Im trying to communicate to the AERCO BMS II through their communication gateway using N2 protocol. I believe I have the BMS modbus side of the communication running but I still can't get the NAE to see anything past the gateway in the auto discovery mode. I talked to tech support and everything seemed to be wired right and everything in the BMS was setup (passthru, baud rate, etc.). We then got to the BMS II address. Its default is set to 128. I had to change it to 129 because there is already an expansion module with the address 128. He told me that the BMS II has to be addressed 128 and that was why I could see anything past the gateway. I haven't been able to find the expansion module yet. My question is, has anyone had success communicating with the AERCO BM II and the benchmark boilers using N2 to Modbus? And does the BMS II have to be addressed 128 for it to work right?