Need assistance choosing a PLC

[Raynentye]

I need a PLC, preferably compact, rail mounting, 24 VDC, with at least 8 discreet (digital) inputs, and 8 relay outputs. I was looking at the inexpensive TECO SG2-20VR-D. I downloaded their SG2 Client software. Designed my circuit on it, and activated the simulator. Unfortunately, it didn't work out as planned. I'm quite used to microprocessor programming. This just seems really easy to do. So I really doubt I did this wrong.

Real world terms, this is what I need it to do:

When input 1 is activated, relays 1, 2 and 6 must activate. After one minute, the relays return to the unenergized state.
When input 2 is activated, relays 1, 3 and 7 must activate. After one minute, the relays return to the unenergized state.
When input 3 is activated, relays 1, 4 and 8 must activate. After one minute, the relays return to the unenergized state.
When input 4 is activated, relays 2, 3 and 7 must activate. After one minute, the relays return to the unenergized state.
When input 5 is activated, relays 2, 4 and 8 must activate. After one minute, the relays return to the unenergized state.
When input 6 is activated, relays 3, 4 and 8 must activate. After one minute, the relays return to the unenergized state.

I understand that I am not using relay 5 as well as inputs 7 and 8, but I'm going to use this at a later point in time.
I didn't set up the timers yet, I just set it up for toggling just to see if it'd work.

Is there a PLC out there that's able to do this? Am I just missing something with the programming? I'm attaching the ladder file I designed. It is really extremely simple. I'm just wondering if its beyond the limits of the PLC itself. I'll be grateful for for any help. Thank you.

 

[itsmoked]

An input, a timer, a N.C. logical contact, controlling three outputs.

Why can't the Teco do this?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[samtorres66]

AB Micrologix 1000 32pt I/O can easily do this application.
With plenty left for other stuff. Draw back - no online editing.
AB Micrologix 1100 has an ethernet port and online editing features. However, you might need to add a output module.

 

[Raynentye]

I'm wondering if it has something to do with limitations of the Teco simulator. Once the ladder circuit is designed, I started the simulator. Upon initiating input 1 , only output six activates, input 2 activates nothing, input 3 activates only output 1, input 4 only activates output 7, input 5 only activates output 2. Input 6 is the only one that works correctly. It activates relays 3, 4, and 8 as it should. What's really confusing me is how simple the circuit is and it just isn't working! I must be missing something even though its right in front of me.

Thanks samtorres66, but the AB Micrologix 1000 is a bit large. I'm trying to keep it as simple as possible. However, I'm going to keep it on the back burner just in case things don't pan out with the Teco.

 

[bkemp]

Have you checked on a Siemens S7-200. I have used them with 14 inputs and 10 relay outputs. It has a compact footprint. I do believe the programming software is included with the PLC and is Windows based.

 

[ScottyUK]

An S7 for this task? Not so much using a sledgehammer to crack a nut as using an atom bomb...


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If we learn from our mistakes I'm getting a great education!

 

[Raynentye]

I think the multiple outputs mapped with multiple inputs is confusing the simulator. Is this common with other PLCs? I understand the Teco units may be at the low end of the PLC spectrum and maybe that's my problem. I need a higher end PLC to do this job.

 

[itsmoked]

Is that file you posted your program? When I opened it in my version it was blank.

If it is I will upgrade and take a look. Frankly a TECO is almost overkill for this.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Kiljoy]

Siemens makes the Logo programmable relay. They even have expansion modules with analog now. You can buy one around $200. The software is a bit watered down compared to the Microwin, but it's not too bad.

 

[nagarajh]

Are you able to attach the file in pdf?

 

[itsmoked]

Kiljoy; FYI the TECO is the same thing.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[nagarajh]

I was able to open the program you sent. There is a logical bug in the way you are energizing the outputs. There are multiple conditions energizing relay output. I have attached the correct program. Try this and let me know.

 

[itsmoked]

nagarajh; No attachment.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Using logic blocks(the other programming mode) you can do this that works. This mode seems rather easier too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[nagarajh]

I have attached the file again.

 

[itsmoked]

Nicely done nagarajh.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Earth calling Raynentye..

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Oxidation]

You could try a Siemens LOGO. Programming is graphical & easy. they are also quite cheap & the prograaming software is free

 

[waross]

Oxidation:
You may find these posts interestig:

Kiljoy (Electrical)
17 Feb 09 12:28

itsmoked (Electrical)
17 Feb 09 15:34

Bill
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"Why not the best?"
Jimmy Carter