I wnated to do this using a LOGO ( Siemens Logic Device) or A Schnider's Zelio

Advantages:
Fast implementtation
EMC ESD taken care of my mfg.
Easy programming


Disadvantage:
None of the companies are ready to sell it directly to us
System houses want the project for themselves ,i.e programming and installation,so I become more a trader than a technocrat

Expensive as I am not any system house

So I need to do it using uC..( I hope I could get my hands on PLC 's much easily)

My Dad had to fight with Siemens India to get his first s7-200 PLC,but now they don't even bother to send a price list or quote for requirements


Please show me / Explain a example implementation of opto isolation as I have shown in my flash ..

Thank you
Deepak