Hardware concept

Article#: 00067

Date: 2021-09-12

Author: Radim

How do we choose the right electrical and pneumatic components (PLC, HMI devices, converters, pneumatic valves, actuators, sensors and others)?
The overall hardware concept must be designed according to the requirements.

1. Functionality:
What functionality must the component essentially have?
Which additional functions would be nice to have?

2. Environment:
Do we need to consider some of these extremes of the environment in which the component will be installed and operated?
High temperature, low temperature, high pressure, low pressure, high altitude, explosive substances, sterile environment, high humidity, vibrations, dust, chemicals, radiation ...
What is the maximum allowable size of the component?

3. Performance:
What is the minimum and maximum parameter value we need?
E.g .: CPU speed, memory size, sampling rate, communication speed, resolution, energy consumption ...

4. Scalability / topology:
Can some machine parts work autonomously and independently on the others?
How is the machine powered?
Can some machine parts be switched off on purpose?
Do we want to carry out the machine test and commissioning part by part?
Will we use one central machine intelligence (one PLC) or several?
Will we use decentralized IOs?
Do we need to consider future expansion options?
Which communication media and which protocols are possible and which suit us?
How many nodes will we have? What is the maximum number of nodes of different technologies?
What communication speed do we need? What is the maximum communication speed of different technologies?
Which cable lengths do we need? What is the maximum cable length of different technologies?

5. Connectivity / interfaces / compatibility:
Which devices do we need to connect? Which interfaces will we need?
Do we need to install third party software?
How is the mutual compatibility of the devices?
Do we need to consider backward compatibility?

6. Safety:
Which safety functions must the devices offer?

7. Security:
Can we protect the source code from unauthorized access?
How can we prevent unauthorized access to the machine functions?
Can we give different user roles access to different functions?

8. Operation and signaling:
Do several operators have to operate the machine or view the machine data at the same time?
How and from where do the users operate the machine?
How and where do we inform users about the machine status?
Which signaling, visualization and operating devices will we use?
Do we need a fix mounted or mobile HMI?
How complicated and demanding will the visualization be?
How many pages with what content will the visualization have?
How big does the HMI display have to be?
What HMI hardware performance do we need to meet the requirements of the HMI application?

9. Support / quality / maintenance:
How well does the supplier support work?
How long will it be possible to buy the device or spare parts?
What are the license policies?
How robust are the devices?
Do the devices need regular maintenance?
Where can we buy spare parts?
How easily and cheaply can a defective part be replaced?

10. Ease of use:
How friendly is the development environment for a developer?
In which programming languages can the code be written?
Which diagnostic tools are available? How useful are they?
How easy is it to update a new program on the device?

11. Design:
How important is the design?
How much prestige look should the components have?

12. Price:
What does the device cost?

© Radim-Automation, 2020–2025. All rights reserved.
Sharing of this article is permitted with proper attribution (link to the original page).

Related previous articles:

• A good concept = Complete set of suitable solutions
• Are there also any disadvantages?
• Think critically!
• Design machines with a focus on user's abilities and needs
• Learn from your journey!
• Why do automation projects fail?
• Collect all the requirements and sort them!
• Who will operate?
• Functional and intuitive HMI
• Is the way really the goal?
• Do you really want to start with this?
• I can see what you can not see
• More than just start and stop
• Safety first!
• Do the right things and do them right!
• Define test scenarios and test cases continuously!
• Don't make it worse!
• Write a project diary!
• Keep the answers to the question "Why"
• Everything is difficult until it becomes easy
• Realize every good idea ASAP!
• Get and stay in the flow!
• Industrial evolution - Listen to your customers and follow new trends!
• Stay alert!
• Have an expert on hand!
• What does the customer need?
• Don't disappoint your customer!
• Ask questions!
• Request bottom-up input!
• Focus on target!
• Think on paper!
• Don't hide any problem!
• Keep it simple!
• Success is not a matter of coincidence
• Choose the right tool!
• Good communication is important
• Development is evolution
• Follow the vision!
• Don't neglect and don't skip any step!
• Transparency and reliability
• From an idea to a consistent system

Related next articles:

• Machine modularization
• Knowledge gained from a completed project is priceless
• Choice of programming language
• Visual modeling
• Safety relays versus safety PLC
• Software update
• Design considerations for effective HMIS
• Clear signals
• Talk to operators
• It doesn't work without sensors
• Event logger as the very first function implemented in the program
• Diagnostic tools
• My boss was a hero
• PLC network diagram
• Keep the documentation up to date throughout the project
• Dream of a platform-independent PLC program
• Keep everything you need together
• Hidden dangers during commissioning
• Choosing an HMI display
• The false illusion of rapid progress
• HMI layout and correct display size
• HMI layout design
• HMI navigation

Comment#: 00001

Date: 2021-09-13

User: Radim

We should choose the PLC to be sufficiently powerful and have enough memory. Definitely for a prototype! We need to focus on the concept and development of a suitable application and not stress when we find out during development that our PLC is too weak for our requirements and our application. When we have the application developed and we want to choose a PLC for a serial machine, we can start optimizing and saving if we see that the PLC has large reserves.

