Danfoss Native BACnet VLT HVAC Drive Operating Instructions Manual

Contents

5.1.4 Real Time Clock VariableThe frequency converter has a built-in real-time clock. Thestandard real-time clock has no battery backup function,which will lead to a loss of time if the drive is un-powered.Some BACnet Master's can be programmed to send out thedate and time as a Broadcast Telegram on a regular basis.The BACnet Interface will update the real-time clock of thedrive if it receives the time synchronization telegram.5.1 Feedback to NetworkThe BACnet option provides several output variables (nvo’s)objects to the network, containing important -, motor- andI/O feedback data. The BACnet option transmits boundnetwork variables only and sends feedback data when thereis a change in value.Influence of the digital input terminals upon the ControlMode, 8-50 Coasting Select to 8-56 Preset Reference SelectThe influence of the digital input terminals upon control ofthe frequency converter can be programmed in8-50 Coasting Select to 8-56 Preset Reference Select.8-01 Control Site overrules the settings in parameters 8-50 to8-56 and Terminal 37, Safe Stop overrules any parameter.Each of the digital input signals can be programmed to logicAND, logic OR, or to have no relation to the correspondingbit in the control word. In this way a specific controlcommand i.e. stop / coast, can be initiated by the fieldbusonly, fieldbus AND Digital Input, or Fieldbus OR Digital inputterminal.In order to control the frequency converter via BACnet,8-50 Coasting Select must be set to either Bus [1], or to LogicAND [2] and 8-01 Control Site must be set to Digital and ctrl.word [0] or Controlword only [2].5.2 BIBBsReadProperty ExecuteWriteProperty ExecuteDeviceCommunicationControl ExecuteReinitializeDevice ExecuteI-Am InitiateI-Have InitiateTimeSynchronization ExecuteWho-Has ExecuteWho-Is ExecuteBACnet Objects VLT® HVAC Drive Native BACnet Operating Instructions20 MG.14.C1.02 - VLT® is a registered Danfoss trademark55