Читать книгу Control of Mechatronic Systems - Patrick O. J. Kaltjob - Страница 19

The data processing and computing unit is used: (i) to control and regulate machine operations; (ii) to monitor machines and processes operations; and/or (iii) to coordinate operations within the same process. Data processing and computing could be performed either:

1 offline: that is, there is no direct or real-time connection between the process execution and the data processing and computing unit;

2 online for open-loop operations: that is, the protection (safety) of process operations and interlocking; or

3 online for closed-loop operations.

Commonly encountered data processing and computing devices are: digital signal processing devices, programmable logic controllers, microcontrollers, field programmable gate arrays among others, and a distributed control system (DCS) (consisting of a historian server connected to a network of field controller devices). Those devices execute program routines for: (i) the acquisition of process variables; (ii) process condition monitoring and exception handling (i.e. executing process safety operations); (iii) the control of machine operations (e.g. activation/deactivation of motor, tracking of motor speed); and (iv) the archiving and sharing of process data with other control devices through the communication network.