For few days I am working on proview. I found It is world first open source process control system. But as per my thinking it is not fully open source as because of IO cards. To make a real process control solution with proview everybody has to purchase IO cards & control module. I know there is a Arduino based open source IO in proview but frankly say the same can be used only for educational purpose not real process control. It has very less number of IO support, analog input is only 10 bit resolution and analog O/P is 8bit voltage mode not constant current mode. In real process plant analog O/P is use as 4 to 20 ma constant current loop.

So I started to build arduino based IO which can support 64DI, 64DO, 64AI (16 bit bipolar) , 64AO 12bits 0 to 24 ma constant current (sink). My design almost completed but during testing I faced some serious problem on proview.

First problem is related with the FTDI chip serial driver. I used FT232RL with vertual serial port driver comes with ubuntu10.04. After power on proview can not configure arduino IO as long as a single character is not send to arduino through arduino IDE serial port monitor. Please go through the following forum for details.
www.proview.se/v2/index.php/forum/4-prov...rduino-io-on-proview

Second problem is the method of arduino IO handled by proview is very poor. Only at startup proview tries to configure arduino IO if it fails there is no other way excepy restart proview because there is no way to send send configuration request farther.
I mean that Arduino IO is not hot swap able, which is very essential for process plant.

See, for example in a plant 1000 IO are there and all are distributed with 4 arduino IO controller. (Note that it is modified arduino IO). The process station has PCI based 4 port RS232 port and Arduino controller are connected with this port (tty10,tty11,tty12,tty13) through MAX232 chip (not USB to serial). Now out of 4 one arduino controller got faulty and the plant manager has decided to start the plant disabling IO connected with that faulty Arduino IO controller. The proview ahs started with configuration error on tty13 port. After some days the faulty controller has been replaced by a new one but still it is not as proview is not configuration it. Now my question how to configuration it? Restart proview? It is not possible because plant shutdown can be done only on the schedule date. So what to do?

My suggestion is, after power up arduino IO controller will send a configuration request to proview and then proview will send the configuration packet after that it will starts working. Plrease note that with this technique no shutdown is required.

For this feature I can do arduino side code modification but proview side code modification also required.

So I request proview team to accept my idea and do the needful and give me a chance to contribute for this open source.

I would be happy if the person who build arduino for proview come forward and collaborate with me to make this high capacity arduino IO.

Thanks & regards
Jags

Hi Jags,

Looks like an interesting project. What are your plans ? Are you going to manufacture and sell the board ?

The proview-arduino communication is of type master-slave where Proview sends a request and arduino answers, and I would like to keep it that way. So I suggest that Proview sends a connect request, for example every 5th second if the connection is lost or not yet established. You also have to consider the terminal driver that, if you use an USB connection, will remove the tty device if the device is unplugged, and create a new device that has to be opened by Proview when the cable is plugged in again. There should also be a choice of what to do if the connection is lost. In most of our plants, it's not such a good idea to continue the production if parts of the IO are lost. Usually the choice is to stop IO or reset the inputs.

/Claes

Hi Claes,
Thanks to show interest about my project.

Yes I want to manufacture and sell the board but it will be very lower in cost. I don't want to make lot of money from this, as well as the same project may be open source on request. I mean if some body want to get the idea I will send him all information how to build it.

However if you (proview team) want something different or any objection regarding my thought, you are requested to let me know. I always respect proview team.

I don't have any problem with this master slave approach if Proview sends a connect request, for example every 5th second what you have said. To avoid remove of tty device I prefer PCI to serial port so that no one can remove it. For USB to serial port what you have said I agree with you.

Regarding running plants with partial IO(s) is depends on type of plant. The plant for which I am working has five reactors and all are produce same material. Say each reactor has there own IO controller (arduino) and they are connected with five tty port. For any instant if one IO controller is faulty, in such situation other four reactor can be run. I think you understand what I mean.

For this new master-slave approach is it required to release new build of proview or in this current build I can configure it?

Thanks & regards
jags

Hi Jags

I sugest to use an arduino ethernet or extend the arduino with an ethernet shield.
There exist an modbusmq lib for arduino, so you can use the arduino as a modbus TCP Server.

Then you don't have problems with USB connection that have each time a different name, you don't have to buy PCI serial cards for your computer.

Modbus TCP is already implemented to proview as a kind of standard connection.

Ethernet is a standard and flexible way of communication.

I have already an arduino ethernet but forgot to order a FTDI USB converter to program it.

Let's work together to develop a nice open source arduino Modbus TCP Server.

With kind regards


Tim

Hi Tim

Actually my project almost finish, so no question to stop. However I am ready to work with you for arduino modbus tcp IO.
I don't have ardino TCP/IP board. Now you can build and test modbus TCP stack after that my IO module stack can be merged.

regards
jags

Hi Jags

Can you post what you already have?

With kind regards


Tim