Sunday, July 31, 2016

Coffee-Tech FZ-94 working seamlessly with Artisan

Artisan 1.0 screen with sliders for FZ-94 on the left

Recently, we received the opportunity to get an FZ-94 lab roaster and see how this roasting machine could work seamlessly with Artisan. An inspired back-and-forth between Marko Luther on the Artisan side in Germany and the R&D team of Coffee-Tech in Israël ensued and soon, the first machine was communicating fully with a newly expanded and freshly compiled version of Artisan.

Marko will explain the technical details in a separate blog post. Some details can be read in the release history.

One of the things in Artisan that were greatly expanded is the amount of MODBUS channels that can be communicated with at the same time. The new FZ-94 can communicate, over its MODBUS ring, the values of the current Bean Temperature, Drum Temperature, Exhaust Temperature and also the current setting of the frequency drives that control Drum Speed and Air Flow.

This involved internally hooking up the two frequency drives in the FZ-94 machine which was impossible until then Furthermore, the speed of communication was more than quadrupled using a different coordination of the internal settings and a new set of communication paramaters within Artisan.

Above I have posted a screen snapshot showing the new sliders that allow you to use the mouse to remotely control the Fan.

Switch the fan ON and OFF using the buttons at the bottom of the screen and use the slider on the top left to change the speed in percentage of the minimum/maximum values which can be separately changed in the background so you could have a minimum of 40 and a max of 95 of the actual power range and thus prevent a situation where you accidentally have no airflow at all.

Similarly, buttons to switch the Drum rotation ON and OFF and a slider to control speed, where 30% roughly equals 30 rotations per minute, 60 = 60 et cetera.

With HY1 and HY2 you can select what hysteresis you prefer for the PID control of the Drum Temp, 1ºC of 2ºC of deviation before the PID switches the heating elements ON or OFF.

The 3H - 2H - 1H - 0H buttons are there to click if you want to visualise, in the log graph, when you manually flipped the matching ON/OFF switches of the three individual heating elements on the FZ-94. These elements can not be switched ON/OFF remotely from within Artisan.

The two SV sliders may confuse you at first so I will explain a bit about them from my viewpoint as a user.

The SV-BT slider sends the desired DT value to the FZ-94. In the setup menu that controls the functionality, you can decide between which minimum/maximum values you have the 'spread' of 0-100%, so the 70% of the example could correspond to a set value of 180ºC, meaning that the DT PID on the FZ-94 will switch off the heating elements if the Drum Temp is over that value.

The SV slider next to it is not taking orders from the user, but it will show what value the current target is during a roast, if the automatic PID driven "Follow Background Roasting" is activated. So you can observe that slider climbing by itself if you have activated the internal PID control.

Example of the PID Control menu, popped up with the CONTROL button on the top right of the screen
Above is a sample snapshot of the PID control menu. Change the values to your liking and start background roasting by clicking "On" on the bottom left of this menu.

Of course, automatic background roasting must never be considered a way to have Artisan and a machine work standalone while you are on the phone, or making a dash to the restroom. Like driving a Tesla in autopilot, you must be actively involved in monitoring all the happenings and ready to take over control at any moment.

It does make it more easy to repeat a successful roast and it enables you to more quickly train a colleague to follow your previous steps.

In this setup, the FAN is used to drive the "auto pilot" along the designed roast profile or along a previously successful roast profile. If the current BT value is lower than the target, the FAN is at minimum value, for instance 40% and when the BT rises above the target, the FAN value will be increased slightly if the correction to be made is minor, up to the preselected maximum air flow if the deviation from target is getting more significant.

This is an experimental feature and its success depends on having a realistic background profile and a machine that is sufficiently warmed up at the CHARGE of the beans so the starting position of BT is more or less the same as the BT at CHARGE of the roast profile you mean to repeat.

Example of a roast profile that yielded delicious coffee

Above is an example of the second test run that we did with this feature. I activated the internal PID at TP around 1:30 into the roast and you can observe the SV line there, jumping up and tracking the background profile. Because the background was a little above the actual BT, the Fan was mostly at its default minimum (I believe it was 50%) and only after FC it got more active to steer BT along the planned curve in the background.

The grey line and blocks show where I switched off the 3 elements, namely one before 9:00, the second around 12:00 and the last one near 13:00 into the roast. Apart from three blips, the Rate of Rise nicely decreased towards DROP and that may explain why this roast was, as of this writing, the best so far.

Another possibility which we found very workable that does not make use of the internal PID, is a series of "Alarms" which can be used to sequentially report certain events like significant temperature  points along the profile and it can also automatically change variables like Drum Speed and Fan Speed to repeat a previously successful roast of which you have saved these essential data. You can, on a Mac, even invoke voice messages over the speaker to announce certain events and to prompt you, for instance, to listen for First Crack, or to remind you to switch off an element at certain previously marked BT values.

An example if such a plan as entered in Config-> Alarms is posted below:

A pre-planned set of settings during a roast
This is a list of things that will happen from the CHARGE of the beans until the end of cooling. As you see, it even makes sure you consistently cool the beans for the same duration so you can evaluate the effect of changing that one variable. The cooling mechanism of the fairly silent FZ-94 is so powerful that 1kg of beans is cooled down very quickly.

Meanwhile there is a third method of control to repeat a previous roast that I have not played with yet. In this Event Playback the sliders will move at exactly the same moments to the same values as noted in the background profile. Of course this assumes too that one starts at the same temperature with a similar load and beans.

FZ-94 ready to roast
We have currently set up the machine in my home in Amsterdam, near a window and a large 100W fan helps blow out any fumes coming out of the exhaust. Thanks to the propellers of the fan disperse the smoke very effectively during the brief minutes that there is some of that, my neighbours have not had a problem with my larger volume roasting.

I hope to post more soon!

(This blog entry is a copy of the one published on the Kostverlorenvaart blog)

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