Category Archives: PLC Applications

PLC vs. DCS: What’s the difference?

Before we get into the differences of a PLC’s and DCS’s, we need to talk about what each of them are designed to do.

What is a PLC?

A PLC, or Programmable Logic Controller, is a computer that has been adapted to specifically meet the needs of any specific manufacturing process. These devices come in many different shapes and sizes, with many options for digital and analog I/O, as well as protection from high temperatures, vibration, and electrical noise. The invention of the PLC allowed computers to be streamlined into the industrial automation process.

A PLC can be a single device calculating and executing operations, or a rack of different modules may be used to meet whatever your automation system requires. Some of the additional components include processors, power supplies, additional IO, interfaces, and much more.  Every part works together to be able to run open or closed loop operations that are rated at high speed and high precision. Take a CNC machine for example; a PLC would be used to control positioning and motion, as well as torque control. These devices are popular because they are very inexpensive relative to the amount of power and how many hours you get out of them.

 What is a DCS?

A Distributed Control System is an automated control system that streamlines the functionalities of the various devices that are used throughout an entire work space. This type of system uses many different controllers to allow all the machining parts to talk to each other as well as computers that can input parameters and display information such as power usage, speed, and much more. These controllers are distributed geographically across a plant to allow for high-speed communication to the control room. When using different types of modules however, the system may require different communication standards such as Modbus and Profibus. DCS’s started coming to fruition throughout the 1960’s once the microcomputer was brought widespread into the market.

Then what exactly is the difference?

A PLC will probably be used to control a machine that isn’t too complex wheres the DCS can have total control of all the operations in an entire plant. The PLC is preferred in situations where the machine does not have to worry about meeting specific conditions inside the plant. These conditions typically involve operations that may need to stop or restart, as well maintaining precise temperatures. A DCS will be able to take advantage of all the aspects of an automated system, from the machines and sensors to the controllers and computers. An entire DCS is much more expensive than a few PLC’s, but each have their advantages in any given situation and certain automated systems will always require one over the other.

Visit MRO Electric and Supply’s website to see all of our available Programmable Logic Controllers. If we don’t have what you need listed on the site, contact us at sales@mroelectric.com or (800)691-8511 and we will be happy to help.

Considerations for buying automated parts

What are automated parts used for?

Automation is crucial in manufacturing and is the backbone of our industries. Robots can automate highly variant, dangerous and exhausting tasks in a high-quality and cost effective way. By increasing productivity at a lower cost, maximum cost efficiency is reached, which is ideal in a business setting.

What should I be looking for when buying automated parts?

There are a number of things to keep in mind when buying automated parts for your warehouse or setup. Below is a basic guide with questions to ask yourself to make the process a little easier.

Is there a warranty? If so, for how long?

Protect your investment on your automated parts. Warranties are important in insuring that your part is functioning as intended and in getting what you paid for. Make sure you check under what instances a warranty can be claimed and how long the warranty lasts. Are there detachable parts within the automated component that are covered? MRO Electric and Supply offers a minimum 12-month warranty on all listed parts.

Is the part compatible with the machinery that is already there?

There are a multitude of environments that certain parts can be more oriented towards, including in aerospace and automotive manufacturing, food processing plants or laboratories. It is essential that the part be used in the correct application to be effective. It is obviously important that the automated component works with the setup already in place. Some additional compatibility questions to ask yourself before buying:

Does the weight or form factor impact its compatibility? Is space an issue?

Many people are eager to buy large parts for their warehouses without considering the space to put them. Consider the part and its intended configuration. Include additional equipment that comes along with the part like peripherals, fencing, light curtains or mat guards.

Will the condition of the part affect its lifespan in this application? Is there a newer, better part for this application?

Check to see if the part is new, used or refurbished, and if the condition will affect its application. Many industrial parts are discontinued as new technologies evolve, and while these legacy parts are still useful, newer components might work more efficiently or effectively. Check to see if there are any advantages or disadvantages to older and newer generations of your part and weigh your options.

Visit MRO Electric and Supply’s website to see our selection of automated parts from manufacturers like Yaskawa, Modicon, Control Techniques, Siemens, and FANUC. If we don’t have what you need listed on the site, contact us at sales@mroelectric.com or (800)691-8511 and we will be happy to help.

