Alpha Technologies IP Bell – 01 User And Installation Manual page 12

Fig. 3 Connection of the pushbuttons and visit cards illumination
Connection of switching contacts terminal is shown on fig. 2. Label
"NO" means normally open contact, "COM" means common outlet (middle) and
"NC" means normally closed contact. Contacts of both switches are isolated
galvanically from each other and also from other circuits of the IP Bell
doorphone. Variants of switches connection are shown on fig. 4 and 5.
12 IP Bell
- User guide and installation manual