Basic steps to design a PLC

Hey guys,
Recently, I've searched a lot on the subject of design steps in PLC hardware and software. But I couldn't find anything useful. In fact, I want to write a paper on the process of making a PLC hardware and software. Which steps should be taken for making a brand new PLC that can work properly in industry.
Can anybody introduce some reference on this issue?
Thanks

Your earlier posts contain a lot of Siemens Step 5 Questions.
then follow on with the Fanuc PLc's
the Siemen Step 5 has been superceded for many many years.
The Fanuc is not so widely used.
If you can purchase PLC's than that is the way to go.
I am not sure what market access you have.
But to redesign the wheel is the wrong way to go.
The PLC eventuated from TTL PCB's And EPROM ram Chips.

What are ou trying to achive

iant said:

Your earlier posts contain a lot of Siemens Step 5 Questions.
then follow on with the Fanuc PLc's
the Siemen Step 5 has been superceded for many many years.
The Fanuc is not so widely used.
If you can purchase PLC's than that is the way to go.
I am not sure what market access you have.
But to redesign the wheel is the wrong way to go.
The PLC eventuated from TTL PCB's And EPROM ram Chips.

What are ou trying to achive

Click to expand...

I know to redesign the wheel is the wrong way, but this problem is something else and I just want to write something about PLC in details and designing stage of it, may be they want to design the wheel again , anyway thank you for the post and if you know any references on this issue, I'll appreciate for introducing to me.

There is no way on earth that you will be able to design a PLC system for cheaper than most of the makes and models available on the market today.

It’s a highly competitive industry. All PLC vendors today is one form or another allow for interfacing between different systems. All the various communication bus systems available on its own will make your attempt futile. You will have to adhere to international standards as specified by IEEE and other governing bodies. Who will maintain your design? Do R&D testing and have it certified for industrial use?

Unless you won the Euro Lotto and have Billions of Euro’s and you don’t know what to do with your money, it’s really pointless.

Start with one system and try to understand what they offer and how it differs from the rest.

Rockwell Automation (Allan Bradley)
SIEMENS
ABB

To name a few of the big guns.

Each one of these suppliers have PLC’s ranging from micro systems to full blown DCS systems. <10 I/O to over 250,000 I/O points.

Identify your needs and use that as a basis to choose a vendor that will best suite your requirements.

I am of the opinion that if you don't know in detail how PLCs work, then how can you write something for someone else to use as a design tool.

I don't see how you will be able to get enough information (either from here or google) to specify in detail the steps to design and build the hardware and the steps to design and write the complementary software.

As asked, what are you trying to do? Write a thesis paper? Present at a conference? Write a book?

Iman said:

Hey guys,
Recently, I've searched a lot on the subject of design steps in PLC hardware and software. But I couldn't find anything useful. In fact, I want to write a paper on the process of making a PLC hardware and software. Which steps should be taken for making a brand new PLC that can work properly in industry.
Can anybody introduce some reference on this issue?
Thanks

Click to expand...

How many years are you allowing for this project?

the main push for an industry standard is Europe
do a search for CODESYS
this will become the indstrial over the next twenty years.
I say twenty because by then the new stuff today will be reffered to as OLD CLUNKERS

PLC software is a compiled list of blocks of Machine code (or C) and they are all tied together.
good examples are codesys, flowcode, arduino