design PLC with FPGA

I want to design a PLC using a FPGA but I don't know what I must do. Can anybody help me ?

I want to design and build a car using a metal lathe, a hammer and a saw.

Could someone tell me how to do that?

I don't know FPGA but google had this, Good luck.

http://www.xilinx.com/

That is an improper analogy. Intel processors are used in many devices, FPGA being one of them. A regular here builds motion controllers that use FPGA.

Look at Intel's site for resources etc: http://www.intel.com/

Building a PLC is not a cheap endeavor so why reinvent the wheel? Because you can.

I would also look at robotics: http://www.robotics.com/

What is FPGA

OK I am new so,,,,,

What does FPGA stand for??



Dan Bentler

http://www.webopedia.com/




Short for Field-Programmable Gate Array, a type of logic chip that can be programmed. An FPGA is similar to a PLD, but whereas PLDs are generally limited to hundreds of gates, FPGAs support thousands of gates. They are especially popular for prototyping integrated circuit designs. Once the design is set, hardwired chips are produced for faster performance

rsdoran said:

That is an improper analogy. Intel processors are used in many devices, FPGA being one of them. A regular here builds motion controllers that use FPGA.

Click to expand...

Building a PLC is not a cheap endeavor so why reinvent the wheel? Because you can.

Click to expand...

I'm not saying that it's impossible. It's just above the level of complexity and work required of just about anyone that isn't running a lab at Rockwell or Siemens.

Designing for an FPGA is like designing for actual silicon. You generally write up your logic in a high level HDL (VHDL or Verilog).

So, first you're going to have to figure out how you want your PLC to work internally (data files or tag based (a-la ControlLogix) memory, your entire instruction set, and how to implement complex instructions (PID for one).

Then you have to determine how to parse a user mode program (are you going to design a RLL interpreter?)

Next, you have to account for I/O

Communications are also a necessary component. Your PLC doesn't necessarily have to be network enabled, but a user has to be able to at least connect to it to download a program.

Then there are about a hundred other things that I've glossed over that make a PLC a PLC and a useful thing to have (ie. online editing)


In summary, it's one thing to implement a custom motion controller using an FPGA and quite another to try to roll your own entire PLC. A custom motion controller only requires a few specific commands as input, and the same for output (although the intervining logic can be about as complex as need be)

bambang said:

I want to design a PLC using a FPGA but I don't know what I must do. Can anybody help me ?

Click to expand...

I could, but won't. Bambang has provide no definition of what he wants to do and I won't play 20,000 questions trying to find out. If you have to ask then you don't know enough to even begin.

rsdoran said:

That is an improper analogy. Intel processors are used in many devices, FPGA being one of them. A regular here builds motion controllers that use FPGA.

Click to expand...

What's this? Xilinx is a good example of a FPGA. Visit the link above to find out more. We use Xilinx FPGAs in our motion controller designs. Rockwell uses Altera FPGAs in their motion controller designs. In both cases the FPGA handles the I/O. For instance, the high speed encoder counters and latches are all done using FPGAs for reasons that have been made obvious so many times on this forum.
jimbo3123 is right about writing the code in VHDL or Verilog. Putting a PID in FPGA would allow one to have PID update loops in the nanaseconds. These speed are not required in the real world so usually a DSP handles the PID.
FPGAs make great glue chips and are good for handling I/O very quickly.
Some FPGA are so big that one can even program a processor into the FPGA. THen one can add Ethernet and USB I/O or other devices. This allows one to mix and match features to perfect match the application.
Finally, you can't program FPGAs on-the-fly yet like you can program PLCs. This is one of the biggest advantages PLCs have.

Another example of an FPGA device is the Siemens FM352-5 High Speed Boolean processor. This is a 12 path parallel processor and has a cycle time of 1 micro-Second. It offers timing of output pulses down to 10 micro-Seconds.

The "Debug" version of my program, which uses 99% of the available FPGA memory uses 3600 Bytes in the CPU. FB programming is compulsory for the FM, so I'm not sure how many lines of STL/IL that would be equivalent to.

...

Buy a nice piece of equipment of Z-World... Cheap and a lot faster

http://www.zworld.com

I understand, FPGA are programmed by logic gates standards. Combinacional circuit.
The complex part is the one development parse (to compiler) to
translate the languages
I do not see because to affirm, to be inviable CPU FPGA for PLC. Because accurately?
This implementation, possible one equipament is upgrade only software , add "news set instrutions".
Not change "hardware" for more powerfull. Brands not supply this advantage for market?!

FPGA are used in products of control of power plants, where events of microsecond are captured.

I thought it was Flat Pin Grid Array

Drewcrew6

Bambang, with all due respect, Peter is right. Designing a PLC is a major undertaking. To me PLC means a general purpose controller with the ability to sense the status of external electrical sensors and actuate external electrical devices. It is generally programmed for specific applications and can be re-programmed readily. A PLC usually has a graphical programming language that emulates hardwired relay logic for at least some of it's functions.

If you are creating a specific purpose controller based on a FPGA you have a shot at completing the project. If you want a true general purpose PLC you are probably in over your head, or else incredibly gifted.

Wow... here's a blast-from-the-past...

http://www.plcs.net/cgibin/dcforum/dcboard.cgi?az=printer_format&om=2072&forum=DCForumID1