Keyboard to PLC as data input

tlona · May 16, 2007

Has anyone ever connect a keyboard directly to a PLC for data entry? I have an application where I want to use an industrial keyboard to directly input data to my Allen-Bradley microloc 1100 PLC. I do not want to use a Panelview becausde I do not think the buttons will last very long in my application. Thank-you

OkiePC · May 16, 2007

I know a guy (who is now retired) who designed and built converter circuits to allow the use of a modern PS/2 keyboard in place of old AT keyboards of some proprietary systems which could not be easily upgraded. He also designed interfaces to replace some specialized serial keyboards with PS/2 keyboards.

So, it probably can be done with extensive research and development...nothing is impossible eh?

You may be able to find a special keyboard that puts out a serial data stream that can be read by a PLC.

I would argue that a PanelView is going to be as rugged than an industrial keyboard, though, also, you will need a way to display what is being typed. So you may as well just buy an industrial PC and use its serial interface to connect to the PLC along with some HMI software too.

http://www.laversab.com/ruggedized_computers.html

http://www.stealthcomputer.com/portables_notebook.htm

brucechase · May 16, 2007

If you are interested in a different kind of keyboard, then look at this one. It is only USB with PS2 adapter so I have no idea on how to get the data into the plc directly, but for an industrial keyboard, it might be worth looking at. I've tried this with mixed results. The first time using it, the operators took it as a challenge to destroy - which they promptly did after a couple of weeks. I also have one in service for 3-4 years now. I just thought they were neat.

http://www.grandtec.com/vik.htm

theDave2 · May 16, 2007

http://www.vetra.com/412text.htmlGive a call to them. They have been around quite some time. Might have something.

Connecting a PS/2 (or AT) IBM keyboard to a PLC is darn near impossible. It's a 2 wire bidirectional clock/data protocol, with timing far faster than a PLC can handle.

So you have only a couple of choices: serial keyboard (still around, google it: http://www.accesskeyboards.co.uk/AT2SER.htm), a switch / PB bank wired to the above or do it directly via I/O.

tlona · May 17, 2007

Thank-you all for the feedback. These are some good suggections. It is greatly appreciated

parky · May 17, 2007

The only real way is to use one of the membrane type with matrix output (row/col), used one of these some time ago, you need to connect rows & cols to an input card, most have an extra line for key pressed, you could then on key pressed, input going high look at rows/cols & decode the binary data, you would also probably need to build interfaces for the signals as most keyboards are 5V

The alternative is to use an old siemens WF470 keyboard (if you can get one), these were used on the old S5 WF470 graphics, the keyboard was connected to an ordinary 16 way in 16 way out 24v I/O card the outputs were used for the led's.

Jiri Toman · May 17, 2007

I don't see how you can use just the keyboard for the data entry. You need to see what data is inside the PLC, you can't be entering in the data blind?? A touch screen HMI or an HMI with integrated membrane switches / keys in the lexan overlay will in fact last longer than a regular keyboard.
Secondly as you enter the data, the PLC needs to understand where the data is going! How will you do that with just a keyboard??
I don't think that you have given this much thought.

TimothyMoulder · May 17, 2007

This came up at the Unitronics user's forum recently, and this looked like a pretty good idea. It gets power from the serial port (12VDC), so you might have to do some creative wiring to juice the thing.

Am I wrong? I thought the 1100 was ethernet-only?

http://l3shop.com/data/kb232.pdf

Hakutsuru · May 17, 2007

Sure you could enter data blind. Just not 100% sure why you want to. But, the 2 ways I can think of to do it are to either find a keyboard that can buffer the data, and type all the proper df1 commands in (would be interesting to see if/how that worked) or get an ascii keyboard like timothy moulder has there and set the port up as ascii. I've never actually done an ascii reader in a PLC, so thats another solution I'd be interested in seeing how it worked.

Oh yeah, and the 1100 does has a serial port that can handle ascii, theoretically.

-jeff

Gil47 · May 18, 2007

tlona said:
Has anyone ever connect a keyboard directly to a PLC for data entry? I have an application where I want to use an industrial keyboard to directly input data to my Allen-Bradley microloc 1100 PLC. I do not want to use a Panelview becausde I do not think the buttons will last very long in my application. Thank-you

I know this is not directly answering your question.
I had a need for a keyboard in an environment that at times has some chlorine gas and I used a panel view plus sealed in a gas proof box and took a USB mouse out of this box to be sacrificial
From that I can call up the keyboard and do data entry by mouse clicks
One year later still the same mouse

parky · May 18, 2007

I agree that an HMI is the best solution however if a keyboard is a must then all you need to do is write a block that will handle the binary bits the way you want them (a lookup table is best).

Well siemens did it for wf470 & it worked well, the keyboard was very reliable although the cost of such a beast + I/O card would be almost as much as a simple HMI.

Montero99 · Oct 31, 2017

I don't think it's possible! and it depends on the keyboard your gonna use

RobertB · Oct 31, 2017

If you can get serial comms, wouldn't data come in the ASCII format with known values for each character?

RobertB · Oct 31, 2017

Hit the enter too soon.
Also, I agree, the PLC would have to be programmed ahead of time to know where such data goes. I agree, an HMI is built for this already, and you can get used ones on Ebay much cheaper than you might think.

Oceansoul · Oct 31, 2017

Im sure the OP found a solution to this 10 years ago!
Was it really necessary to join this forum to just post in this ancient thread?

Keyboard to PLC as data input

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