The IA-3135-2 is an intelligent 8 Relays module, with 8 Isolated Digital inputs that is controlled by a Multi-Drop RS-232 communication method, and is a part of the IA Multi-module system. The 8 Digital Inputs has a wide voltage operation range, from less than 5V up to over 30V, and may be used as Isolated inputs, NONIsolated inputs or dry contact inputs. Special structure is provided to enable a simple wiring in one hand, and channel to channel isolation, if needed, in the other hand. Digital inputs and relays states are locally displayed, while modules address and modules initiate output states may be easily defined by software. Up to 256 IA-3135-2 modules, or any mix of IA modules may be easily controlled by a host computer or PLC, through a single COM port.