Besides a screwdriver my laptop is my most used tool. Ours are set up with Service Tools which allows me to look @ ANYTHING that may be going on with a chiller or rooftop. I can run trend logs ( great for proving your point) , look @ and clear current alarms , make many more adjustments alot quicker than using the controllers , and so on. All of our IM's , OM's and parts books are on my lap top as well. Makes it super easy to look up part #'s and call our parts girl with them in hand. It takes the confusion of trying to explain what part you need. We do not have wireless connections yet to look @ jobs while laying in bed but that is comming soon enough.
They are the wave of the future in our trade. Pretty soon reisdential units will have to be fixed with a laptop as well. The time is here kids , do not try to deny it or you will be lost !!