I have a Inovent RTU with carel controls and I'm attempting to bring the RTU onto a fx-60 via mstp. I'm able to discover the RTU and bring it into the FX but I'm having communication issues and the RTU is bouncing on and offline. The RTU is the only device on the mstp trunk and there's about 400 ft of wire between the RTU and the FX. Should I install a eol resistor at the RTU? Or may a repeater be needed?