shaunakm
Hi,

I was trying to implement the Concept Hardware on my setup, but I was unable to find any tutorials/ Getting Started guides regarding the same. It will be of great help if you share any links for the same.

Thanks and Regards.
Quote 0 0
thiagoralves
The concept hardware is old and is not supported anymore with the current OpenPLC software base. It is there just as a hardware guide if you're looking to develop your own I/O boards. If you want to build a PLC from the hardware level, I suggest you to start with a Linux SBC such as RaspberryPi, OrangePi, BeagleBoard, NanoPi, etc... Then you create the I/O interfaces according to the input and output board schematics for the concept hardware.
Quote 0 0
tonymendo1988
Ok Thanks. Is there a old version of the software base that was compatible with the concept hardware? Looking at the schematics it seems like the concept hardware was using Modbus RTU to communicate between the different cards and CPU. Did you find this to be too slow to respond ? I'm trying to develop a similar modular PLC for hobby of mine.

thanks
Quote 0 0
tonymendo1988

I had another question for the Input card whats the intended input voltage range? Was wondering why you had a 2W 4.7K resistor in series?

thanks

Quote 0 0
thiagoralves
You can download the old ladder editor here: https://drive.google.com/file/d/0BwyThwktWLAlQjRkMXVrVVRsLUk/edit?usp=sharing

Just keep in mind that this is completely different that what you currently have with PLCOpenEditor. The interface is much simpler, but it is still ladder logic! This editor will also let you upload code to a stand-alone arduino.

About the input card, the resistor was to limit the current on the internal optocoupler LED. The input voltage is (if I'm not mistaken) 5-40V
Quote 0 0
shaunakm
Hi,

Thanks for your quick replies. That is really a great help.
Quote 0 0
tonymendo1988

Thanks for the quick response Thiago. For the bus that connects the input and output cards. I'm assuming your just using the Modbus RTU protocol. Is this correct? Do you know of any other open standards that are more modern to PLCs that I can implement?

thanks

Quote 0 0
thiagoralves
I'm not using Modbus for that. I created my own protocol called OPLC protocol to communicate with the boards. I wouldn't recommend you to use it because it's not a very good protocol... [rolleyes] It doesn't have any kind of integrity checking (CRC) and requires a lot of bandwidth because each message sent by a client has to be requested by the master.

I've been thinking about a new protocol that is much better than this. I'm planning to use it on my next version of the OpenPLC hardware (yes, I'm finally designing a new hardware board that will be totally compatible with the current software and I'm planning to sell it on the website once its ready). It will be light, with a small overhead, full duplex, will have spontaneous messages from clients and will only send the data that has changed to decrease bandwidth consumption.
Quote 0 0