory is where the program instructions are stored. Values of I/O points and internal memory, such as bit values, integer values, floating-point values, timers, and counters are organized in Data Files, separated by type of data.

  • 9. IO Concepts

    There are two data files, O0, which stores values from digital output cards, and I1, which stores values from digital output cards.
    The addresses within each data file are set by the I/O rack and module in which the I/O card resides.
    The MicroLogix 1100 comes with 10 digital inputs, 2 analog inp...

  • 10. Forcing File Concepts

    There are two special files, called forcing files, one for inputs and one for outputs.

    These files are used for troubleshooting or when I/O is not available, such as when a sensor fails.
    The forcing files allow the value supplied by the I/O subsystem to be over-written by the programmer in ord...

  • 11. RSLogix File Structure

    In the last lesson, we briefly described the data files. Now, we will describe these files in more depth and show how they are used.

    Note that each data file is described by a letter followed by a number.

    The letter indicates the type of data represented by that file, and the number represents ...

  • 12. Output Files

    Output file 0 and Input file 1 are defined to hold values from physical I/O cards.

    All of the data files are presented in much the same way. The Output file holds values that are associated with physical output cards. For a MicroLogix 1100, up to 64 outputs, or four 16-bit output words, can be ...

  • 13. RSLogix Input Files

    The structure of the Input file is the same as the Output file.

    File I1 represents the physical input device addresses possible.

    Notice that there are six 16-bit input words available, representing the possible 96 inputs for the PLC.

    In a later lesson, we will add descriptions and symbols f...

  • 14. RSLogix Binary Files

    Binary files are structured very much in the same way as the Input and Output files.

    Upon inspection, the only obvious difference is that the Binary file window does not have the Force button at the bottom of the window.

    The other difference is in the way the address in the Binary file is show...

  • 15. RSLogix Data Files

    In the previous section of this course, we gave a tour of the RSLogix 500 output, input, and binary files. We demonstrated how individual elements of these file types are referenced, how to change the view of the data file from bitwise to decimal, and how to expand the size of certain data file t...

  • 16. Timer Data Files

    The elements for the single timer that is configured by default include EN, TT, DN, BASE, PRE, and ACC.

    A timer is used to control the timing of a logic event.

    For a MicroLogix 1100, the Preset element can be set from 0 to 32767.

    Each timer requires three words of memory.

    The first word hol...

  • 17. Counter Data Files

    The counter structure is similar to that of the timer because it also has a preset and accumulator value, also called PRE and ACC.

    There are several bits that are set by the counter, including:

    CU for counting up,
    CD for counting down,
    DN to indicate that the counter has reached the preset val...

  • 18. Control Data Files

    Control files are used in conjunction with complex data functions, like FIFO Load, Sequencer, and Bit Shift Left.

  • 19. Integer Data Files

    File 7, the Integer file, is structured just like the B3 binary file, except the data is integer data.

    An integer may have a value of -32768 up to 32767.

    Just as with the Binary file, we can change the Radix to view the data in its binary form.

    As part of the ladder program, we can use the in...

  • 20. Floating Point Data Files

    F8 is the floating-point data file.

    Floating-point data cannot be shown in any other manner than floating-point, or real number notation.

    Floating-point numbers greater than 9,999,999 are shown in scientific notation.

  • 21. Adding a New Data File

    To add another data file, right-click on the Data Files folder in the project tree and select New.

    Change the file number to 20, then select Integer as the file type from the drop-down menu.

    Give the file a name, update the number of elements, and select OK.

    You can see the newly-created N2...

  • 22. RSLogix 500 Online and Offline Modes

    In Offline mode, we are not connected to a PLC or simulator, and the program file is available for program changes without consideration of how the changes would affect an operating program.

    Changes made in Offline mode will need to be downloaded to the PLC processor before they can be executed ...

  • 23. Adding Rungs to the Program

    There is an instruction at the right-hand side of the rung named “END”. “END” is an instruction when executed, which will cause the execution of the program file to end for the current program scan.

    This rung is normally the last rung in the program file.

    The “Insert Rung” command adds a rung ...

  • 24. Adding Instructions to Rungs

    We want to increment an integer value every five seconds. Once we count up to 10, we want to reset the integer to zero and start over again.

    We will add Equal instruction and CLR instruction to the ladder program.

    We will add addresses, comments, and symbols to rung instructions.