Problems with cascade control

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We have some issues with our cascade control systems and need everyone’s help. First, there are two cascade controls; after the outer-loop cascade is activated, the MV value does not change in response to changes in the PV value, remaining at a constant level. The outer ring represents temperature, while the inner ring represents flow rate. After introducing the cascade control, whether the temperature rises or falls. The outer loop MV value remains constant, which causes the inner loop SV value to remain unchanged as well. It cannot be adjusted. Second, there is a cascade control system: the outer loop functions normally, but the MV value of the inner loop does not reach 0 when the SV value does. Is this related to the fact that there is still some flow when the valve is open by about 10 percent? I appreciate your help. Thank you