How to choose a PLC model???

Hello friends,

I am new in this forum.I've just graduated from the university.I've a project,I need a PLC but I don't exactly know the points when choosing a PLC model?Can you help me?

And also I need help about 'DIFU instruction'.I know the meaning and how to use this instruction but I don't know when I am supposed to use it?Can you give me some examples?

Thank you from now on.

PLCs come in such a wide variety!

1) What is your application? Learning, smalll project, or ?
2) What is your budget?
3) What type of PLC? Micro, rack mount, board type, or ?
4) How big do you need? 10-16 I/O, 20-30 I/O, 100 I/O?
5) Any brand preference?
6) Analog I/O? or just digital?
and on and on...

Siemens is hard for many people to learn. However, I've heard they have good support in your area for industrial users.

Entertron "LINK" has several models that may fit your application. You can call them, explain that you are a student, and ask if they have a package that may suit your needs. Their software is FREE, and includes a simulator which runs without a PLC! I am particularly fond of their SmartPak series, and highly recommend it for any small application.

General Electric has a wide variety of units, but you pay extra for the software if you can not get a Starter Kit" through a local distributor. They do have a 64 I/O micro, which is pretty neat.

Generally, Allen Bradley is expensive, and you normally pay extra for the software. They do have a $99 usd micro, with 10 I/O and free software.

Many guys here like OMROM, I have used them and find them to be okay.

Keyance has some intersting units. They used to have a couple of programming aid booklets available on their site.

Write down exactly what you need and are going to do with it, and post it, and one of us can give you more specifics.

regards.....casey

Schorcher said:

And also I need help about 'DIFU instruction'.I know the meaning and how to use this instruction but I don't know when I am supposed to use it?Can you give me some examples?

Click to expand...

One classic example is given in Phil's tutorial HERE...



-Eric

CaseyK said:

PLCs come in such a wide variety!

1) What is your application? Learning, smalll project, or ?
2) What is your budget?
3) What type of PLC? Micro, rack mount, board type, or ?
4) How big do you need? 10-16 I/O, 20-30 I/O, 100 I/O?
5) Any brand preference?
6) Analog I/O? or just digital?
and on and on...

Siemens is hard for many people to learn. However, I've heard they have good support in your area for industrial users.

Entertron "LINK" has several models that may fit your application. You can call them, explain that you are a student, and ask if they have a package that may suit your needs. Their software is FREE, and includes a simulator which runs without a PLC! I am particularly fond of their SmartPak series, and highly recommend it for any small application.

General Electric has a wide variety of units, but you pay extra for the software if you can not get a Starter Kit" through a local distributor. They do have a 64 I/O micro, which is pretty neat.

Generally, Allen Bradley is expensive, and you normally pay extra for the software. They do have a $99 usd micro, with 10 I/O and free software.

Many guys here like OMROM, I have used them and find them to be okay.

Keyance has some intersting units. They used to have a couple of programming aid booklets available on their site.

Write down exactly what you need and are going to do with it, and post it, and one of us can give you more specifics.

regards.....casey

Click to expand...

Thank you very much for your help at first.Here are the details:

1- It's a project
2- It is 20-30 I/O big
3- I think it is a board type.You know the pLCs used in control panels.That's it.
4- No need for analog i/o.
5- I thought about siemens or omron but I am open to any other brands.

What do you think??

What kind of industry?
What are you trying to start and stop?
What do these devices do?
What kind of environment clean and dry or wet dusty hot etc etc

Dan Bentler

DIFU sounds like Omron. I would suggest a CPM1A "shoebox". DIFU (leading edge trigger) is normally used to "SET" a bit on the leading edge of an input.

leitmotif said:

What kind of industry?
What are you trying to start and stop?
What do these devices do?
What kind of environment clean and dry or wet dusty hot etc etc

Dan Bentler

Click to expand...

It is a aluminium covering system.I have two conveyor to carry the Al profiles into an oven.I have two vacuum machines to control.
The system is in an factory so the environment is dusty and dry.

Schorcher,

In providing additional information regarding Casey's assessment of the Smart-PAK series.

There are two types - one that can be configured for up to 12 in / 12 out. The other can be configured for up to 16 in / 12 out. The second set can have up to two serial ports. Both require either 12 VDC or 24 VDC power to operate. To confirm, the software is free and can be downloaded from our web site as Casey indicated.

If you have any additional questions, feel free to email me at the email link listed below.

Hope this provides you with the information you require.

Please note that I am employed by Entertron who manufacturers embedded PLCs.

God Bless,

Hi Schorcher,

The usual advice I give to people in your situation is to first check what standard PLC is used by the company you are working for. If they have one, use that. Most PLC brands have a PLC in their range that can perform most required jobs. If you use the company standard PLC, they generally already have spare parts available and the technicians are already trained in the use of that PLC.
When deciding which components to use (PLC and other parts), I will often check out the company spare part store, and select the same components that are on the shelf.

Hope this helps.

Doug