Cascade control
Cascade Control is the technical name for a multi-loop control system where the air temperature set point (Inner Loop) is determined by deviation of the part temperature (Outer Loop) from its set point.
The controller is configured at the factory to allow the Air Temperature to deviate no more than +15°C or –15°C from the Part Temperature set point. This means if the set point is 85°C, the Air Temperature could go as high as 100°C if the Part Temperature lagged sufficiently during a heat up condition. In the example shown here, the Air Temperature went as high as 90.7°C when the Product Temperature achieved 83.0°C. Conversely, the Air Temperature went as low as 18.6°C when the Product Temperature achieved 23.4°C in order to reach a 23.0°C set point. In both instances, The Air Temperature then began to approach the Part Temperature as the part began to stabilize, until the two temperatures were ultimately nearly identical.