Comment#: 00002

Date: 2021-09-13

User: Radim

In addition to the hardware costs, the software costs must also be taken into account in the total project costs. The HW must therefore be selected taking into account easy software development, diagnosis and maintenance.

Comment#: 00003

Date: 2022-04-26

User: Radim

A new generation of machine should run for several years. During the lifetime of the machine, new requirements for additional functions may arise. We shouldn't deliver a PLC from the outset that is already very short on resources. The PLC must have resource reserves so that we still have the possibility to implement new functions.

Comment#: 00004

Date: 2022-05-30

User: Radim

"Where switch controls will be used determines the degree of environmental protection required.
Industrial, transportation, indoor/outdoor public access, and lifting/ moving environments are considerably more challenging, exposing switches to oil, solvents, chemicals, water, and dust. For these conditions, rugged oil- and water-tight switches are needed, and under certain hazardous conditions, explosion-proof enclosures as well."

- Technical Article - Key Components Enhance the HHMI (2014-06-17)
- https://eao.com/switzerland/de/downloads/

Comment#: 00005

Date: 2022-07-11

User: Radim

"Bus systems provide many advantages over hard wired connections, including easy addition of new functionality – typically through software – without adding or replacing hardware. Wiring is much simpler and more flexible with smaller cables and connectors allowing for more compact design, and easier hardware updating and relocation. Bus systems also allow for any combination of information from multiple different sources to control output devices."

"There are trade-offs, however. BUS systems are more complex when only a small number of inputs and outputs (I/O points) are required. Also, special tools and well-trained personnel are required to design and service a bus system."

- Technical Article - Key Components Enhance the HHMI (2014-06-17)
- https://eao.com/switzerland/de/downloads/

Comment#: 00006

Date: 2022-08-17

User: Radim

The delivery times for electronic material are currently extremely long (sometimes even longer than 1 year). Therefore, the first step seems to be to find the suppliers who can deliver the material on the desired date and in the required quantity, and only then select the material from suitable candidates according to the criteria in the article.

Comment#: 00007

Date: 2022-10-30

User: Radim

After we know the requirements for the functionality and safety of the machine, it is good to choose those electrical components that can be connected via one type of bus. This reduces the effort and costs for wiring components on the machine if, for example, the same bus can be used both for data transmission and for safety-related data.
What devices do we usually need to be connected to the bus? E.g. PLC, decentralized IOs, frequency converters, safety PLC and safety IOs.

Comment#: 00008

Date: 2022-11-15

User: Radim

"There is a need to test performance throughout the development cycle. If the lack of performance is only discovered in heavy traffic, that's a huge slip-up."
Translated from:
- Petr Paleta. Computer Press (2003). Co programátory ve škole neučí.

Comment#: 00009

Date: 2022-11-30

User: Radim

New problems occur in real operation that were not expected or experienced during development or test operation.
Then you are happy if you know the system / devices well, if you know how they work, how they are connected and controlled, etc. This know-how comes simply from working on the system, from solving smaller and larger problems...

Comment#: 00010

Date: 2022-11-30

User: Radim

During development, do not use other (preliminary) hardware than the one selected for production. You gain important experience with the hardware. You will find out whether the performance is sufficient and learn how to eliminate problems that arise during development. If the software development phase is carried out on the hardware designed for sharp operation, you will experience fewer unpleasant surprises after the machine is commissioned.

Comment#: 00011

Date: 2023-04-19

User: Radim

"Why does the bus system really matter?
Well, the importance of the bus technology is often underrated. Most people think that the controller is the core of the control architecture. But in fact, it's the bus that determines if you can make use of that controller performance or not. It's a bus technology that also determines what kind of components you can use especially if you use a technology that's only supported by a few, you end up with overpriced components because there's a small selection.
So the bus is the core the real core of the control architecture and it cannot be overrated in its importance."
- https://www.beckhoff.com/en-en/company/news/multimedia-hannover-messe-2023-day-2-beckhoff-live-interactive-april-18-2023.html
- Interview with Martin Rostan (05:25 - 06:24)

