LNK-IO20-RS-MOD Modbus RS485 IO Module with 20 I/OProduct Overview Link IO is an Open Protocol, distributed IO System with a 5 year warrantydesigned to help our System Integrators access any project from small to large without compromising quality or flexibility. Innon produces Link IO in collaboration withCAREL S. p. A, an Italian controls manufacturer trusted all over the world in critical control applications. The Link IO contains one main unit which can be either Modbus or both Modbus and Bacnet