scootabug

Care to do some name dropping? As good as I am at Googling, "PIC I/O board" is a tad vague. And I'll be sure to check out the Nuts and Volts magazine web site. Thanks for all the help!

Thanks

Hey Everyone, I'm very new to PLC and this is my first post to the forum. Let me apologise in advance for not understanding some of the lingo getting about! Here's my scenario... I need to set up a 24v computer-controlled system (it's going in a motorhome, don't want to use 240v) that will control lighting circuits, trigger other devices (an electric awning for instance or a projector screen), read values from thermocouples and water level sensors from diesel, water, grey water and black water tanks. It also needs to read the status of NC switches to indicate if a door is open etc. All in all, I have roughly 30 Digital Inputs, 3 Analog inputs, 2 Thermo Inputs and perhaps 12 Digital Outputs (these are questionable, keep reading ). I know I can have this many I/O with the additional modules I have ordered, just curious about their functionality. At the minute the plan is to run an AB MicroLogix 1200 PLC w/Ethernet module plus other I/O modules to support obvious digital I/O. I will be running a Windows Server with Invensys Wonderware (if their sales team would ever return my call) to be a HMI to the ML1200 via Ethernet. All I need Wonderware to do is show pretty gauges for tank levels, temperature values in text and have buttons for the light circuits with sliders/buttons to increase/decrease/on/off etc. Seems simple enough, given I know nothing. The main part of this I am concerned about is the new requirement of light dimming. I have about 10 light circuits (24v DC, LED down lights, can be dimmed by controlling voltage), that I was originally just going to switch on and off via a relay, hence the comment about questionable 12 Digital outputs. Questions: Has anyone used Wonderware with an ML1200? Am I asking too much of it? Is there anything I should know before I make an order? What is the easiest way to control the voltage to the light circuits to be able increase and decrease the voltage? Lets say each circuit operating at say 1amp at 24v (which I thinks put it over the power requirements to power it directly off an analog output of an AB Analog I/O module? Correct me if I'm wrong! Is there anything unrealistic as far as my requirements are concerned? Sorry for the seemingly long rant for what could have been summarized quite easily. I just wanted to ensure you had the full picture. I'm keen to see your response! Thanks for your time and your generous support. Scott