Upgrading voting system

[Bob Dupree]

Keith, thanks for the hyperlink. I believe that most of that discussion was concerning statewide and national voting machines. I didn't read them all, but that was probably much more involved that our requirement.

 

[rsdoran]

Bob to answer your question I am a 52 year old tech now enrolled full time at UAB in quest of my Engineering degree. I am not as qualified as most here but have dealt with several brands of PLC including AB, GE, AD and more.

I was not sure of what cost issues may be involved so I did not mention some other ideas. One of those may be using one PLC with networked touch screens but that would take some thinking before I could offer specific details on how to implement.

Is it standard in a voting process for members to be allowed to continuously change the vote, I would think it would be more effective if the vote was taken once by each member per each item. The reason I ask is it would create the need for a more in-depth program and/or create havoc with the vote tally and data acquisition aspect, which could be overcome but development time would increase. I guess there could be several reasons for this, people would see how the majority are voting and/or how their "opponents" are voting.....

www.softplc.com may also be of interest.

There are numerous approaches, I can even think of some that are all PC utilizing software and touch monitor terminals, no I/O or buttons involved. The referendum (or item to be voted on) would be displayed on each screen and the members vote by pressing Yes, No, etc.

 

[elevmike]

Bob,

It seems that your task is to setup a voting system for a legistative chamber, Like Congress or a State House of Representatives???

Additionally reading through your posts, it seems that there was a change in direction from retaining the existing mechanical switches to installing touch screens. Great idea....

Anyway here's a small touchscreen that you can network. http://www.ezautomation.net/products/pdfs/ezcetouchpanel_spec6colorstn.pdf


I'm gonna say that though a PLC might do the job, if you go with touch screens then you might be better to consider the Soft PLC.

If you retain the existing switches, (3 or 5?? per desk??) So each switch is momentary?

Sounds like a lighted pushbutton:
http://www.idec.com/Products/ENG/Switches/SwitchA8_us.html

Anyway if you retain the lighted pushbuttons you could network something like up to 240+ Automation Direct DL-06s togeather on a two wire RS-485 network. Each PLC might be located in a small enclosure near a group or row of desks in the chamber and take hardwire inputs, and provide hard wire outputs from up to 16 or less desks (presuming 3 switches and three lights each) in that row. All DL-06 PLC would be network on the same cable to a "Master" DL-06, or PC that would poll the network and report the results to the master display. The hardware cost on such a system would be about $500.00 per maybe every 16 desks, or less then $40.00 per desk. Add some $$$ for the master and cableing and new pushbuttons maybe. A quick calculation based on your previous posts indicate that you might spend about $7,000.00-$10,000.00 for all hardware and cableing, software etc..(not including the big display system).

Each PLC would have identical programs but have a unique node address. Programming the remote and master PLCs to simply report "desk 75 votes Yea" is quite simple. After the final voting is tabulated the master would command all the remotes to reset and turn off the indicators.

 

[rsdoran]

Mike that addressed hardware but wouldn't it require the old wiring removed and new wiring to be run? He did mention a big display that is initiated by the vote input...I am not exactly clear on those details but I think at least 450 outputs are involved but multiplexing may be possible to lower that count, the existing wiring may require multiplexing.

I would think rewiring may cost at least a few thousand if not more and require longer downtime. Another aspect since this is in more of an office environment is all the hardware would be in one location making it easier to "troubleshoot" and work on if necessary.

 

[Doug-P]

It's not a PLC but,

Perhaps something from opt022 would be useful to you.

 

[elevmike]

Doug,

The Opto022 stuff is way more expensive then using a PLC for dummy I/O interfaces... Just my opinion...

Ron,

Actually we would obiviously need to know more about the layout and actual existing wiring,...but it's likely that much of it could be reused.

The existing wiring to the switches presumably are run in a conduit/wiriway to the closet. Bob could either install the 7 DL-06s in the closet and terminate directly to the PLCs or he could inturupt the wiring at the end of each row or section of seats and place the PLCs there. Either way since supposedly since the wirway's already in place it shouldnt be too diffucult to run a a few twisted-sheilded pair in the existing conduit (for power & communications).

On more then a few occasions we've replaced 60+ conductors with remote I/O by using the existing wiring, with three wire Dupline. You end up with tons of spares...So that might be an option also.

With Dupline you'd require a master the one 4-in 4-out board for each desk. The three wires go to all 105 desks, (existing wires re-configurated in the closet). The wires woild be 1 signal, and two for 24vdc power. The master could interface with a PLC in the closet, or it could interface with a softPLC.

 

[Doug-P]

The Opto022 stuff is way more expensive then using a PLC for dummy I/O interfaces... Just my opinion...

Could well be. I was just throwing it out there as one option. It would have the (questionable) advantage of eliminating the PLC intermediary.

 

[Bob Dupree]

Hey rsdoran, Elevmike, and Doug-P
Thanks for all your interest and input. Just want to let you know some of our latest findings. I e-mailed softPLC and got a phone call from Cindy Hollenbeck of that company. The company was founded in 1983 by Richard Hollenbeck, obviously her kin-folk. Anyhow, she is extremely knowledgable and helpful and understood just what we were wanting to do. Our data systems manager and I talked to her yesterday afternoon, and she seems to have a very easy solution to our problem. And, I might also say a very inexpensive solution too. We are going to talk to our bosses next week and probably have someone from softPLC come over here soon. I want to thank you guys for all your help. Ain't the internet great? Again, thanks so much.