FieldServer FS-8704-14 - Manual (Page 19)

FS-8704-14 EtherNet/IP Manual Page 19 of 31
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Appendix A.5.2. The PLC Program
The PLC program example below shows the minimum steps necessary to program communications with the
FieldServer. Depending on the real intended application, additional steps may be necessary for completeness.
Step 1: Configure Tags in the PLC for storing FieldServer read and write data:
Step 2: Configure Message Tags for storage of Message Block data:
Step 3: Write Ladder Logic to exercise a Read and Write Message Block
NOTE: It is important to use the Ladder logic to ensure that only one Message block can be executing at any time.
Tag Length Must be equal to or greater than
the number of points being written/read
MESSAGE Data Type must be used.
Avoid Using UDT Types. The Data will
be read but the exact placement of
the data in the Tags and Arrays will be
hard to determine
Note that this logic shown will cause the PLC to poll the FieldServer at a
very high speed. This may overload network traffic - logic that schedules
the communication at a slower rate is generally more advisable.