Modicon PLC History

Modicon PLC History

Modicon PLC History

Richard E. Morley, also known as Dick, was an American electrical engineer. He was an employee at Bedford and Associates, located in Massachusetts. He is most commonly known for his involvement with the production of the first Programmable Logic Controller (PLC) for General Motors and the Modicon in 1968. General Motors Company, often referred to as GM, is an American multinational corporation that is headquartered in Detroit, Michigan that engineers, manufactures, markets and distributes vehicles and vehicle parts and sells financial services.

Known as an author, educator, influencer and specialized engineer, Morleys’ accomplishments and contributions have earned him numerous awards from families such as ISA (the instrumentation systems and automation society), Inc. Magazine, Franklin Institute, SME (the Society of Manufacturing Engineers), and the Engineering Society of Detroit. SME offers the Richard E. Morley Outstanding Young Manufacturing Engineer Award for outstanding technical accomplishments in the manufacturing space by engineers age 35 and younger.

Schneider Electric currently owns the Modicon brand of PLCs. The PLC has been recognized as a major advancement in the automation space and has had an unprecedented impact on the manufacturing community as a whole. PLCs were designed to replace re-wiring and hard-wired control panels with software program changes when production updates were necessary. Before PLCs came about, several relays, drum sequencers, cam timers and closed-loop controllers were used to manufacture vehicles and vehicle parts. Re-wiring the relays and other necessary components was a very in-depth and costly process, but clearly worth the effort. The Modicon 084 PLC was modeled to be programmed in ‘ladder logic’ which had the look of the schematic diagrams of relay logic it was replacing.  This made the transition to PLCs easier for engineers and other professionals in the manufacturing space.  The automotive industry is still one of, if not the largest users of PLCs today. MRO Electric and Supply has new and refurbished Modicon parts available including the Modicon Quantum series. We also offer repair pricing. For more information, please call 800-691-8511 or email sales@mroelectric.com.

The Modicon PLC Timeline

A few years later, in the 1970’s, dialogue between PLCs came about. Introduced as the first industrial communications network, Modbus was based on a Slave/Master architecture that used messaging to communicate between Modbus nodes. All and all, a lacking standardization made PLC communications a nightmare.

In the  1980’s, General Electric made an effort to regiment the interconnection of devices from several manufacturers with MAP (manufacturing automation protocol). PLC programming software was also created to operate on personal as well as professional computers in order to remove the need for dedicated programming terminals or handheld programmers.

As years have gone on, PLCs have evolved as technology evolves. Nowadays, they include process, motion, and distributed control systems, as well as complex networking. Equivalent to an average, run-of-the-mill desktop computer, PLCs have capacities for data handling storage and impressive processing power.

PLC Security

plc security

PLC Security

Programmable logic controllers, also known as PLCs, initially came about in the late 1960s. PLCs were designed to replace relay-based machine control systems in the major U.S. vehicle manufacturing space. The relay-based control systems were considered hard to use and were disliked amongst those in the automation and manufacturing in.

In 1968, Dick Morley of Bedford Associates in Massachusetts designed the Modular Digital Controller, later dubbed the Modicon. After the Modicon 084’s initiation into the world, there was no looking back to those relay-based control systems. Be sure to check out our article covering Modicon PLC history to learn more.

PLCs are user-friendly microprocessor-based specialty computers that carry out control functions, many of which are of high levels of complexity. They are engineered to endure harsh and strenuous situations such as in heated, cooled and even moist environments. Used for automation usually in the industrial electromechanical space, PLCs are computers that deal with the controlling of machinery, often on  the following:

  • factory assembly lines
  • power stations
  • distribution systems
  • power generation systems
  • gas turbines

PLCs are programmed using a computer language. Written on a computer, the program is then downloaded to the PLC via a cable. These programs are stored in the PLCs memory. The hard-wired logic is exchanged for the program fed by its user during the transition between relay controls to PLC. The manufacturing and process control industries have gotten to take advantage of PLC applications-oriented software since Modicon PLCs inception.

plc security
PLC Functions and Directions

PLCs use programmable memory in order to store particular functions and directions. Some functions and directions would include:

  • on control
  • off control
  • timing
  • sequencing
  • counting
  • arithmetic
  • data manipulation
PLC Types

Understanding the different types of PLCs will be very helpful when looking into PLC security.

