We have one of our customers where we are setting up some Onicon System 10 BTU meters. They are on a separate stand-alone loop right now and when we connect them to the existing FX60 BACnet MS/TP trunk, it causes some of the other controllers to randomly go online and offline. We did discover a duplicate address on one of the meters and removed it. However, right now we can only leave two of the meters connected, because any more than that causes instability. I am not sure if it is simply the number of meters on the trunk. They all can't be bad. We still have to do more testing, but was wondering if anyone has encountered communication issues while using this hardware. A couple of days have already been spent on something that shouldn't take this long. I can scan the meter loop alone and see all of the meters, but as soon as we connect them to the bus, everything goes nuts. As a last resort, I have thought about placing them on their own dedicated loop, but this will incur more expense and I'm not sure if this will cure the problems.