The MD8 instrument is an external relay unit for use as an alarm expansion with any GEFRAN instrument that supports it.
The MD8 makes available up to 8 relay outputs wihch may be configured internally as normally open or normally closed contacts.
Eight logic outputs are available as an alternative.
Eight faceplate LED's illuminate in the relay energized condition.
A simple 3-wires connection links the unit with the "master" instrument.