An industrial control win for me

A customer called last week with a problem on their packaging line. one of the machines was running out of sync with the feed screw, and making a hell of a mess of the labels.

I took a look and found that the (poorly documented, of course) machine had an Allen-Bradley controller that was apparently misbehaving. After an hour of warmup where it would work perfectly, even though the "Product Present" prox sensor was inactive (and showed as such on the controller's LED strip ), it was still making "stick-a-label-on" output. This output went through a time-delay relay to produce a pulse that triggered an air solenoid that.. . well the details aren't really important.

Having ZERO information on the AB box or its programming, and having no acc ess to the programming cable or software, I took a different route. It was pretty obvious what the thing had to do to work properly - it involved look ing at three inputs, going through a state table and generating a timed pul se at the correct time.

I took a couple of quad OPTO-22 modules (one input,one output) and literall y electrical taped them together with an arduino board wired to the I's and O's with pigtails hanging off to connect to the existing controller. All t old, didn't take much more than an hour to get the stuff together.

I wired it in place, and the programming took about another hour to get the timings correct. And VOILA! the machine is fixed.

So now I'm thinking that maybe there's a product to be made - a board that holds a couple of Quad OPT-22 modules, a microcontroller, terminal blocks a nd enough power supply to run from 24VDC or 120/240VAC. Programmable in the language of your choice (mine is C, but whatever can run on an AVR).

As if I really need another project... I could bang this one out pretty qui ck. And I KNOW I could use a few now and then - it would have been good to have one sitting on the shelf ready to go last week.

Any thoughts?

Reply to
rangerssuck
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Perhaps you could make an opto-22 board that an Arduino either plugs into, like a large "Shield" or perhaps interfaces through a cable.

You could look up some of the micro PLC's that can be programmed by a keypad and have a small LCD screen, I figure an Arduino board would need some advantage over them to be competitive. Also it would be nice to have Arduino's capabilities such as the interrupts to read encoders and high precision timing of pulses in and out. With digital I/O, high speed counters, pulse in, pulse out, digital communications, analog in, PWM out, and so on, there would be a lot of potential.

RogerN

Reply to
RogerN

Sounds like you've reinvented the smart relay.

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Reply to
Ned Simmons

of the machines was running out of sync with the feed screw, and making a h ell of a mess of the labels.

had an Allen-Bradley controller that was apparently misbehaving. After an h our of warmup where it would work perfectly, even though the "Product Prese nt" prox sensor was inactive (and showed as such on the controller's LED st rip), it was still making "stick-a-label-on" output. This output went throu gh a time-delay relay to produce a pulse that triggered an air solenoid tha t... well the details aren't really important.

access to the programming cable or software, I took a different route. It w as pretty obvious what the thing had to do to work properly - it involved l ooking at three inputs, going through a state table and generating a timed pulse at the correct time.

ally electrical taped them together with an arduino board wired to the I's and O's with pigtails hanging off to connect to the existing controller. Al l told, didn't take much more than an hour to get the stuff together.

the timings correct. And VOILA! the machine is fixed.

at holds a couple of Quad OPT-22 modules, a microcontroller, terminal block s and enough power supply to run from 24VDC or 120/240VAC. Programmable in the language of your choice (mine is C, but whatever can run on an AVR).

quick. And I KNOW I could use a few now and then - it would have been good to have one sitting on the shelf ready to go last week.

Well not exactly, but maybe close enough. I think I'll pick one of these up to add to the arsenal.

Reply to
rangerssuck

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