The LCN-R1U is a relay without its own processor for flush-mounted installation with a potential-free contact (changeover contact) for connection to an LCN-UPP, LCN-UP24 or LCN-UPS. It can be used on any other LCN module with a T-connection. The relay module provides the user with an additional switching contact for each UP module. This can be used in particular for switching sockets or for controlling heating actuators. The two electronic outputs of the LCN-UPP are also available.