The MRI-M500R Secutron Relay Control Module is intended for use in intelligent, two-wire systems, where the individual address of each module is selected using the built-in rotary decade switches. It allows a compatible control panel to switch discrete contacts by code command. The relay contains two isolated sets of Form-C contacts, which operate as a DPDT switch and are rated in accordance with the table in the manual. Circuit connections to the relay contacts are not supervised by the module. The module also has a panel controlled LED indicator. This module can be used to replace an M500C module that has been configured for Form-C operation.