The MRI-4040 Dual Input Module is an intelligent addressable device designed to be used with a compatible fire alarm control unit, providing a high rate of exchanged information with fast and secure responses. The module can be used for alarm, supervisory, or monitor type applications. The MRI-4040 Dual Input module provides 2-independent contact monitoring circuits only utilizing 1-address on the SLC loop. The module supports 1 Class A or 2 Class B inputs. When configured for Class A operation, the module provides an internal EOL resistor. When configured for Class B operation, the module monitors 2-independent input circuits using only 1-module address. The module has a panel-controlled LED indicator. The LED flashes during normal operation and stays ON steadily when the device is in alarm condition. The address of each module is set using the MIX-4090 programmer tool. For setting the address on this device, disconnect it from the loop, or ensure that the loop to which is connected is both disconnected from the panel and shorted across the SCL+ and SLC- inputs at the device. Failing to take either of these steps may change the address programming of previously configured sensors on the loop.