Help deciding !!

Hi guys,

I need some help deciding on what PLC should I use.
It's for controling some pumps and stuff. I've worked several times with PLCs, but now I need to be able to programm and control it through RS232 or RS485 from a java programm. Cost is very important!!
I've been looking into the mitsubishi's FX family an the Simatic S7.

Thanks !!

I can't recommend either. I don't think I've ever done java. If I did, I sure didn't know it.

Quite a few guys on here will say to go with the S7. And they know more about siemens then I will ever.

Do a search on the Mitsu unit, here and on google. I think you will get a 50/50 response, or worse, on recommending it.

What about the Allen Bradley Micrologix? There are RS232 DF-1 drivers available for your Java program I should think. Altthough I would say that a dedicated HMI such as a Red Lion controls G3 would be a cost effective solution for controls. I am not fond of PC based HMI for PLC's. OK for SCADA but not operator controls, PC's are generally too flaky. The G3 would also act as a bridge to an ethernet network for your PC for data collection.

Ain't gonna get in this game...

But then, having posted, I guess I got in the game... however, ain't gonna lay.

There goes Terry, taking the safe way out...

There's nothing wrong in being safety conscious. And if you can't be safe...be careful and if you can't be careful....buy a buggy.

Could be a whole new way of life for him...

Drive a buggy, wear black, no electricity...

Unless you have a really compelling reason to use Java to interface to the serial port, I'd strongly advise you to use another language. Java (being largely platform independent) really falls down when it is called on to interface with hardware since it has to deal with the messy details of the OS.

Consider something like VBA instead - it took me about 3 days to get an example Java serial port app working (badly) and about 30 minutes in VB6. That said, the javax.comm for Windows control is available online if you want to play with it and see for yourself.