Setting 0: Triggered when a Run Command Is Issued (Normal)Setting 1: Triggered when an External Baseblock Is Releasedu b5: PI ControlThe drive has a built-in Proportional + Integral (PI) controller that uses the difference between the target value and the feedbackvalue to adjust the drive output frequency to minimize deviation and provide accurate closed loop control of system variablessuch as pressure or temperature.n P ControlThe output of P control is the product of the deviation and the P gain so that it follows the deviation directly and linearly. WithP control, only an offset between the target and feedback remains.n I ControlThe output of I control is the integral of the deviation. It minimizes the offset between target and feedback value that typicallyremains when pure P control is used. The integral time (I time) constant determines how fast the offset is eliminated.n PI OperationTo better demonstrate PI functionality, the diagram below illustrates how the PI output changes when the PI input (deviation)jumps from 0 to a constant level.PI inputI controlPI OutputTimePI outputTimeP controlFigure 5.11 PI Operationn Using PI ControlApplications for PI control are listed in the following table.Application Description Sensors UsedSpeed Control Machinery speed is fed back and adjusted to meet the target value. Synchronous control isperformed using speed data from other machinery as the target value TachometerPressure Maintains constant pressure using pressure feedback. Pressure sensorFluid Control Keeps flow at a constant level by feeding back flow data. Flow rate sensorTemperatureControl Maintains a constant temperature by controlling a fan with a thermostat. Thermocoupler,Thermistorn PI Setpoint Input MethodsThe PI setpoint input depends on the PI function setting in parameter b5-01.If parameter b5-01 is set to 1 or 2, the frequency reference in b1-01 or one of the inputs listed in Table 5.2 becomes the PIsetpoint.If b5-01 is set to 3 or 4, then the PI setpoint can be input from one of the sources listed in Table 5.2.Table 5.2 PI Setpoint SourcesPI Setpoint Source SettingsAnalog Input A1 Set H3-02 = CAnalog Input A2 Set H3-10 = CMEMOBUS/Modbus Register 0006 H Set bit 1 in register 000F H to 1 and input the setpoint to register 0006 H5.2 b: Application128 YASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual
