PLC-to-EPICS interface

In order to interface the application which at lower level use Allen-Bradley ControlLogix PLC control system we use ether_ip EPICS river/device support module. This allows us to interface EPICS records to PLC tags using Ethernet connection. On the PLC side the connection is provided by EN2T modules which communicate using through PLC's EtherNet/IP protocol. Overall this method seems to be working, but requires some coordination in the programming and notations to avoid complications when creating EPICS/PLC interfaced applications.

• Create CSV-file using RS5000 program and run script to generate EPICS database.
  1. When generating the CSV-file we should make sure that the tags imported from EPICS applications using EtherIP are not included.
  2. Only use DINT and REAL arrays. Other type of arrays are not guaranteed to work at this point.
  3. The perl script will not import the alarm tags into EPICS. They need to be included through a separate application/database for alarms.
  4. Use a separate set of PLC tags for input and output to EPICS. Using two-way communication using a single pair PV/tag for communication may turn into a problem.
  5. The alarm tag naming convention should be established.