DennisIPT
Posts: 1
Joined: Thu May 08, 2014 7:40 pm

Input/Outputs - Config

Thu May 08, 2014 9:14 pm

Hi all,
I have made a lot of money out of PLC Programming - but that was years ago and the mystery has gone.
However, I saw the Pi guide in Asda a few hours ago and bought it, now I want to know more.
I'm an Electrical Engineer but I teach Electrical/Electronics etc.
So, what is the I/O config of a model A or B? Digital I/P - what voltage 5V, 12V, 24V?
Can it take 4-20mA?
Can it accept a fieldbus - eg Profibus?
Can it accept Ethernet? RJ45 socket etc?
What about outputs? Do we have 4-20mA O/P?
Do we have digital O/P - if so what voltage and what current? It's so small it looks like we need a more industrial front end for I/O.
I'm in Liverpool - do we have any "knowledge" centres in Liverpool?
If there is a link to an I/O layout for the Pi pls just refer me to it - thanks

Dennis

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rpdom
Posts: 17173
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Input/Outputs - Config

Fri May 09, 2014 4:48 am

Hi,

I/Os are 3.3V logic. Outputs can handle up to 16mA with a total of 50mA on all outputs at any time.

RJ45 Ethernet is included as standard on the Model B Pi, along with two USB2.0 ports. Model A has only one USB2.0 and no RJ45.

There is much info out there on the Pi. Some is a bit out of date. These links are useful for a start

http://www.raspberrypi.org/help/what-is-a-raspberry-pi/

http://www.raspberrypi.org/documentation/

http://elinux.org/RPi_Low-level_peripherals

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Richard-TX
Posts: 1549
Joined: Tue May 28, 2013 3:24 pm
Location: North Texas

Re: Input/Outputs - Config

Fri May 09, 2014 6:53 am

There are no 4-20 ma (current loop) interfaces on the Rpi.

Profibus is not native.

As far as industrial controls go, you will have to add your own except for ethernet.
Richard
Doing Unix since 1985.
The 9-25-2013 image of Wheezy can be found at:
http://downloads.raspberrypi.org/raspbian/images/raspbian-2013-09-27/2013-09-25-wheezy-raspbian.zip

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: Input/Outputs - Config

Fri May 09, 2014 7:15 am

You can add 4-20mA inputs by getting an i2c interface board if you need to.
Doug.
Building Management Systems Engineer.

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Burngate
Posts: 6302
Joined: Thu Sep 29, 2011 4:34 pm
Location: Berkshire UK Tralfamadore
Contact: Website

Re: Input/Outputs - Config

Fri May 09, 2014 10:39 am

DennisIPT wrote:I'm in Liverpool - do we have any "knowledge" centres in Liverpool?
Have a look at http://rastrack.co.uk/ to see some Pi-owners
Also look at http://raspberryjam.org.uk/ for anything local. Though nothing's coming up on there round your way.

Hackerspace could be worth looking at - I've just followed a link from there, through to http://doesliverpool.com/ which mentions Maker Day tomorrow

boyoh
Posts: 1468
Joined: Fri Nov 23, 2012 3:30 pm
Location: Selby. North Yorkshire .UK

Re: Input/Outputs - Config

Sat May 10, 2014 10:57 pm

DennisIPT wrote:Hi all,
I have made a lot of money out of PLC Programming - but that was years ago and the mystery has gone.
However, I saw the Pi guide in Asda a few hours ago and bought it, now I want to know more.
I'm an Electrical Engineer but I teach Electrical/Electronics etc.
So, what is the I/O config of a model A or B? Digital I/P - what voltage 5V, 12V, 24V?
Can it take 4-20mA?
Can it accept a fieldbus - eg Profibus?
Can it accept Ethernet? RJ45 socket etc?
What about outputs? Do we have 4-20mA O/P?
Do we have digital O/P - if so what voltage and what current? It's so small it looks like we need a more industrial front end for I/O.
I'm in Liverpool - do we have any "knowledge" centres in Liverpool?
If there is a link to an I/O layout for the Pi pls just refer me to it - thanks

Dennis
All the information you want on the Raspberry is all on
The Internet The Raspberry Pi User Guide by
Eben Upton is a good starting Point. Being
A electronics engineer you will have no problem
Digesting it. The 4 / 20ma and 0/10v signals
Will have to be converted to digital signals for
The Pi to in/put. All analog signals will have
To be converted to digital
A little bit different to the PLC ladder diagram
And all the X & Ys
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

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