**Category: **Toolbox > eDrives >** **eMotors
(Legacy)** > **Controllers > PID Control

**Inputs:**

•**command:** Indicates the input signal to PID controller.

•**measurement:** Indicates the controlled variable input measurement
for PID controller.

•**Integrator Reset:** Resets the integrator. If held high, it latches
the integrator to the specified initial condition. Momentary reset can be
accomplished by using an external one shot resume.

**Output:**

•**Output:** Indicates the PID controller output signal.

**Description:** The PID Controller-Digital block is
discrete time PID, feed forward compensator.

The PID Controller-Digital block models a PID compensator as if implemented on a processor using either backward-rectangular approximation or the higher precision trapezoidal method for integration and filtering. This block provides anti-windup of the integrator component by separately calculating the PDF components, comparing this to the actuator saturation limits, and setting integration limits at each time step. PIDF, IF, PD, I, or P control can be implemented by choosing 0 gains for the unused components.

Band limiting filters are provided for the proportional and
derivative components. Derivative bandwidth specification guarantees no more
than 10^{o} phase difference at that frequency as compared to true
derivative. A rooftop filter is used to provide roll-off at high frequency. A
simple second order low pass filter is used to limit proportional component
bandwidth.

**Actuator High Saturation Limit:** Defines the upper
operating limit of the device connected to the PID output.

**Actuator Low Saturation Limit**: Defines the lower
operating limit of the device connected to the PID output.

**Controller Clock Frequency:** Sets the update rate of
the PID compensator.

**Derivative Bandwidth:** Indicates the limiting
frequency of the derivative component of control.

**Derivative Gain:** Indicates the multiplying factor
for the derivative component of control.

**Feed forward Gain**: Indicates the multiplying factor
for the control component that feeds directly from the input to the output of
the PID controller.

**Integral Gain:** Indicates the multiplying factor for
the integral component of control.

**Integrator Reset Value:** Defines the value at which
the integrator is initialized upon setting the Integrator Reset input high.

**Proportional Gain:** Indicates the multiplying factor
for the proportional component of control.

**Proportional Bandwidth**: Indicates the limiting
frequency of the proportional component of control.

**Use Higher Precision:** When this parameter is
activated, Tustin’s method of integration is used for higher precision in
integration and filtering. When this parameter is de-activated, backward
rectangular integration is selected.

**Diagram name: **Discrete PID Controller

**Location: **Examples > eMotors (Legacy) >
Brush DC

The following example illustrates the use of the PID compensator in shaping the dynamic response of a position control loop in feedback with a DC torque motor and rotary optical encoder. A profiler issues a command to move from 0 to 3 rad, and back to 0.