Various fieldbus protocols are integrated and configured directly with the central engineering tool in APROL, the CaeManager. To simplify driver configuration, a rule-based GatewayEditor is available in the CaeManager. When processed further, the input and output data supplied by the fieldbus modules and interface cards have the same complete support as conventional I/Os from System 2005 modules. Implementing any types of special protocols (scale interfaces, counter interfaces, etc.) is also easy since ANSI C can be used to completely program the fieldbus modules and interface cards.