The numerous types of PLCs can be organized into three principal categories:

  • Advanced PLC: Advanced PLCs offer the greatest processing power out of all of the PLC types. They feature a larger memory capacity, higher input/output (I/O) expandability, and greater networking options.
  • Compact Controller: Logic Controllers are increased intermediate level offerings with an increased set of instructions and a greater input/output (I/O) than a run-of-the-mill logic controller
  • Logic Controler: A logic controller is often referred to as a ‘smart relay’. They are generally straightforward to use and considered a good place to begin when becoming acquainted with PLCs. They are cost-effective for low input/output (I/O), slower speed applications.
PLC Security

As security concerns remain in many professional spaces including the factory automation space, becoming up-to-speed with the different types of PLC Security is imperative. By creating and implementing an effective strategy to remain secure, you will likely avoid issues, downtime, and setbacks. Understanding the different types of PLCs will be very helpful when looking into PLC security.

PLC Cybersecurity: How the control network is linked to the internet, as well as other networks. A handful of PLC issues could likely involve the following:

  • Incident response planning and plans;
  • Issues drafting and reviewing policies
  • Issues drafting and reviewing procedures
  • Retention of cybersecurity experts and vendors;
  • A need for preparation of a breach:
    • exercises
    • training
    • breach simulations
  • A need for cybersecurity insurance review and counseling
  • A demand for record management and information infrastructure;
  • Privacy risk management
  • Assessment of cybersecurity risk in mergers and acquisitions;
  • Payment Credit Industry (PCI) Compliance protocols
  • Vendor contract management protocols
  • Supply chain risk management

PLC Physical Security: Although PLC physical security differs from PLC cybersecurity, it is still important and should be prioritized when an individual or a company is undergoing breach simulations, training, and exercises. PLC physical security deals with:

  • correcting default passwords
  • ensuring only certified individuals are in the control system’s environment
  • limiting access to thumb drives and securing access

MRO Electric and Supply maintains a comprehensive stock of Modicon PLC parts, including the Modicon Quantum series. Also, feel free to check out our repair and core exchange programs to learn how to save.

Understanding Issues with Security
In order to create and implement training and procedures for staff, you must understand how issues with security occur.  Not all cybersecurity attacks occur from external hackers or scammers. In fact, experts believe that only an estimated 20% of all cybersecurity attacks are intentional and intended to be malicious. Whether you think it’s possible or not, an offended employee could indeed be your hacker. Almost always caused by software issues, device issues, and malware infections, cybersecurity seems straight-forward initially, until you dig into those fine, often overlooked details.

As many in the automation space may know, PLC cybersecurity wasn’t a thing a decade ago. These days, PLCs are connected to business systems through any run-of-the-mill network and aren’t separated from other networks that other automation equipment may also be on.  As time goes on, it’s becoming more and more common to see TCP/IP networking from a business system standpoint. By connecting via TCP/IP, data exchange, as well as more rational and scalable business decisions, is enabled.

PLC Security Factors:
  • Although it may not actually connect to the internet, a control system is unsafe. Contrary to popular belief, a modem connection could also experience intrusion and a hack.
  • Wireless networks, laptop computers, and trusted vendor connections could be other sources of connections in which people may be likely to overlook.
  • Keep in mind that the majority of IT departments are unaware of factory automation equipment, including CNCs, CPUs, PCBs, robotics parts and, last but not least, PLCs.
  • Piggybacking off of the last point, IT departments’ lack of experience with the aforementioned equipment, along with their lack of experience with industrial standards and scalable processes indicate that they should not be in-charge and responsible for a company’s PLC security. Nobody wants an annoyed employee to make inappropriate changes to a PLC’s communication highway.
  • Hackers do not necessarily need to understand PLC or SCADA to block PC-to-PLC communication. They absolutely do not need to understand a PLC or SCADA system to cause operational or programming issues.
  •  Often times, control systems, including ones that many PLCs integrate with, use Microsoft Windows, which is very popular amongst hackers.
  • Some PLCs crash simply by pinging an IP address, like what happened at the Brown’s Ferry Nuclear Plant, which is located in upstate Alabama. Since the incident in 2006, the plant has undergone numerous security, operational, and management improvements.

In conclusion, when a security breach occurs, regardless of the specifics, understanding that time is of the essence will help smooth over most incidents. Trusting who has access to a control systems environment and thumb drive is crucial. If someone has access to the control system environment and thumb drive, ensure they’re well-qualified and up-to-speed with their team and/or company.

plc

How to maintain a PLC (Programmable Logic Controller)

How to maintain a PLC (Programmable Logic Controller)

As many of us know, PLCs (programmable logic controllers) are staples in the factory automation world. In order to have them running optimally and as efficiently as possible, routine maintenance is imperative. Generally, manufacturers produce PLCs to endure strenuous, unsterilized environments. By adhering to an adequate maintenance schedule, PLCs operating timeframe can be lengthened.

