Raspberry Pi Forums

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

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 Some is a bit out of date.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

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.

You can add 4-20mA inputs by getting an i2c interface board if you need to.

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

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