Here is the implementation of a program that analyses several days worth of data coming from a sensor that might change a tiny amount over that time. We were interested in how much of a change over time occurred, so I ‘fitted’ a line through the data points that would fit the best and calculated the slope of that line using linear regression using the recommended formula for the sensor and process used: Continue reading →
Ever wonder why Ron Paul would get up and give the same speech everywhere he went, no matter the audience? Why he didn’t waver from his central message of individual liberty? I think it was because he had a different understanding of his own purpose. He was talking to the remnant, just as the prophet Isaiah was:
the Lord commissioned the prophet to go out and warn the people of the wrath to come. “Tell them what a worthless lot they are.” He said, “Tell them what is wrong, and why and what is going to happen unless they have a change of heart and straighten up. Don’t mince matters. Make it clear that they are positively down to their last chance. Give it to them good and strong and keep on giving it to them. I suppose perhaps I ought to tell you,” He added, “that it won’t do any good. The official class and their intelligentsia will turn up their noses at you and the masses will not even listen. They will all keep on in their own ways until they carry everything down to destruction, and you will probably be lucky if you get out with your life.”
Isaiah had been very willing to take on the job — in fact, he had asked for it — but the prospect put a new face on the situation. It raised the obvious question: Why, if all that were so — if the enterprise were to be a failure from the start — was there any sense in starting it? “Ah,” the Lord said, “you do not get the point. There is a Remnant there that you know nothing about. They are obscure, unorganized, inarticulate, each one rubbing along as best he can. They need to be encouraged and braced up because when everything has gone completely to the dogs, they are the ones who will come back and build up a new society; and meanwhile, your preaching will reassure them and keep them hanging on. Your job is to take care of the Remnant, so be off now and set about it.”
After too many hours of struggling though trial and error, packet sniffing, and lots of various materials found on the Internet, I have uncovered a few very important secrets that were not readily apparent in the official vendor documentation I had available.
The device I was working with: Trane UC400 BACnet Communications Interface
In general, none of the BACnet configuration software or documentation makes reference to the number of data bits, parity, or stop bits used. Baud is the only thing that is set. The problem is that unless you are integrating with something specific to BACnet, you will need to set these parameters. Here they are: Continue reading →
It is common to control the speed of a pump based on a sensor reading. But what if you want the pump speed to change at a different rate at different parts of the sensor range? If the response isn’t approximated by an equation, you can break down the response in to segments and use a new equation for each segment. That is exactly what is done here.