Protect your PLC

Always be on the lookout for corrosive and conductive contaminants that have the potential to become a detriment to a PLCs’ components. By completing visual inspections for black dust and blowing airborne particles from the PLC’s vicinity, you are lowering the likelihood of contamination.

Is power flowing?

A PLC will not operate correctly without adequate power. To avoid any operation bugs, remain vigilant of any surges or shorts.

Calibrate Analog Components

Always refer to the preventative maintenance schedule for any analog input device. Analog inputs need to be cleaned regularly and calibrated as accurately as possible.

Take EMI into consideration

EMI (electromagnetic interference) is known to cause horrible issues for PLCs without clearly indicating what the specific issue is or how to go about fixing it. To remain ahead of the game, many perform an audit of the local wiring to pinpoint potential EMI sources before they interfere with the operation of your PLC. Lower-level components and high-current wires often interfere with each other, which wiring designs must take into consideration.

Additional PLC Maintenance Tips

By creating a PLC maintenance checklist and adhering to it strictly, operating errors can likely be avoided. The space between the PLC and the machine it’s controlling should be minimal.

MRO Electric and Supply has new and refurbished Modicon PLC parts available here. We also offer repair pricing. For more information, please call 800-691-8511 or email sales@mroelectric.com.

HMI-STU-855

Modicon Magelis HMI-STU-855 (HMISTU855) Product Spotlight

The Schneider Electric / Modion HMI-STU-855 is a 5.7 inch touch panel screen with a Magelis operating system and CPU ARM9 processor. It uses a QVGA TFT color touchscreen with a pixel resolution of 320 x 240 pixels. It uses an external supply source of 24 volts and consumes 6.8 watts of power. It has 16 MB of application battery with 64 kB available to back up data. The HMISTU855 is able to download a number of protocols including Modbus, Modbus TCP/IP, Uni-TE, and 3rd party protocols.  When using the HMISTU855, all connections to the communication ports on the bottom and sides of the unit must not put large amounts of stress on the ports. Be sure to securely attach communication cables to the panel or cabinet. Use only RJ45 cables with a functioning locking tab.

Critical detected alarm indicators and systematic function require independent and redundant protection hardware or mechanical interlocks. It is important that when power is cycled, the user waits at least 10 seconds before restoring power. Switching the power on and off quickly can damage the unit. The interface is connected to remote equipment using a RS232C or RS-485 cable. The connector that is used is a RJ45-8 pin type. The using a long PLC cable to connect the unit, a difference of electric potential can be observed between the cable and the ground, even when connected to a ground. The serial port on the HMI-STU-855 is not isolated. The signal ground and frame ground terminals are connected inside the unit. When setting up the RS-485 communication, the cable diagram for some equipment may need polarization on the terminal side. This terminal does not need any special setting because it can handle polarization automatically.

MRO Electric and Supply Company stocks many Modicon Magelis HMIs and panels, including the HMI-STU-855. For for information or to request a quote, please email sales@mroelectric.com or call 800-691-8511.

HMI-STU-855
HMI-STU-855

TSX PLCs – Compact, Flexible, Cost-Effective

TSX PLCs
TSX Nano PLCs are easy to set up and have numerous built in functions, such as memory for storing programs, battery-backed RAM, and real-time clocks for modules with 16 and 24 I/O’s. They can be installed easily on a mounting rail or base plate in the vertical or horizontal position. TSX PLCs are programmed in lists of instructions using the FTX 117 programming terminal, in Ladder or Instruction list language using software on an FT 2000, FTX 517 terminal or PC compatible. They can be used to augment extendable TSX PLCs using a single extension per base. Depending on the model they have

16 I/O : 9 inputs + 7 outputs
24 I/O : 14 inputs +10 outputs.

The following types of inputs and outputs are used:

Inputs : 24 Volts
Outputs : Relay outputs for models with ~ 100… 240 Volt power supply, transistor outputs with positive logic for models with 24 Volt power supply.

