molding machine

[mjankovski]

can you give me some web adress or some information about controling injection moulding machine with microcontroller?

[Belleblaas]

I do not reccomend to use a uController (read next text).

With this kind of machines you are subject to several guidlines.
To be prepared for the future I believe you should use a by industrie accepted common hardware system like PLC or (embedded) PC.
You might need to implement some kind of fieldbus interface or ethernet.

I do not know which country you are from but be sure to follow the follow the European standards if living inside Europe.

There are European standards for controlling, interfacing and implementation of injection moulding machines.

There are specifications for for several things.

Please visit the Euromap website :------ www.euromap.org ------
There you can find the documentation presenting the guidelines (recommendations).

There are 80 main documents of wich some are divided into sub documents.

From ealier experiance I do believe there is also a harmonized version of this standards.

Maybe my reply is a littlebit long but keep in mind that in Europe and possibly outside there this recommendations are verry appriciated.

I hope all is clear to you but if not rely again so maybe we can exchange email addresses.

Hope to have served you with this...

[mjankovski]

thanks Belleblaas for your answering.

BTW, I am from an European country - Macedonia (maybe you haven't herd about this country, or you heard about FYROM - that's the same country)

So, my country is litle "slow" in upgrading to new technologies..
Don't be suprised if i tell you that, for examle, molding machine aging from 1990 is rated as "relatively new" machine. (Although the machine is old more than 15 years:))..). So, I have couple "new" machines, and one old machine (Kraus-Mafei 1978). It's old, but verry useful, and also have big screw diametar, so I dont want to give up from it. My Idea for Microcontroler was to give the old Krauss new life:), because the Krauss automatic is made by relay technic. I want to change that relays (because there are less and less spare parts) with PIC.

You recommended me a PLC. I don't know what's the diference between PLC and PIC, so, if you can explain to me.. And if you could tell me is it worth to make that changes, or...?

[Tomi Engdahl]

A Programmable Logic Controller (PLC) is a ruggedized special purpose computer that reads input signals, runs control logic, and then writes output signals. They are used in factory production line automation mostly, but can be used in very many other applications also.A PLC (i.e. Programmable Logic Controller) was invented to replace the necessary sequential relay circuits for machine control. The PLC works by looking at its inputs and depending upon their state, turning on/off its outputs. The user enters a program, usually via software, that gives the desired results. PLCs are used in many "real world" applications, like industrial control. If you are involved in machining, packaging, material handling, automated assembly or countless other industries you are probably already using them. Almost any application that needs some type of electrical control of machine has a need for a PLC.

A PLC works by continually scanning a program. First the PLC takes a look at each input to determine if it is on or off. Next the PLC executes your program one instruction at a time. Finally the PLC updates the status of the outputs. It updates the outputs based on which inputs were on during the first step and the results of executing your program during the second step. In the beginning all PLC implementations were proprietary, but nowadays there is standardization in this field going on.

The standard interfaces used in PLCs are most typically digital input (24V binary input), digital output (solid state or relay),analog input (4..20 mA current loop) and analog output (4..20 mA current loop).

The PLC is basically a ready made device that includes a microcontroller, interface electronics (between real-life industrial typically 24V very robust interfacesas and microcontroller 5V logic signals) and a special control software (designed to work reliably and have pissibly built-in safety features).

More information on PLC can be found at http://www.epanorama.net/links/automation.html#plc

The diference between PLC and PIC is that the PIC is just the bare microcontroller IC, while the PLC is a whole tested product based on some microcontrontroller.

You can built a PLC like device based on PIC. Then you need to add some electronics aroudn the PIC (input and output circuitry) and then your control software that does the necessary controlling. It is possible, but time consuming to do this all. Designing a device that will reliably work on hard industrial environment is fat from easy. Baddly designed simple PIC (or any other microcontroller) based circuitry can easily "crash" / fail / get damaged if it is exposed to voltage spikes you can see in industrial control enviroments.

[Belleblaas]

Dear Mjankovski,

First of all I think if you do not want to give up your old machine..give it a new life instead of investing money for a new one.

Of course you can use a uController to control you machine but this will demant engineering of soft-and hardware.
Next to that is possible your machine has to comply with CE regulations so your uController board is to be tested for this standard (EMC etc.).

Using a standard PLC (Programmable Logic Controller) e.g. Siemens, Beckhoff, Mitsubishi. You do not need to worry about this standards.
The PLC is a standarized piece of harware wich may contain a PIC or something like that.

Programming the PLC can be done using IEC61131 standard software wich makes it quite easy to translate you ideas in to a working system.
If you system is not to complex try Mitsubihi Aplha controller, Siemens Logo or Moellers Easy

You will be suprised to see how easy its to program with this systems (mostly graphical).

Next to that you are able to implement fieldbus, ethernet and or SMS into you application.

I cannot explain the difference between a PIC and a PLC here but I am sure you can find info on Internet.

Kind regards,

[belleblaas]

I did not see Tomi's reply but it says all I believe?

[BradandPitti]

cool site :-)