Eaton PowerXL DX-NET-SWD Manual

4 Commissioning4.4 Acyclic data48 DX-NET-SWD 06/13 MN04012009Z-EN www.eaton.com4.4.4 Acyclic parameter channel for DX-NET-SWD34.4.4.1 IntroductionThe acyclic parameter channel is used in order to configure the parametersof the DC1 variable frequency drive; it corresponds to PROFIdrive profile.The following sections describe the parameter channel’s functions.4.4.4.2 ProtocolThe basic task of the SmartWire-DT interface card DX-NET-SWD3 is torepresent the protocol in such a manner that the parameter channel can beoperated completely transparent from the SmartWire-DT. Regardless ofwhether data should be read or written, the first request from the coordina-tor will always be a write request. A parameter request is used to definewhether the job is a read or a write job. After the write request is transmitted(contains read or write job), a write response without data will be expected.Then the coordinator poles through the read request of the variable fre-quency drive, prompted by the application of the higher level PLC. This keepsacknowledging the read request as negative (Error: State Conflict) until theread response has been completed and a reply (read order: with data/writerequest: without data) can be sent.Figure 17: Acyclic parameter channel protocolClientSWD Error OK orErrorOK orErrorOK orErrorSWD ErrorSWD ErrorParameterRequestParameterRequestError orno DataError orno DataParameterResponseParameterResponse(pos./neg.)ParameterProcessingDC1SWD Write RequestSWD Write Response(no Data or Error)SWD Read RequestSWD Read Response(no Data or Error)SWD Read RequestSWD Read Response((no) Data or Error)SWDDC1