Databases in automated process control

This report describes practical experiences in building systems for manufacturing and robotics. Transporting plants are a typical example for the integration of database systems and real-time systems. This is due to the fact that general administration, workflow control as well as physical movements of conveyor systems have to be coordinated. In practice, plant engineers were forced to develop pragmatic but working concepts to bring real-time issues and database principles under a single roof. The most common approach is based on a hierarchical network of two different types of computers-administration computers and control computers-to handle database services or real-time services, respectively. In such a setting, recovery for real-time computers can be achieved by means of downloading the relevant data from a database-supported administration computer. Overall integrity requires communication supported by database services. Here, we treat the necessary transaction processing framework.