Honeywell TouchCenter communication issues and lightning control

Hi,
I'm having frequent (couple times a day) keyboard lost-problem with TouchCenter Plus connected to GD-48 (firmware 7.something). Keyboard diagnostics give connection quality varying between 0% and 100%. Cabling is Cat5 unshielded/ Cat6 shielded, last part to mk8 keyboard is 2-pair shielded Belden. There's short (about 20cm) internal run of untwisted 4-wire between panel and Ethernet module inside panel enclosure, this wire came with ethernet-module. Both ends have 680Ohm resistors and power supply is from panel. Total bus length is between 20m and 30m, closer to 20m I think. There's one Krone-row connector (located in main distribution board), where pairs are connected, pairs are correct, twisting has been preserved and topology is definitely bus, not star or something else. Picture of all devices and bus topology attached.

The weird thing, mk8 keyboard has communication quality of 100% and it's last device on bus after TouchCenter Plus. I have already tried with two different TC+, always same problem. Clear wire is connected on Cat6 between all the runs, haven't connected the shielding to anything, can it cause problem like this? If this is power-problem, I can supply ground level devices from separate power supply with battery backup used for smoke detectors, it has enoguh spare capacity. If problem is caused by shielding, should it be connected at both ends (panel, distribution board), or only single end (which one)?

And final question, I want to control lightning with TC+. I have partially correct configuration, since TC+ now sees outputs in lightning section and they can be toggled. I have set output type to Spare / Lighning / Toggle / Reflex, because there's no fundamental need to control them based on zones. However, outputs are now powered all the time, they don't follow TC+ setting. Is it necessary to set them to follow some zone, like log or something else, that doesn't cause/require real alarm? Or create link? Lights to be controlled are in such locations, that they are used only, when panel is unset or part set.

 

With the power off, what is the resistance of a and b with respect to 0v ?

I see this sort of thing a lot when people buy panels from ebay (not from my sales though). The fault is the reason they were swapped out in the first place.

The output control should just work. There's no zone requirement. Try setting 1002 as control and you should hear the relay click when switching.