860-540-002 HYYP dialler interface Required when connecting to control panels DTMF You might also be interested in: 860-36-0001 / 860-540-003-1 IDS Modem / HYYP Bi-directional Modem 860-36-0603 HYYP TCP / IP module 860-36-0603-03 HYYP IP Wifi module