We support Siemens ISO on TCP with S7_200, S7_300, S7_400 and according VIPA models (S5 is not tested jet). The basic class is rlSiemensTCP . In order to create a Siemens TCP daemon you choose "Daemon->SiemensTCP" in pvdevelop. Now you can edit a small INI-File, which describes what to read from the PLC's.
Within your pvserver now you can use rlSiemensTCPClient to communicate with Siemens PLC's.
We support Siemens serial line protocol PPI using libnodave on Linux and Windows. The PPI protocol is a very simple serial line protocol. But Siemens does not open this protocol. libnodave has reverse engineered the protocol. But unfortunately libnodave does not run on OpenVMS. In order to create a Siemens PPI daemon you choose "Daemon->PPI" in pvdevelop. Now you can edit a small INI-File, which describes what to read from the PLC's.
Within your pvserver now you can use rlPPIClient to communicate with Siemens PLC's.