Getting a grip on the PID

Wires and shrinking tube to extend connections

In preparation of the arrival of the Fuji PXG4 PID, I got some colored cable and shrinking tube to extend the connections from the inside of the Roastilino to the outside, where they will be connected to the new PID. One does not want the wires to be mixed up so I chose different colors. And yellow shrink tubes to isolate the soldered connections.

Meanwhile it's also time to further study the manual. It's a huge manual with lots of options that one doesn't need for this application, but it seems one needs to learn it all to know what one can safely ignore.

Studying the manual includes a frequent lookup, on the internet, of terms that are assumed to be household words for the reader. Without this wider reading, an intimidating lot remains very obscure, like "Pressing this key allows you to set the function for UTEY under the system menu SYS CH 7".

It's a remarkably versatile little device which could perform a wide variety of tasks. It will control a coffee roaster, but it might as well be used to provide cruise speed control in a luxury car or keep a huge ocean steamer on course in heavy weather.

In fact, the "birth of the PID" happened in the 1920's of the last century when Nicolas Minorsky was designing automatic steering systems for the US Navy. He based his analysis on observations of a helmsman, observing that the helmsman controlled the ship not only based on the current error, but also on past error and current rate of change.

Having someplace to go, some speed to maintain or a certain temperature to approach involves the same process of knowing how far one is off, how much counter measures are needed to get where one wants to go in the time one has to spare and how soon to scale down the input so as not to overshoot the target.

As I read more, my admiration for the Fuji gadget grows and I can also sympathize with the technicians who have compacted all these options in a mute little cube with very few buttons to press and just eight seven-segment displays plus a handful of tiny lights that can be on, off or flickering to take commands or talk back to you about a thousand things happening.

It's like writing and reading a novel using only the keys and the display of a telephone from the nineties. It would be very helpful to connect a computer and use big screens filled with menu options and help screens but one has to make do with the manual, the buttons and the byte size 'words' on the micro-display.

Later, when all has been set up, if the right cables have been acquired and connected and the communication protocols have been made to agree on both sides, the PXG4 will be able to talk to the USB and the Artisan software will be taking over control, enabling me to set out a roasting profile for the PXG4 to implement.