I have a recent problem with a Hikvision PoE switch DS-3E1105P-EI/M that needs to feed a IP Door Intercom with DS-KH6320-WTE1 as a touchpad. Over short distances (<2m) the switch feed the power and the touchscreen identifies the ringbell connected to the switch, meaning it finds it on the network. But when I installed it on site (cable from touchscreen to switch around 20 m) the touchscreen does not find the ringbell on the network, and it doesn't work. I have so far changed from cat 5e to 6 to see if the problem solves but so far no avail. The doorbell and touchscreen came as a package with the switch DS-3E0105P-E/M(B) as the default PoE switch, but it broke and the same model is not available any more. So my question is, could it be a damage on the screen that works fine over short distances but over longer it does not receive the data well enough?. Or could it be a problem with the switch?. Mind you, I have make the test of putting the doorbell over the cable with long distance and connected the touchscreen close to the switch and it works just fine.Any help available would be much appreciated.