Delta MS300 Series User Manual page 411

Chapter 12 Descriptions of Parameter SettingsMS300
 PID control output frequency is filtered with a primary low pass function. This function can filter a
mix of frequencies. A long primary low pass time means the filter degree is high and a short
primary low pass time means the filter degree is low.
 Inappropriate delay time setting may cause system oscillation.
 PI Control:
Controlled only by the P action, so the deviation cannot be entirely eliminated. In general, to
eliminate residual deviations, use the P + I controls. When you use the PI control, it eliminates
the deviation caused by the targeted value changes and the constant external interferences.
However, if the I action is too powerful, it delays the response when there is rapid variation. You
can use the P action by itself to control the loading system with the integral components.
 PD Control:
When deviation occurs, the system immediately generates an operation load that is greater than
the load generated only by the D action to restrain the deviation increment. If the deviation is
small, the effectiveness of the P action decreases as well. The control objects include
applications with integral component loads, which are controlled by the P action only.
Sometimes, if the integral component is functioning, the whole system may oscillate. In this
case, use the PD control to reduce the P action's oscillation and stabilize the system. In other
words, this control is useful with no brake function's loading over the processes.
 PID Control:
Use the I action to eliminate the deviation and the D action to reduce oscillation; then combine
this with the P action for the PID control. Use the PID method for a control process with no
deviations, high accuracy, and a stable system.
Serial connection
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