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Simple and easy PLC
So many PLCs, so little experience...

Hi, I want to buy a very simple PLC, and write a 3 or 4 rung timer circuit with a counter or two. But I am old school, and I cut my teeth on Allen Bradley PLC2 and then on PLC 5. Not much programming experience but I used them lots and lots for troubleshooting process control stuff.
SLC 50's are a little after my time, but i know there are some nice little models out there. I need to turn dry contact on and off 500 times or so about once per 5 seconds.

And another function to start a 24v ac or dc motor (miniature)(to spin and magnet to test a rees switch) and output a 5v dc pulse through a reed switch and count the pulses through the switch and compare it with the accrued value on the PLC counter.

My programming is way rusty, so the easier to program the better...

Appreciate any help or advice, honest.

Jery H.
Georgetown Texas

By Steve Myres, PE on 3 February, 2004 - 4:26 pm

Sounds like a good application for an Automation Direct DL05. 8 in/6 out, with some models at $99 depending upon I/O flavor and type of power input.

By Sandy Chapman on 3 February, 2004 - 5:01 pm

Dear Jery,

the PLC that you need is the Omron ZEN-10.This is a very simple and multifuntion PLC, some ZEN-10 models have a lcd display for ladder programming and system monitoring, analog inputs and more important features. You can get information about it from Omron home page.

Sandy Chapman

By David Adams on 3 February, 2004 - 5:08 pm

Take a look at the Millenium from Crouzet.

Jery,

Entertron offers an inexpensive controller with free programming software and cable that will handle what you are looking to do.

Hope this helps.

God Bless,
Stephen Luft
Entertron Industries
3857 Orangeport Rd.
Gasport, NY 14067
Tel: 716-772-7216
Fax: 716-772-2604
web: www.entertron.com
wwjd - wdjs

By Michael E. Crossman on 3 February, 2004 - 9:57 pm

You might look at the PICO controller from Allen-Bradley

http://www.ab.com/plclogic/pico/

Good luck

Michael E. Crossman
PLCs Plus International, Inc.
http://www.bkppi.com

Look into the Allen-Bradley Pico or any of it's clones from moeller, siemens, etc.

Program it through the keypad on the front. A-B has free software, but you have to buy the cable.

Good luck.

By Mike Richmond on 3 February, 2004 - 10:07 pm

Jerry,

An extremely simple option might be the Allen-Bradley Pico controllers. They're (relatively) inexpensive, there is free (as in beer) programming software available for them (from AB), and/or they can be programmed from their front panels.

AB used to advertise them as 'smart relays'. Might be worth a look.

By calvin smith on 5 February, 2004 - 12:01 am

Good afternoon Jery,

what about a smart relay? you can program from the keys on the relay (no software needed). you can get them from IDEC, SQD, OMRON, ECT. They work well, but check on the timing bases. some models will only program in full seconds. I have used one to control a glue system and operate a 2 speed control for the drive motor.

hope this helps
calvin smith
smithgsk@netscape.net

By Matthew Richardson on 5 February, 2004 - 12:01 am

Check out the seimens LOGO, get the starter kit, it comes with a LOGO (check voltages first) programming softwear and programming cable.

Can be programmed in function block (to Easy) and or ladder logic, great to use and programme

Regards Matthew
vk7juf@southcom.com.au

By Dean Norton on 5 February, 2004 - 12:10 am

Jery,

Try the WAGO I/O System - you can get a controller and software for less than $1000.00. It will let you add I/O in 1, 2, 4 or 8 Channel modules so you only buy what you need - no waste with 16 or 32 Channel I/O cards. Check out their site at http://www.wago.com or call 1-800-346-7245 for free application support!

By Steve Myres, PE on 7 February, 2004 - 1:00 pm

Dean,

I viewed your previous posts on other threads favorably as an attempt to publicize a product that arguably has significant advantages over the alternatives. Suggesting a $1000 solution to this request just seems crass and indicative of a "sell what we got whether it fits or not" mentality. I hope I'm mistaken and you misunderstood the query.

Steve

Steve,

Not sure why you think this is Crass. He mentions another PLC brand which is going to cost him more. Several others on this thread have suggested various PLCs but I am willing to bet that the controller and software are much more than $1,000.00. He did not say he wanted the cheapest PLC - he said he wanted a simple and easy PLC that fit his budget. At least that is what I interpreted. I am simply trying to give people an alternative to the "BIG GUYS". I apoligize if this came across as something different.

Sounds like you might need to do a little research on this application. Im not sure if I read your output function correctly or not. Did you mean 500 time every 5 seconds as in 100hz? If so a dry contact isn't going to work... it can't physically respond that fast.

As for the reed switch and magnet test, how fast will the motor be spinning? How many magnets on the disk? You have to be careful here too because if the frequency is too high you will need some sort of high speed counter feature on the PLC or you will miss counts due the pulse frequency exceeding the scan time of the processor. This probably won't be a problem with a true magnetic reed switch because the switch cant operate that fast. A solid state switch on the other hand can be.

By Curt Wuollet on 5 February, 2004 - 1:02 am

A 10 point Micrologix with the free software might be
comfortable for you. I would use my LPLC.

Regards

cww

Siemens SIMATIC S7-200 PLCs would be another cost efficient and user friendly choice.

By Gabriel Villarroel on 5 February, 2004 - 11:41 am

Have used PICO system and OMRON, not Automation Direct. Though not low cost. Foxboro Archestra (2500) is the easiest and fastest system you can program. Though Foxboro doesnt cosidered it a PLC, cause its really a DCS, you the application you asked for running under 10 minutes.

Surf on over to Rugid Computers and have a look at their Rugid 3.
http://www.rugidcomputer.com
It's drag and drop programming that's very simple, and fairly inexpensive.

Mark Hill

Try the Modicon Twido with software Twidosoft. Very small form factor with some networking capabilities as well...will do Modbus 232/485 or could potentially go Modbus/Ethernet with the 174CEV30010 module from Modicon. All in all, the Twido form factor is palm sized and can do what you are asking. Twidosoft software is ladder/rung type with very simple easy to use instructions.

www.modicon.com
For more information or email me at
engineer@caddtractor.com and I can send you info.

Rick

try this Trilogi PLC
http://tri-plc.com/