The PXX-PBUS extension module allows for integrating existing PTM I/O modules in Desigo. The PXX-PBUS extension module, when combined with a modular series PXC..D automation station and one or two TXS1.12F12 supply modules, replaces the UNIGYR and VISONIK process units as well as the PXC64-U, PXC128-U automation stations.