Below is a diagram of the front panel. The main attractions are the two four-digit displays which will mostly show the two most interesting temperature values:
PV (Process Value) being the measured temperature in the beans as a result of the manipulations of the PID, and
SV (Set Value), the temperature level that's the current target for the PID to approach.
The tiny light of C1 indicates if the heater is on or off and when it's 50% on, the light quickly flickers on and off, showing a half-dimmed light intensity.
The SV light blinks when the heater is adding energy to raise the temperature or to keep it at the current level.
The A/M User key on the bottom left is used to flip through the different channels/pages of all the possible modes and settings and the SEL key is used to select any one of the options that can be browsed in any given mode/menu using the up/down arrow keys.
For instance, when you're in the normal operation mode and you press and hold A/M, the SV display changes to display the output value that drives the SSR and thus the heating element, between -3% and 103%.
|Front panel diagram|
It basically tells you that you dig into lower levels of the menu by holding the SEL key, on the given level you browse the options using the arrow keys, press SEL to select one and then return to the home menu by pressing A/M.
I will show the things we need to set to get going (thanks Wa'il for pointing these out).
Other settings, like a 'mask' to prevent visitors from accidentally changing any parameters in deep hidden layers of the menu structure or a password protecting these critical settings can be figured out leasurely at a later moment.
Luckily, some values and settings regarding the control of a motorized valve can be ignored on this setup. This makes the puzzle easier to solve.
|Basic map of all menus|
|Thermocouple or other ways to provide Process Value input to the PID|
|Changing the PV Input setting|
Luckily, I have an SSR, a Solid State Relay that switches on and off without a physical moving part so I can afford to have it click on/off every one or two seconds.
|Brief explanation of contact/clicking output or SSR|
|Setting the output cycle. We keep it 1-2 seconds for the SSR|
|Beans to cool? Raise heat.|
|Setting "Heating only", keep it "rv--" as is in step 2|
|Ramp, Soak and Spike|
|Time units, we keep these to mm:ss as in step 2|
Tip from Wa'il: It's best to first do an auto-tune (see below) without beans, then change PID control to Fuzzy and then do an auto-tune again with beans as described below.
|Making sure the PID uses Fuzzy logic|
We take 230g of beans to sacrifice, load the roaster, set SV to the temperature of first crack, for instance 204ºC, and when it reaches that temperature we switch on Auto-tune where the PID will figure out its own optimal values for P, I and D.
|Have the PID finds its own best settings|
|Things to remember about Auto-tuning|
|P, I and D values can be altered, but proceed with caution.|
This "digital in 1" switch can be assigned the job this way:
|A number of options for DI-1|
|Selecting "13" for DI-1 selects Ramp/Soak to Run / Hold, "42" would only select Run|
|Only one Digital In here, so go to step 6|
Before starting any operation, the PID needs to be on for 30 minutes or else it might be confused about the exact temperatures:
A to-do list suggested by Fuji, with the subjects mostly covered in these blogs:
|Fuji's step-by-step advice|
For communications to the computer, I ordered the PXG/PXH Serial Cable TK4H4563-E from Fuji. It looks like this in the manual:
|PXG/PXH Serial Cable|
Ref : TK4H4563-E
To provide RS232-to-USB connectivity, I ordered these from CONRAD (sorry no currently active links at their updated website):
That's it for now! It seems I'm ready for the Fuji PGX4 to arrive.
PS 13 sept 2020 some screen snapshots of my current Artisan setup pages: