ajit.nayak87
Dear all.
 i wanted to use Rasberry pi and openplc software to create own plc hardware for commercial purpose
I need few clarification before going further
Quote 0 0
thiagoralves
OpenPLC core is currently based on GPL-v3 license, but we are transitioning it to a more permissive license (Apache2). You can google the difference between these two, but basically you can sell a product with OpenPLC installed with either one of these licenses. The only thing you cannot do is charge for the OpenPLC software, close the source code on your product, or rebrand it and sell as something else. If you're selling a device, you must charge only for the hardware if it is based on OpenPLC. The software is free and open source.

OpenPLC runtime will run fine on any of the boards you sent on the links. Of course, the Pi Zero is the cheapest one available. You will have to design your own protection circuitry (optocouplers, isolation, etc) as the GPIO pins on these boards are very sensitive.

OpenPLC Editor is an offline editor, however, you can simulate your code inside it, force variables, contacts, etc.

You can use add-on slave devices normally with OpenPLC software. OpenPLC is software only, so there aren't any hardware licenses you should be worried about. If you're using plain Arduino boards, you might check what their license says about it.
Quote 0 0
ajit.nayak87
Thanks for clearing answers.how about power supply and Relay max current carrying capacity decided 
https://www.sferalabs.cc/iono-pi/
 
how to take care of analog reading where above people uses MCP3204  for better resolution.
how we decide max analog channel ?
analog input range from 0-30v 
because rasberry pi take 3.3v as analog input  need to build additional ckt to meet above requirement
Quote 0 0
thiagoralves
The Raspberry Pi does not have any analog inputs. You will have to use an I2C or SPI chip to have analog readings. Usually those chips will have an input voltage around 3.3V or 5V. You can use op-amps to convert it to 0-10V inputs or something else. I don't think 0-30V is a very common input. Usually on industry it is either 0-10V or 4-20mA.

Relay current and power supply will be up to you and your project. If it were me, I would actually use open collector mosfets on the output instead of relays. 
Quote 0 0
ajit.nayak87
IS there any limitation for writing code. codesys or Speedplc software they have some limitation while writing code on PLC system
Quote 0 0
thiagoralves
OpenPLC is free and open source. Codesys and Speedplc are not. That's why they have limitations. There aren't any imposed limitations on OpenPLC runtime.
Quote 0 0
ajit.nayak87
In order to use openplc and rasberry pi as plC what are item need to procure. weather SD card is needed?

if rasberry pi used as plc some people says after year it might corrupt the SD card.  how to make file system as read only. what type of card to be used for this application
Quote 0 0
thiagoralves
Read this article: https://hackaday.com/2016/08/03/single-board-revolution-preventing-flash-memory-corruption/
Quote 0 0
carlospetry77
Hello! I've a question. How many inputs via SPI can i add to openPLC? Can i add 100 digital inputs via SPI? Thanks!
Quote 0 0
thiagoralves
OpenPLC does not support SPI, unless you modify the raspberry pi driver to give support for that (which shouldn’t be too difficult). That being said, OpenPLC has support for 1024 I/O points (this is the size of the internal image tables). So, if you write the driver, and respecting the physical characteristics of the devices, you can have up to 1024 I/Os  
Quote 0 0
carlospetry77
OpenPLC does not support SPI, unless you modify the raspberry pi driver to give support for that (which shouldn’t be too difficult). That being said, OpenPLC has support for 1024 I/O points (this is the size of the internal image tables). So, if you write the driver, and respecting the physical characteristics of the devices, you can have up to 1024 I/Os  


Fine. So, who i can add 100 inputs to my raspberry throught openPLC? I2C?, Modbus? Canbus? Thanks!!
Quote 0 0
carlospetry77


Fine. So, who i can add 100 inputs to my raspberry throught openPLC? I2C?, Modbus? Canbus? Thanks!!


Sorry. I found the answer in "Slave devices". If you like, clear this messages. Thanks, have a nice day!
Quote 0 0