Comment#: 00012

Date: 2023-06-08

User: Radim

"Also check the onboard electronics for good EMI (electromagnetic interference) and surge withstanding capability, as well as to verify that the device's power consumption meets your budget. And make sure the connection ports are what you need in your application (Ethernet, serial, USB, other)."
- David Greenfield, Jeanne Schweder. AutomationWorld (2023). HMI & SCADA Amid the Digital Transformation.
- https://www.automationworld.com/control/article/33001916/hmi-scada-amid-the-digital-transformation

Comment#: 00013

Date: 2023-07-21

User: Radim

"The essential function of the PLC is to receive data from sensors or other field devices; make a decision on what to do with that information based on its programming instructions, for example, to open or close a valve based on fluid levels or direct a robot to pick up an object based on its presence in the work cell; and send the correct signal to the actuator (such as a valve or robot gripper) to perform the task."
- David Greenfield. AutomationWorld (2023). Peer-to-Peer FAQ: Controllers.
- https://www.automationworld.com/control/article/22724233/industrial-controller-technologies

Comment#: 00014

Date: 2023-09-11

User: Radim

Does it make sense to think about digitalization if we don't see any use case?

"If you don't see any practical use case or clear benefit for digitalization in your specific situation, it may not make sense to pursue it blindly. Digitalization should always align with your organization's goals and needs. Here are some considerations:

1. Assess Business Objectives: Start by identifying your organization's objectives and challenges. Digitalization should align with your strategic goals, whether it's improving efficiency, reaching new markets, enhancing customer experiences, or reducing costs.

2. Customer Demands: Consider whether your customers or clients expect or would benefit from digital solutions. If there's no demand for digital services, investing in them may not provide a return on investment.

3. Competitive Landscape: Analyze your competition. If your competitors are effectively utilizing digital technologies to gain a competitive advantage, it might be necessary to explore digitalization to stay relevant.

4. Cost-Benefit Analysis: Conduct a thorough cost-benefit analysis to determine if the potential benefits of digitalization outweigh the costs. If the investment doesn't offer a reasonable return, it might not be justified.

5. Resource Availability: Evaluate whether you have the necessary resources, including financial resources, technical expertise, and staff training, to implement and sustain digital solutions effectively.

6. Future Growth: Consider the scalability of your organization. Even if you don't currently see a clear use case for digitalization, it's essential to think about your organization's future growth and whether digital technologies could play a role in that growth.

7. Technology Trends: Stay informed about industry trends and emerging technologies. While there may not be an immediate use case, technological advancements could create new opportunities down the line.

8. Customer Feedback: Engage with your customers or stakeholders to gather feedback on their needs and preferences. They may provide insights that could uncover potential use cases for digitalization.

9. Pilot Projects: Instead of a full-scale digital transformation, consider starting with smaller pilot projects to test the waters and assess the feasibility and impact of digital solutions in a controlled environment.

10. Consult Experts: Seek advice from digital transformation consultants or experts in your industry. They can provide insights into potential use cases and help you determine if digitalization is appropriate for your organization.

In some cases, it may indeed be the case that digitalization doesn't make sense for your organization at a given time. However, it's essential to regularly revisit this assessment as technology and business landscapes evolve. What might not be relevant today could become essential in the future. Ultimately, the decision to pursue digitalization should be guided by a thorough understanding of your organization's unique needs and circumstances."

- https://chat.openai.com (Does it make sense to think about digitalization if we don't see any use case?)

Comment#: 00015

Date: 2024-01-07

User: Radim

"Some fieldbuses are only strong enough to accommodate about 250 nodes before needing to add another network, EtherCAT can have up to 65'535 nodes in one network."

- https://www.automationworld.com/communication/article/33010109/ethercat-plays-a-role-in-multiple-industries

Comment#: 00016

Date: 2024-02-14

User: Radim

Benefits and risks of software updates via remote access to customer machines

In today's agile world, quick and easy software updates are essential for maintaining technologies and systems. However, the transition from manual installation of updates to remote access raises an important discussion about the risks and benefits of this approach.

Technical feasibility and tools:
The technical aspect is not an obstacle. With today's concepts and tools, the application software can be updated on remote machines at the customer's premises.

Risks:
However, the main concerns relate to the risks associated with this procedure. There is a possibility that the installation of the new software version may cause unexpected problems that can have serious consequences. The machine may no longer be able to be started and may even no longer be accessible remotely. A specialist then has to travel to the customer. This can take up to several days and leads to expensive production downtime for the customer.

Benefits:
Conversely, remote software updates have many advantages. Customers do not have to wait for a technician to be present, which saves time and travel costs. In addition, the rapid availability of updates can improve overall customer satisfaction and increase efficiency.

Solution:
To minimize the risks associated with remote updates, clear rules and procedures must be established. These include thorough testing of updates prior to deployment, detailed data backup and recovery plans and adequate training of customer personnel.