Rockwell Automation has introduced three advanced process control (APC) function blocks in the latest version of Rockwell Software RSLogix 5000 engineering software. Native to the Allen-Bradley Logix family of controllers, the new function blocks offer process users sophisticated APC technology that is simpler to implement. In addition, the company introduced a new redundancy module and improvements in system availability, further extending the capabilities of the company's process automation system. All are part of the Rockwell Automation continued focus on helping process customers improve their operations.
Process users across multiple industries, such as fermentation control in biotech, temperature control in glass manufacturing, chlorination and pH control in water treatment, and basis weight and moisture control in paper making, can take advantage of the new APC blocks. Since these applications have a longer dead time or interaction between multiple I/Os, process users often require a level of control flexibility that is not found in traditional PID-based systems.
The new APC blocks provide compensation for long, dead-time processes and allow simpler multivariable control with automatic tuning built-in. Control strategy implementation with the new blocks is straightforward and configuration is done within the RSLogix 5000 engineering software:
- Internal model control — Controls a single process variable by manipulating a single output using a predictive algorithm
- Coordinated control — Manages a single process variable by manipulating as many as three outputs. This technology is best applied when trying to optimize an economic constraint, such as energy consumption, to control multiple process variables.
- Modular multivariable control — Manages two interacting process variables to target values using up to three control outputs. Similar to coordinated control, this technology can help optimize multiple economic constraints to control multiple process variables.