That is a tall order.
I started controls with all electromechanical logic.
Years ago ,I had to make a control sequence of operation using
relays ,contactors,solid state time delay relays,lock out relays
temperature ,humidity,conductivity ,time schedule, pressure, voltage/current liquid level and speed controls.
There were snap acting ,motor driven ,and series 90 modulating controls.
The logic or programming / commissioning has not changed.
Air conditioning, boilers and chillers still operate in the same basic way.
They have solid state controls attached to them, but
fuel filters and fan belts
are still changed in the same way.
Can you read and understand a schematic?
D.D.C is a tall order.
I would seriously tell you to look into classes,either
through vendors or at trade schools.
When I started out digital controls were programmed
through a small keyboard and even small potentiometers.
The laptop has become a standard control tool.
That also means a basic understanding of Windows is also required.
I have posted many questions here,and got some very good solutions,
on just connecting to a controller, let alone how to commission it.
The basic text books, and there are plenty of tutorials
on the web,will
give you the basic components such as input and output types.
There is much more after that.
What is a good internet tutorial?
Surf around and any tutorial that you can understand after a paragraph or two, is a good site.
The question is, how deep do
you want to get into D.D.C. ?
On the job training backed up with classes is the best way to learn it
Anything based around open systems is key. Which brings you to Tridium as a front end system that you will want to learn. You can get training on tridium based controls from any authorized Honeywell Automation distributor. Not sure where you are located but if you go to www.cgnacontrols.net and go to their member locator you can find a great resource in your area. Also, you can find great free training videos and information on ddc controls at www.controltrends.com
Our very own lonboy contributed to the writing of this book.
I used it exclusively to prep for my lonmark exam. http://www.enerlon.com/
I'd highly recommend taking one of his classes if you go down the lon route.