Realized at one point that since there's no map of how each wire goes where, not to mention that some of the wires lost their purpose during the time since not all of them were marked - that it's gonna get complicated soon if this isn't rectified. So there have been quite a few hours over this months of mapping out what goes where. A Visio diagram was also employed, and each wire colored as it is on the layout, complete with tool-tip comments that show a wire's function when hovering over it.
Work was done to the electrical panel that will contain all the modules (Viessmann, Phidget, etc.) so I can finally move away from the wiring-in-a-box approach.
Last but not least, since it turned out that quite a few wires will be required in the end, no less than 4 D-Sub connectors would be needed (37 pins/ connector, however because I'm using some 32-wire legacy cable, 5 of those pins will go unused). The required connectors, brackets and various other items were purchased; so far a connecting cable was built, the original connecting board got modified so that it holds 2 connectors, and a new enclosure for a similar cassette plus the corresponding board were just finished today.
