Heartbeats are used within OCPP to allow the charge point and the central system to ensure the charger still has an active connection. Your OCPP service provider may have a preferred interval at which such messages should be sent.
You can adjust the heartbeat interval by changing the HeartbeatInterval parameter in the OCPP configuration. This is defined in seconds.
Note: If the central system responds with a heartbeat interval within the bootNotification, zappi will automatically adhere to this interval. If no such interval is set, zappi will default to 60 seconds.