Danfoss VLT FC 100 Series Manual

Also see for VLT AQUA Drive FC 200: Design guide Service manual Instruction manual Operating instructions Service manual

Danfoss VLT FC 100 Series Manual Manual pdf 23 page image

4. How to Control the Frequency Converter4.1. DeviceNet Process Control ModesThis section describes two of three possible process control modes: Polling and Change of State(COS).The third FC control mode uses the acyclical mode Explicit Messaging via the Standard DeviceNetControl Supervisory object CLASS 29H. The Control Supervisory object is described within theDeviceNet Object Classes section,How to Access the Parameters chapter.4.1.1. PollingThis is a classical Master-Slave connection andthe standard DeviceNet operation mode. Themaster controls the data exchange by sendingcyclical poll-requests to the connected slaves,and the slaves answers by sending a poll-re-sponse to the master. The master can controland monitor the frequency converter by poll-ing the DeviceNet or Danfoss objects (I/O In-stances).POLLED I/OMaster → slave CTW MRVSlave → master STW MAV4.1.2. Change of State, COSThis an event-controlled operation mode used to minimize network traffic. Messages are trans-mitted only if a defined state or value has changed. The condition for triggering a COS messageis determined by the insertion of COS-filters (parameters 10-20 to 10-23), for each bit in thedifferent PCD-words. The filter acts like a logical AND-function: If a bit in the filter is set to “1”,the COS-function triggers upon a change to the corresponding bit for the PCD-word.FC 100/ 200/ 300 DeviceNet 4. How to Control the Frequency ConverterMG.33.D3.02 - VLT® is a registered Danfoss trademark 234