Ei Electronics Ei408 alarm add-on RF module 868 MHz purchased inexpensively from Mercateo

The Ei408 is a RadioLINK interface module that accepts a Volt-free switched input from a hard-wired set of contacts (e.g. flow switch contacts on a sprinkler system) and sends out a corresponding RadioLINK alarm signal. - The Ei408 uses advanced transceiver and signal coding technology to ensure robust and reliable RF signaling. It also has a House-Code feature that allows a system of RadioLINK units to be coded together to prevent interference with neighboring systems. - It is powered by built in tamper-proof Lithium cells which are designed to last the life of the module. The cells are monitored and an end of life indication is given when the cells are depleted. - It is designed to be remotely sited and comes complete in its own enclosure. Operation - On receiving a Volt-free switched hard-wired signal, the unit will transmit a RadioLINK alarm signal. - When the switched hard-wired signal ceases and switches back to its normal standby position, the unit will cease sending out a RadioLINK alarm signal. - The unit can be House-Coded by activating the House-Code switch. The indicator will flash red to indicate that the unit is sending out its unique HouseCode. - The indicator will flash green every 40 seconds to indicate that the Lithium cell power supply is healthy. - If the Lithium cells are depleted, the indicator will flash amber every 10 seconds.