Calling all electronics pros!

Diddums · 27 Mar 2017 at 07:38

We have an electronic gate at our main reception which is opened with a button at the reception desk, and then shut again with another button. We have been asked if we can install a timer so that once the open button is pressed, the gate opens, and then shuts again after x amount of time.

I've pulled it to bits and found that this is the PLC controlling it. I've managed to track down a manual which I *think* is the correct one, but I'm not 100% sure.

My first question is, is there a way to change the logic on this controller without Mitsubishi's digital operator (assuming that this is the correct way to program the PLC)?

This is a bit of an adventure into the unknown for me so it'd be great to pull it off, if anyone has any tips, please bestow upon me your wisdom!

Cheers

Brycheiniog · 27 Mar 2017 at 08:17

How will you stop the gate closing if there is somebody/something in the way? Does the gate already have sensors?

In terms of reprogramming I *think* you need this: http://www.essentialautomation.com/ea0087.html

I have no idea if you can pull the existing ladder logic from the PLC though so you may have to redevelop the application from scratch..

Diddums · 27 Mar 2017 at 10:59

That's a good point about the sensors actually, just as well you brought it up. There is no provision for presence detection so if the gate closes and someone's there, they'll get stuck. I'll need to speak to the powers that be about this one.

Swifty55 · 27 Mar 2017 at 11:16

Ask the CAIXA ECONOMICA FEDERAL to finance the installation.

Diddums · 27 Mar 2017 at 11:19

ron3003 · 27 Mar 2017 at 11:32

I'd think carefully before tampering with the closure electronics, you could be held responsible should there be an accident. Surely the manual button is there as it's expected the operator would check nobodies in the way before pushing it.
http://www.bbc.co.uk/news/uk-england-manchester-34849153

Feek · 27 Mar 2017 at 11:44

Without adding sensors to detect the presence of anyone or anything which could be blocking the gates, I really don't think this is a good idea. I'd imagine your gates would have some kind of maintenance contract, perhaps it's worth talking to the supplier to see what they can offer.

skyripper · 27 Mar 2017 at 12:01

Timers on gates are bad.

Take one automatically closing gate in a car park. Take one hire car. Add a sprinkling of snow and ice and lack of traction.
Result was very expensive for the landlord.

Brutal biff · 27 Mar 2017 at 13:24

Your talking about auto close feature the gate control panel should have this feature already safety measures need to be met tho via safety edges and photocells

Django x2 · 27 Mar 2017 at 16:54

Not being funny, but this has "commonsense facepalm" written all over it. If there is no presence awareness, this is a Health and Safety issue ready to bite you squarely on the backside.

Brutal biff · 27 Mar 2017 at 18:27

Django x2 said:
Not being funny, but this has "commonsense facepalm" written all over it. If there is no presence awareness, this is a Health and Safety issue ready to bite you squarely on the backside.

It should already have safety equipment but could do with more info

Ive worked on electric gates in the past now work on industrial high speed doors

Not worked on that plc before tho

Is it a sliding gate or swinging gate
What safety functions does it have ie any radars ,photo cells ,safety edges

Is it used for pedestrian or vehicles

Thekwango · 27 Mar 2017 at 18:40

Firstly, as already pointed out. No presence sensors then no timer control. Too many things to go wrong.

Secondly, apologies if this sounds offensive but if you have been asked to add a timer and there's no one within your team with the skill set already to do this then I'd suggest not to 'brown nose' and simply tell your boss - nope can't be done, at least not by me/us