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Topic: Arduino interface with Industrial Components (updating) (Read 913 times) previous topic - next topic

autumnzhang

Jan 23, 2014, 04:30 pm Last Edit: Feb 11, 2014, 04:15 pm by autumnzhang Reason: 1
[Please see thread 3 for project update! --- currently the focus of the project is to get laptop and arduino to communicate with each other --- any recommendation for programs? Processing? TeraTerm? better suggestions?]
Hello everybody,

I want to build a pneumatic control system with Arduino processor. But I have little experience in electrical circuit, so I'm searching help on how to design the system architecture and peripheral electronics. I'll try to describe the system I want as best as I can, but I may use some not-so-precise words because I don't know better.Please help me realize my faults and ask for any more information you need. I greatly appreciate any suggestions and hints you may have to offer.

The system will have 4 pressure sensors as inputs, each giving a 4...20mA analogue output. The system need to control 3 solenoid valves and 1 electrical actuated ball valve (just on and off). The system should be powered by 24VDC battery. A very crude system schematic and the components are shown as figures below. The specification for the sensors and valves can be found in the attachment.  I hope the system can have a touch screen as user interface, so that the pressure sensor outputs will be displayed and the command to open/close valves can be sent via the screen.

I need general help on how I should approach this problem. More specifically:
1)  what Arduino board should I use?
2) how do I build a power distribution box? Can I buy one somewhere?
3) I think each valve will draw about 0.5A current, how should I build such a relay box? Can I buy one somewhere?
4) any recommendations on the touch screen and library to program the user interface?

Or anything you can think of relating to the problem...

Thank you all for reading the post!! Any hint or suggestion could help me get a start on the project is great appreciated.

Sincerely,

Autumn



System Schematic:


Pressure sensor: Operating voltage  8.5...36DC,  output 4..20mA analogue

Solenoid valve: Operating voltage 1.8 to 256VDC, nominal power 9.5watts

Eletrical actuated valve: see attachement




Graynomad

There's a lot going on there, maybe that scared everyone off. I'll see if we can get the ball rolling.

Touch screen - plenty around, I've used some from 4D Systems, they will get their power from the Arduino so no need for extra PSU for them. These displays use a serial port.

Fieldbus - What do you have in mind here, a "bus" is usually just 2-3 wires that run to all devices on the network, you have drawn something that appears to have one-to-one links to several devices.

Which Arduino - It looks like you will need 2-3 serial ports, so on that basis I would say get a Mega or Due.

4...20mA analogue output -  Are you actually interested in the linear value or is a simple on/off based on a set point ok?

how should I build such a relay box? Can I buy one somewhere? -  Yes there are 1000s of relay boards around.

how do I build a power distribution box? Can I buy one somewhere? - It's not clear yet that you will need one as such. Certainly you will need to step that down for the Arduino, but until the other stuff is nailed down a bit more no need to think to much about the power supply IMO.

Battery 24VDC - Remember the 24V is the "nominal" voltage, under charge they go to about 30V, it usually doesn't matter much but can effect some things.

Physical distribution - How far apart are all these gadgets, 3 feet means one approach, 300 yards needs a different approach.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

autumnzhang

Hi Rob,

Thank you so much for your reply!
I have some updates on the project as shown in the attach figure:


You mentioned you think I need 2-3 serial ports, but I don't quite understand why. My sensors output 4...20mA current and I found somewhere from the help forum a circuit that converts the current to about 0-5V for arduino analog input.

Another thing is that I want to use laptop to command the Arduino instead of touch screen now. So I definitely need one serial port for communication. I'm looking into using software called "Processing" to build a user interface on the laptop and receive and send info from and to the Arduino board via USB.

However, I haven't figured out how to send data from Processing to Arduino via serial port yet. Do anybody know if it's possible? Can you leave a link to a tutorial or something ?

Autumn

Riva


However, I haven't figured out how to send data from Processing to Arduino via serial port yet. Do anybody know if it's possible? Can you leave a link to a tutorial or something ?

Autumn

Here you will find example code for sending commands to arduino and reading/displaying data back from arduino. It's not very elegant as it is/was my first and only processing sketch.

autumnzhang


Here you will find example code for sending commands to arduino and reading/displaying data back from arduino. It's not very elegant as it is/was my first and only processing sketch.
[/quote]

Hi Riva,

Thank you for your reply!!!
However I'm not quite sure where I should find the code you mentioned? do you have an attachment somewhere I didnt see? >_< sorry im a newbie

Autumn

Riva


Thank you for your reply!!!
However I'm not quite sure where I should find the code you mentioned? do you have an attachment somewhere I didnt see? >_< sorry im a newbie

Sorry Autumn, I forgot to include link in my post  :smiley-red:
I have updated the post but here it is again.

Graynomad

Quote
2-3 serial ports, but I don't quite understand why.

Touch screen
Field bus
PC

That's 3 (depending on the touch screen used, hence I said 2-3). But you've changed the spec so it looks like you only need 1 now.

The latest diagram looks reasonable, 20mA through 220R will give you 4v4.

You will need transistors to drive those relays, unless they are included on the relay board.

_____
Rob

Rob Gray aka the GRAYnomad www.robgray.com

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