I/O Extension

Each TSX Nano base PLC can be extended using an I/O extension. This extension is created by one of the PLCs with 10, 16, or 24 i/o. The function of each PLC is defined by the position of the coding selector switch:
Position 0 : base PLC
Position 1 : I/O extension

Peer PLCs

Up to 3 peer TSX PLCs, communicating via common words, can be connected to the base PLC. In this case, only the base PLC can receieve an I/O extension. The function of each PLC is defined by the position of the coding selector switch. I/O addressing of peer PLCs is identical to that of the base TSX PLC. The extension link cable between the base PLC and PLC extensions is shielded, twisted pair  and is no more than 200 meters long.  Each PLC has 2 reserved (IW) and 2 reserved (QW) words for exchanging data between PLCs. These exchange words are updated automatically. For each PLC, the user program is only able to write to the 2 %QW output words and read the 2 %IW input words.

MRO has many Modicon PLCs available. For more information, please email sales@mroelectric.com or call 1-800-691-8511.

Human Machine Interface (HMI) Retrofitting

At MRO Electric and Supply, we are experts at retrofitting older HMIs with a new interface that is clean, modernized, and still works with your system.

Take this older Fanuc HMI as an example. The old CRT display has begun to fade out, making its use inefficient and none user-friendly. Old CRT screens are also prone to overheating, and they take up a lot of much needed space.

Fanuc HMI
Fanuc HMI Pre-Retrofit

A new LCD retrofitted screen can give you more accessibility, brighter displays, and user-friendly colors. MRO Electric can quickly update your FANUC Displays and HMIs at a fraction of the cost of replacing your whole HMI. You also don’t have to rewrite your programming, or waste time and resources replacing your whole system.

Fanuc HMI next to LCD Retrofit
Fanuc HMI next to its LCD Retrofit

Below is a fully retrofitted Fanuc HMI with an LCD monitor. This lighter, energy-efficient replacement adds years of life and service to existing legacy equipment, and eliminates potential future downtime. In addition, all of our HMI repairs come standard with a 12 month warranty.

Newly Retrofitted Fanuc HMI
Newly Retrofitted Fanuc HMI

Get in touch with us today to learn more about this cost effective solution for your HMIs. You can request a quote by calling 1-800-691-8511 or by emailing sales@mroelectric.com.

140CPU43412A Error Codes and Hot Standby

Our previous blog post on the 140CPU43412A describes the 140CPU43412A Configuration and Setup. 

140CPU43412A Hot Standby

You cannot create a Quantum Hot Standby configuration running one 140CPU53414A PLC with Unity firmware and one with NxT firmware. When using an NxT configuration in hot standby, both PLCs must have NxT firmware. When using a Unity Quantum hot standby configuration, only specific hot standby controllers can be used. The 140CPU43412A and 140CPU53414A PLCs are not supported in Unity Hot Standby configurations.

140CPU43412A Error Codes

The following are the error codes for the 140CPU43412A:

140CPU43412A Error Codes
140CPU43412A Error Codes

140CPU43412A Error Codes
140CPU43412A Error Codes

140CPU43412A Error Codes
140CPU43412A Error Codes

For ordering info or for a 140CPU43412A price quote you can call 1-800-691-8511 or email sales@mroelectric.com.

140CPU43412A Firmware Part II

Phase 1 of firmware restoration is described in our previous blog post on the 140CPU43412A firmware.

140CPU43412A Firmware Part II

Restoring a 140CPU43412U (Unity) to 140CPU43412A (Concept):

Phase 2

During the download:

• Do not power OFF the PLC

• Do not power OFF the PC

• Do not disconnect the cable

• Do not shut down OS loader

Any loss of communication during the update procedure can cause severe damage to the CPU or NOE module. Failure to follow these instructions can result in injury or equipment damage.

Reset the PLC

Once the download of the intermediate binary file has completed, the PLC has to be initialized. This task can be performed by one of the two following actions:  Reset the PLC by pushing on the Restart button located on the CPU (for more information, refer to the PLC technical documentation).  Power OFF then ON the PLC. Once the PLC has restarted, go to Phase 3: download the final Concept OS.

Phase 3

Presentation

The final binary file “q5rv135E.bin ” (140CPU34312 in our example) has to be downloaded. For that, follow the same procedure as the one described in the Phase 1.

Checking Version (optional)

If needed, you can check the new CPU version. For that  Open the OS loader tool.  Select the communication protocol.  Click on “Connect.” Then Click on “Properties.”

For ordering info or for a 140CPU43412A price quote you can call 1-800-691-8511 or email sales@mroelectric.com.

140CPU43412A
140CPU43412A FIrmware