Experimental Physics and
Industrial Control System

Hi Daniel,

We’ve got a couple of CX9020 PLCs integrated into EPICS. One of the PLCs is running TwinCAT 2 and the other is running TwinCAT 3. As already mentioned there are a few options of integrating Beckhoff embedded PCs into an EPICS system but we are using the EtherCAT bus. If you aren’t already using EtherCAT or don’t plan to then I’d probably not go down this path as it will take more time to get working. If you would like to use the EtherCAT bus then you’ll have to buy the EtherCAT slave peripheral for the CX9020. Then the basic steps we do are:

1) In TwinCAT write your PLC program (we are using structured text)

2) For the PLC variables you would like to expose to the EPICS mastered EtherCAT bus create matching variables in the EtherCAT slave peripheral. This is done in TwinCAT as well of course

3) In TwinCAT link the PLC and EtherCAT slave variables

4) On the EPICS master side create the ESI file for the embedded PC. I use “ethercat xml” as the basis of this operation

5) Use the DLS EtherCAT package tools to create the scanner configuration and the DB template files as you would normally.

Damien