The automation of a process with PC-supported process monitoring and operation via software requires fast data interchange between the software and the individual accessories of a control loop. The use of fieldbus systems for this purpose is widespread in industry. PROFIBUS is a common standard in fieldbus communication. The protocol used by the RT 450.40 is the PROFIBUS variant PROFIBUS DP.
PROFIBUS communication networks have a hierarchical structure. PROFIBUS DP distinguishes between master and slave devices. The PROFIBUS master determines the data interchange. Slaves receive data or send data on request. Software, the OPC server, provides the interface between the fieldbus system and the process monitoring software.
With RT 450.40, the PCIe PROFIBUS DP card included in the scope of delivery serves as the fieldbus master. The RT 450.10 and RT 450.11 controllers or the PLC RT 450.42 are slaves. These must also be fieldbus-capable and must be equipped with a PROFIBUS module RT 450.41 or RT 450.43 accordingly. The GUNT visualisation software is used as the software.
An important feature of the visualisation software, based on LabVIEW, is a chart function for displaying time functions in order to be able to track the values of the signals in the control loop, such as reference value, controlled variable or manipulating variable. The RT 450.10 and RT 450.11 controllers can also be operated and parameterised via the software. Changes made by the software are sent directly to the slaves. Controller settings made using the buttons on the controllers are also sent to the software.