Notes:Relay operate a switch and does not deliver power, so
user should prepare power adapter for external devices which
connects to relay.
3.8.3.Private Key Management
Valid private key information will be shown in the list.
Administrator could delete private key information or empty all
the list.
Go to Intercom->Relay, to configure relay.
There are three terminal of relay: NO, NC and COM. NO
stands for normally open contact while NC stands for normally
closed contact.
Relay ID: R27A/C supports three relays, user can configure
them respectively.