Computer Linked To Plc??

I AM DESIGNING A CONVEYOr system that will be used in the dry cleasning industry. it will automatically send clothes to the proper rail for differnt stores. it will be used in large central plants where they are doing the cleaning for 5 or six stores. what i do not know how to do is connect the plc to the compter system that the cleaners use to make there tickets and keep up with the orders. they use bar codes and handheld scanners. i need to use the computer to tell the plc which rail to put the clothes on any ideas or help greatly appreciated

Do you at least know the brand and the type of PLC used? That, you see, is quite important for the correct answer...

32racer said:

what i do not know how to do is connect the plc to the compter system that the cleaners use to make there tickets and keep up with the orders. they use bar codes and handheld scanners. i need to use the computer to tell the plc which rail to put the clothes on any ideas or help greatly appreciated

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Well, it sounds like you have it narrowed down to about several hundred hours of research to get this working. There are several things that you are going to need to know about their "computer".

SCADA Package

It sound like you need a SCADA (supervisory, control and data aquasition ) package. The best around is CITECT. Very user friendly if your PLC/computer savvy. They range from 75point to unlimited and are used world wide for operator interface terminal software. You should be able to pick up a fully functional package for free which will let you test all you want but will shutdown after 20 minutes. Check with the Citect website.
Regards
Steve D

Welcome another Citect fan. Have you tried others? I have and come back to Citect every time.

Another option that can run your barcode system is SQL server we currently run our Omrons to a Noax touchscreen sending the data in Ascii. This in turn goes to the SQL/AS400 data base then the resultants are returned to print the labels from the Datamax printers.

In essence there is nothing unusual in your application however you need to determine what PLC your using. What software on the PC is needed. The scanners won't be a problem as they usually transmit in Ascii. which printers your using. Keeping in mind tyhat they will usually accept half duplex only. again in ascii format.

As 93lt1 mentioned, you need to know something about the "computer" both hardware and software. Is it a PC? How is the data stored? Is it multitasking (Windows) or some realtime opsys? Is it an open system? If data is stored in an open database like Access or Paradox, then there are a lot of tools and possibilities around. Else, if this is an old DOS-system or some properitary program, you may forget about the whole idea of system integration. Unless you happen to know the programmer (and have a gun pointing at him/her). If this is not an open system: start from scratch with CITECT or Wonderware or some other SCADA software like Steve D suggests.

Helge Slettvoll

tracking

I realize there is a lot involved in this project, but here are a few hints.

Include the store assignment as the last two digits in the barcode, then strip the rest of the digits off. Use that to compare to a lane (store) assignment. If compare equal then activate diverter when product reaches the divert point. The divert point can be determined with a pulse encoder activating a counter and using a value equal to the distance. I know that there is a whole lot more than this, such as bit shift instructions and counters to keep up with many packages in process at the same time. For this process, the barcode labels were printed and assigned at the beginning.

The data flowed something like this. The barcode was scanned, the scanner was attached to an ASCII to DF1 interface (AB).The ASCII was retrieved by the SLC500 PLC, there the barcode was stripped out as outlined above. From there, a PC was attached to another port of the ASCII interface. They used a simple Visual Basic program to transfer the complete barcode data into a MS ACCESS database. The ACCESS database was then read with ORACLE software to get the info to the AS400 mainframe.

I hope this will give you at least a little help.

Sid