SMC Sierra Monitor FS-8704-14, Руководство пользователя

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EtherNet/IP Driver Manual
Page 23 of 42
Appendix A.6 Configuring a FieldServer to Read/Write Data to/from a PLC with Explicit Messaging
This example makes use of the Data Table Read/Write method for passing data between the FieldServer
and an Allen Bradley PLC. The example shows configuration of a ControlLogix PLC, but all RockW
ell PLC’s
that support EtherNet/IP communications and Data Table Read/Write operations in Message blocks should
be able to communicate this way. These map descriptors will create an explicit connection to the server
and will then transfer data in the data table format. The EIP_Tag_Name field contains the tag name
referenced in the server and the EIP_Path field represents the path (through different ports) to the server.
Each port jump is separated by a space. This field generally holds a backplane/cpu slot combination.
DATA_TABLE_READ and DATA_TABLE_WRITE are the only legal values for EIP_SERVICE.
Note that this is by far the preferred method for communicating with Allen Bradley PLC’s due to its ease of
configuration, quantity of data that can be transferred and speed of transfer.
When the FieldServer is the active component as shown below (i.e: the FieldServer Polls the PLC and not
the other way around), then very little programming is needed in the PLC, other than the Tag Creation and
setting the PLC IP Address.