Chapter 6 Applied Instructions MV_MIN ： Minimum output value (MV_MIN) Double word MOUT ： Manual output value (MOUT) Double word I_MV ： Accumulated integral value (I_MV) Double word MV ： Output value (MV) Double word Explanation: 1. The instruction is used to implement the PID algorithm. After the sampling time is reached, the PID algorithm is implemented. PID stands for Proportional, Integral, Derivative. The PID control is widely applied to mechanical equipments, pneumatic equipments, and electronic equipments. 2. The setting of the parameters is as follows. 6-168 Device number Function Setting range Description PID RUN _ Enabling the PID algorithm True: The PID algorithm is implemented.
False: The output value (MV) is reset to 0, and the PID algorithm is not implemented. SV SV Range of single-precision floating-point numbers Target value PV PV Range of single-precision floating-point numbers Process value PID MODE _ PID control mode 0: Automatic control When PID MAN is switched from ON to OFF, _ the output value (MV) then is involved in the automatic algorithm. 1: The parameters are tuned automatically for the temperature control. When the tuning of the parameters is complete, the device is automatically set to 0, and is filled in with appropriate parameters K , P K, and K . I D 2:
Automatic control When PID MAN is switched from ON to OFF, _ the MV involved in the internal algorithm is involved in the automatic algorithm. If the setting value exceeds the range, it will be counts as 0. PID MAN _ PID A/M mode True: Manual The MV is output according to the MOUT, but it is still within the range between the MV MIN and the MV MAX. When _ _ PID MODE is set to 1, the setting is _ ineffective. False: Automatic The MV is output according to the PID algorithm, and the output value is within the range between MV MIN and _ MV MAX. _