PLC communication

This driver is intended to connect Siemens S7 PLCs (programmable logic controllers) via TCP/IP to an EPICS IOC, using the so called "send/receive" protocol. However, it can be used for any device sending and receiving blocks of process variables (PVs) in the same way. I highly recommend to connect the PLCs to the PC on a separate physical network using a second network interface to avoid connection problems.

The driver has originally been developped for SLS (Swiss Light Source) in 2000. Later is has been modified by DESY (Deutsches Elektronen Synchrotron). The current version has been completely rewritten for PPT (Puls-Plasmatechnik GmbH) to run on a R3.14.6 (or higher) PC based system, but it can also run on R3.13 vxWorks systems.

Read the full driver documentation and Yu-Han Lin's PLC configuration document (PDF). Maybe this example Step7 project also helps you to find a starting point for the PLC setup. But don't ask me any questions about it. I don't know anything about Step7.

Download the driver package s7plc.tgz (30906 bytes).

Author: Dirk Zimoch

To make your own EPICS R3.14 drivers R3.13 compatible, you might want to use the compatibility header file that I used in this driver. It translates many of the new EPICS R3.14 funtions back to R3.13 and vxWorks. (It is included in s7plc.tgz.)