AH500 Programming Manual Example: 1. Before the instruction PID is executed, the setting of the parameters should be complete. 2. When X0.0 is ON, the instruction is executed. When M1 is ON, the PID algorithm is implemented. When M1 is OFF, the MV is 0, and the MV is stored in D200. When X0.0 is switched OFF, the instruction is not executed, and the previous data is unchanged. Additional remark: 1. The instruction can be used several times, but the registers specified by I_MV ~ I_MV +5 can not be the same. 2. I_MV occupies 12 registers. I_MV used in the instruction PID in the above example occupies D122~D133. 3.
The instruction PID only can be used in the cyclic task and the interval interrupt task. When the instruction PID is used in the interval interrupt task, the sampling time is the same as the interval between the timed interrupt tasks. 4. When the instruction is scanned, the PID algorithm is implmented according to the sampling time, and the MV is refreshed. When the instruction is used in the interrupt task, the sampling time is the same as the interval between the timed interrupt tasks. The PID algorithm is implemented according to the interval between the timed interrupt tasks. 5.
Before the PID algorithm is implemented, the process value used in the instruction PID has to be a stable value. When users need the input value in the module to implement the PID algorithm, they have to notice the time it takes for the analog input to be converted into the digital input. The PID algorithm: 1. When PID_MODE is set to 0 or 2, the PID control mode is the automatic control mode. 2. When PID_MODE is set to 1, the PID control mode is the automatic tuning mode. After the tuning of the parameter is complete, PID_MODE is set to 0. The PID control mode becomes the automatic control mode.
6-176 Data Setting Device number Function Description type range MV REAL MV The MV is withing the range between the MV MIN and _ the MV MAX. _