Appendix B.4. Understanding buffer types and Map Descriptor functions
The diagram belowexplains the data flows for both | buffers when using the FieldServer as a DN |
Master: |
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NotethatfortheInputbuffer,thedataiscoming fromtheexternalDNSlaveandistransferredinto theDNMastercard’sinternalinputbuffer.TheRdb c(ReadDataBlockContinuous)MapDescriptor transfersthedatafromthecardbufferintotheFi eldServer’sDataArraypackingitcorrectlyaccordi ng tothespecifiedDeviceNet_Data_Type.
FortheOutputbuffer,thedataiswrittenfromthe FieldServer’sDataArraybytheWRBCfunction MapDescriptor(WriteDataBlockContinuous)intot heDNMastercard’sinternaloutputbufferfrom whereitistransferredacrosstheDeviceNetnetwor ktotheexternalDNSlave’sinputbuffer.
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DataArray |
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WRBCMapDescriptor | RDBCMapDescriptor |
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| DeviceNetCard |
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| DeviceNet |
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| Cardinputbuffer |
| Network | Cardoutputbuffer | |||
| 0 | 1 | …. | 243 | 0 | 1 | …. | 243 |
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| 0 | 1 | …. | 243 | 0 | 1 | …. | 243 |
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| ExternalDNSlave126 | ||
Note:TheNode_Namedeterminesto |
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| Cardoutputbuffer |
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whichexternalDNSlavedatewillbe |
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senttoorfetchedfrom. |
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| 0 | 1 | …. | 243 |
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| Cardinputbuffer |
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| 0 | 1 | …. | 243 |
Appendix B.5. Accessing Parameter Data in Remote Slaves
TheDeviceNetdriveronlysupportsIOdata.Toacce ssparameterdataonSlavesitisnecessaryto refertotheSlavedevice'susermanualsforinform ationonhowtomaptheirparameterdatatoIO datalocations.
FieldServer Technologies1991TarobCourtMilpitas,California95035USA | Web:www.fieldserver.com | ||
Tel:(408)2622299 | Fax:(408)2622269 | Toll Free:(888)5091970 | email:support@fieldserver.com |