ABB ControlMaster CM30 User Manual

Also see for ControlMaster CM30: Communications supplement User guide User guide Manual Manual

Contents

ABB ControlMaster CM30 User Manual Manual pdf 95 page image

ControlMaster CM30, CM50 and CMF310Universal process controllers, 1/ 4, 1/ 2 DIN and fieldmount 8 Templates and FunctionalityIM/CM/ED–EN Rev. X 938.3.3 Cascade with FeedforwardThis template connects 2 PID loops together in order to enhance the control of a Master variable (loop) bymanipulation of a slave loop. The first (master) controller provides the set point for the second (slave)Controller. The 2 controllers are linked internally.To the Master output a feedforward signal is added. This signal is a disturbance variable which is weightedby the feedforward ratio and bias values. When the auto/manual mode is changed via the front panel or bya digital signal both the master and slave controllers change mode, the slave setpoint can then be adjustedfrom the front panel, and this value is then tracked by the Master controller (taking account of thefeedforward signal) to ensure a bumpless transfer back into auto mode.Note. As part of the cascade template, logic equation 1 is preconfigured.Changes to this equation will result in the cascade template not functioning correctly.AIN 1AIN 2AIN 3AIN 2PV 1LocalSet Pointx Ratio+ Bias(Slave)Loop 2PIDControlPIDO/PManualOutputLocalSet Pointx Ratio+ Bias AnalogOutput AO1OPOutput TypeSPVSSPMotorizedValveSplitOutputRLY1RLY2RLY1OP2OP11 Cascade with Remote Setpoint Only1Time PropOutput(Master)Loop 1PIDControlPIDO/PMPVMSPFFMSPAIN 2AIN 4x Ratio+ BiasLocalSet PointLocalSet PointLoop 1PIDControl(Master)PIDO/P2 Time PropOutputMotorizedValveSplitOutputAO2RLY1RLY2RLY1OP2OP1Output TypeAnalogOutputManualOutputMPVSSPSPVLoop 2PIDControl(Slave)AIN 3AIN 1**Source can be changed in Control / FeedForward configuration – see Section 7.4, page 46PIDO/P 1 x Ratio+ Bias