ActronAir BMS Interface Card ICUNO-MOD manages MODBUS 485 BMS integration, system ON/OFF, zone control, and compressor capacity management on ActronAir split ducted systems, ensuring reliable operation across all operating modes and fault conditions. Without a functioning board, loss of all BMS integration and building automation control -- the system cannot operate safely and will not restart until a genuine replacement is installed. Isolate power at mains before replacement -- live work on electrical components is dangerous and must only be performed by a qualified technician.