Interfaceing PC to PLC

[UK Homer]

Hi

Can any one tell me the easiest and cheapest way to interface a PLC to a desk to PC using either Profibus or MPI on seimens PLC's without having to by any hardware if at all posible as I would like to use the PC as a HMI without having to buy scada package. This is just a pet project but I would like to play with it and learn so can anyone help me. Somebody can't remeber who told me it was possible to interface to MPI using 2 RS 232 ports on PC does this sound right or not?

Please Help

[Pierre]

The cheapest way is for your time to be valued as ... nworthless.

Say you work nightshift and most of the time your on standby.

OK, get a PC and play.

Trough books and the NET, you should be able to gather enough info to write a driver so you can use it with Visual basic or any other Visual tools to build your own little SCADA...

This is very slow.

A bit faster is to purchase from eBay some driver (mostly Activex) and incorporate them into a Visual Basic application.

Still not an easy task but for less than 50 bucks you can be on your way to very fast passing nights.

Enjoy

[UK Homer]

Pierre

You are correct in your assumption I do work 12hour night shifts on a regular basis and because of only waiting for things to go bang I do have a lot of company time on my hands. Having said this I think I have all the software I need to get started it is just the physical hardware connections in order to connect the PC and PLC?

I do value you my time that is why I like to play with stuff like this just to learn especailly when some one has told me you can't do that because I always say nothing is inpossible it is only not possible until some smart B*S***D proves it can be done. Plus next time some bright spark manager gets a pie in the sky idea I might just manage to come up with a solution from what I have learnt.

bonkhead

[userxyz]

Look:

Download edonkey, from www.edonkey2000.com

search for siemens or simatic,

That's how I got Protool 6.0 and WinCC

For S7 we have the license disk en protool to. But not for WinCC.
Look, u may download it from edonkey, but I would never use it in industry, it's your choice,

but u can get it for free ( illegal !!!!!! )

greetz,

CoMBo

[Pierre]

Perhaps my knowledge of the english language is so bad that when I want to say something, it comes up with a different meanning.

I've seen in the past, crews of many technician doing rotations on the night shift.

ALLWAYS, there was one in the group, which learned so very technical stuff. This guy would build interface to PLCs, setup parrallel networks and play with all of the technologies he could incorprate into his "toys".

After a few years he would be a "Top Gun" player in his companie. The others where very good at F1-Racing and other simulator

I could only admire what he knew. I would sit down with him and ask him a lot of questions on how he built these things. He really did work a lot...

Wothlees time... when I said this, I meant... sitting and waiting for things to happen. Like on many night shifts. The one who takes this time to learn is transforming this value of zero into the equivalent of thousands of dollars of trainning. The nice thing about it is that he also can use the many available device he as in the plant. It's even better than night school.

I say Bravo to UK Homer.

Only one thing to be carefull about... Don't think that what you custom build is good to be install in the plant. It could be very good when you are there but it as to be a standard item... for the long run of the plant.

PS: Guess what this learning gave them? Mobility.

[UK Homer]

Thanks Pierre

I think I misunderstood your origanal post So I appologise this is exactly what I am trying to do change the boring night shifts into a chance to learn and get a head. I am really hungry for knowledge however I still would like to know how to connect my PC to PLC in hardware without the expenses of by either a profibus or MPI card for the PC.

Any one who knows anything on this subject please give me a clue?

[rsdoran]

There are numerous sites on the net that give out software codes etc for the Siemens BUT most of the state the same thing, BUY the adapter cable. Note the adapter is different for S5, S7-200 and S7-300, unless you get the CP5511 pcmcia card(very expensive) which works with all 3.

I have looked before for the adapter specs but didnt locate them, will look again but for some reason the MPI thing seems to be difficult, I am not sure about using Profibus. I will investigate it.

[andre]

Hi people,

Please sorry my english,

Homer,

I made a PLC interface to a PC (Intel 386, 8MB RAM, no HD, booting from floppy and creating a RAMDrive) using the freeport mode of the S7-200 series. The computer was found on the trash room (obviously) of my office and I used it successfuly as a HMI, is instaled and was cheaper then a TD200 or a TP070. On the CD Tips and Trick of the S7-200 there is a tip (52 I think) that teach how to use the freeport mode to comunicate with a PC (half-duplex). QBasic can be used to build a simple comm program (show variables of process an send simple commands by keyboad). You may use a visual language (VB, Delphi, Visual C++) and build a good looking HMI, but this was not my purpose.

[Pierre]

Since you do have some spare time...

Here is my 2 cents...

Get a free demo HMI from the NET
Get a copy of Win Ice

Enjoy!

[dgottfried]

Homer.. I have been in the same situation as you. Using an HMI software called Interact downloadable from www.ctcusa.com. This Software includes the drivers to interface to a S7-200 CPU. No development of drivers needed. All that you need to do is develop your HMI screens. (In Demo mode) Connect a RS-485 cable from the PC to the PLC. (Diagram available in the HMI software help) When your screens are developed, you can run the screens. The HMI workes the best on a 95 or 98 PC.

[TimothyMoulder]

Pierre - a few expressions for what you were trying to say, and places they can be used :

General : "Idle Time"

Meetings : "Non-value-added Time"

Co-workers : "Moulder's f*cking around again"



TM

[JesperMP]

Homer.

You wrote that you would like to use MPI or PROFIBUS for comms.
Then there is a PC/MPI adapter for the serial port (works also on PROFIBUS)
Siemens type 6ES7972-0CA23-0XA0 (+ cable 6ES7901-1BF00-0XA0) - price: approx € 280.

The problem is how to communicate over MPI from your application (VB, Deplhi, ? ..). MPI is a proprietary protocol from Siemens, so I think that to develop your own driver is an impossible task.

You can get PRODAVE MPI which is a DLL type library (for Win95 only I think).
Siemens type 6ES7807-4BA00-0YA0 - price approx € 400.
PRODAVE MPI MINI (dataexchange within DBs only) for approx € 200.

For Linux you can try to look at LIBNODAVE that somebody is working on.

There are also various OPC servers for both MPI and PROFIBUS.


hope this helps.
Jesper

[jvdcande]

Homer,

if your goal is only to learn about SCADA and HMI, then try the Citect SCADA package. You can download it from their site, all drivers are included and the application you're building with it will run for about 15 minutes without key. I use it continuously to teach people the basics about SCADA. The PLC I'm using is a S7-212 and the communication is done over a PC/PPI converter, which I already need to program the PLC.

This is a very low-price solution, which has proven it's efficiency.

Good luck!

Jean Pierre Vandecandelaere