This European Standard specifies the minimum equipment requirements for the performance@ reliability@ resilience@ security and safety characteristics of the receiving centre transceiver (RCT) installed in ARC and used in alarm transmission systems. The alarm transmission system requirements and classifications are defined within EN 50136-1. Different types of alarm systems may in addition to alarm messages also send other types of messages@ e.g. fault messages and status messages. These messages are also considered to be alarm messages. The term alarm message is used in this broad sense throughout the document. Where application specific standards exist@ the RCT should comply with relevant standards called up by that application. The RCT can be either an integrated element of any receiving/annunciation equipment@ or a standalone device. In either case@ the requirements of this European Standard should apply. The function of the RCT is to monitor the ATPs@ receive alarm messages@ forward alarm messages to one or more AEs and send acknowledgements to the SPTs. Management of the transmission network is not in the scope of this European Standard.